<?xml version="1.0" encoding="US-ASCII"?>
<!-- RR Donnelley Xcelerate Taxonomy Labels Linkbase, based on XBRL 2.1  http://www.rrdonnelley.com/ -->
<!-- Version: 6.20.1 -->
<!-- Round: 8 -->
<!-- Creation date: 2012-11-08T01:51:52Z -->
<!-- Copyright (c) 2005-2012 R.R. Donnelley &amp; Sons Company All Rights Reserved. -->
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    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_AbrMember" xlink:label="oas_AbrMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_AbrMember_lbl" xml:lang="en-US" id="id_623015_616492_3_1">ABR [Member]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccountsPayableCurrent_lbl" xml:lang="en-US" id="id_623015_582420_1_1">Accounts Payable Current</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AccountsPayableCurrent_lbl" xml:lang="en-US" id="id_623015_582420_2_1">Accounts payable</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="us-gaap_AccountsReceivableNetCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccountsReceivableNetCurrent_lbl" xml:lang="en-US" id="id_623015_571324_1_1">Accounts Receivable Net Current</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AccountsReceivableNetCurrent_lbl" xml:lang="en-US" id="id_623015_571324_2_1">Accounts receivable - oil and gas revenues</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="us-gaap_AccruedLiabilitiesCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccruedLiabilitiesCurrent_lbl" xml:lang="en-US" id="id_623015_576774_1_1">Accrued Liabilities Current</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AccruedLiabilitiesCurrent_lbl" xml:lang="en-US" id="id_623015_576774_2_1">Accrued liabilities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccruedLiabilitiesCurrent" xlink:to="us-gaap_AccruedLiabilitiesCurrent_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_lbl" xml:lang="en-US" id="id_623015_580348_1_1">Accumulated Depreciation Depletion And Amortization Property Plant And Equipment</label>
    <label xlink:type="resource" xlink:role="http://xbrl.us/us-gaap/role/label/negated" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_lbl" xml:lang="en-US" id="id_623015_580348_8_1">Less: accumulated depreciation, depletion, amortization and impairment</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:to="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AdditionalPaidInCapitalCommonStock" xlink:label="us-gaap_AdditionalPaidInCapitalCommonStock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdditionalPaidInCapitalCommonStock_lbl" xml:lang="en-US" id="id_623015_581342_1_1">Additional Paid In Capital Common Stock</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AdditionalPaidInCapitalCommonStock_lbl" xml:lang="en-US" id="id_623015_581342_2_1">Additional paid-in-capital</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdditionalPaidInCapitalCommonStock" xlink:to="us-gaap_AdditionalPaidInCapitalCommonStock_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:label="us-gaap_AdditionalPaidInCapitalMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdditionalPaidInCapitalMember_lbl" xml:lang="en-US" id="id_623015_576438_1_1">Additional Paid In Capital [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AdditionalPaidInCapitalMember_lbl" xml:lang="en-US" id="id_623015_576438_2_1">Additional Paid-in Capital [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdditionalPaidInCapitalMember" xlink:to="us-gaap_AdditionalPaidInCapitalMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation" xlink:label="us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation_lbl" xml:lang="en-US" id="id_623015_571591_1_1">Adjustments Related To Tax Withholding For Share Based Compensation</label>
    <label xlink:type="resource" xlink:role="http://xbrl.us/us-gaap/role/label/negated" xlink:label="us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation_lbl" xml:lang="en-US" id="id_623015_571591_8_1">Treasury stock - tax withholdings</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation" xlink:to="us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationAndExerciseOfStockOptions" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationAndExerciseOfStockOptions"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationAndExerciseOfStockOptions_lbl" xml:lang="en-US" id="id_623015_581561_1_1">Adjustments To Additional Paid In Capital Sharebased Compensation And Exercise Of Stock Options</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationAndExerciseOfStockOptions_lbl" xml:lang="en-US" id="id_623015_581561_2_1">Stock-based compensation</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationAndExerciseOfStockOptions" xlink:to="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationAndExerciseOfStockOptions_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xml:lang="en-US" id="id_623015_566868_1_1">Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xml:lang="en-US" id="id_623015_566868_2_1">Adjustments to reconcile net income to net cash provided by (used in) operating activities:</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xml:lang="en-US" id="id_623015_566868_12_1">Adjustments to reconcile net income to net cash provided by operating activities:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_AdvancesFromJointInterestPartnersCurrent" xlink:label="oas_AdvancesFromJointInterestPartnersCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_AdvancesFromJointInterestPartnersCurrent_lbl" xml:lang="en-US" id="id_623015_617748_3_1">The total of the amounts received in advance for capital projects from our joint interest partners.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_AdvancesFromJointInterestPartnersCurrent_lbl" xml:lang="en-US" id="id_623015_617748_1_1">Advances From Joint Interest Partners Current</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_AdvancesFromJointInterestPartnersCurrent_lbl" xml:lang="en-US" id="id_623015_617748_2_1">Advances from joint interest partners</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_AdvancesFromJointInterestPartnersCurrent" xlink:to="oas_AdvancesFromJointInterestPartnersCurrent_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_AdvancesToJointInterestPartnersCurrent" xlink:label="oas_AdvancesToJointInterestPartnersCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_AdvancesToJointInterestPartnersCurrent_lbl" xml:lang="en-US" id="id_623015_617749_3_1">The total of the amounts paid in advance to a third party for capital projects that will be reclassified to PP&amp;E or expensed with the passage of time or the occurrence of a triggering event, which is expected to be within one year or the normal operating cycle (if longer).</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_AdvancesToJointInterestPartnersCurrent_lbl" xml:lang="en-US" id="id_623015_617749_1_1">Advances To Joint Interest Partners Current</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_AdvancesToJointInterestPartnersCurrent_lbl" xml:lang="en-US" id="id_623015_617749_2_1">Advances to joint interest partners</label>
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    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_AmendedCreditFacilityMember" xlink:label="oas_AmendedCreditFacilityMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_AmendedCreditFacilityMember_lbl" xml:lang="en-US" id="id_623015_615237_3_1">Amended Credit Facility [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_AmendedCreditFacilityMember_lbl" xml:lang="en-US" id="id_623015_615237_1_1">Amended Credit Facility [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_AmendedCreditFacilityMember_lbl" xml:lang="en-US" id="id_623015_615237_2_1">Amended Credit Facility [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_AmendedCreditFacilityMember" xlink:to="oas_AmendedCreditFacilityMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2012/dei-2012-01-31.xsd#dei_AmendmentFlag" xlink:label="dei_AmendmentFlag"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_AmendmentFlag_lbl" xml:lang="en-US" id="id_623015_565213_1_1">Amendment Flag</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="dei_AmendmentFlag_lbl" xml:lang="en-US" id="id_623015_565213_2_1">Amendment Flag</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_AmendmentFlag" xlink:to="dei_AmendmentFlag_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_lbl" xml:lang="en-US" id="id_623015_580039_1_1">Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_lbl" xml:lang="en-US" id="id_623015_580039_2_1">Anti-dilutive stock-based compensation awards</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:to="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AssetRetirementObligation" xlink:label="us-gaap_AssetRetirementObligation"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetRetirementObligation_lbl" xml:lang="en-US" id="id_623015_577302_1_1">Asset Retirement Obligation</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_AssetRetirementObligation_lbl" xml:lang="en-US" id="id_623015_577302_4_1">Balance at September 30, 2012</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_AssetRetirementObligation_lbl" xml:lang="en-US" id="id_623015_577302_5_1">Balance at December 31, 2011</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AssetRetirementObligation_lbl" xml:lang="en-US" id="id_623015_577302_2_1">Asset retirement obligation, carrying value</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetRetirementObligation" xlink:to="us-gaap_AssetRetirementObligation_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AssetRetirementObligationAccretionExpense" xlink:label="us-gaap_AssetRetirementObligationAccretionExpense"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetRetirementObligationAccretionExpense_lbl" xml:lang="en-US" id="id_623015_575714_1_1">Asset Retirement Obligation Accretion Expense</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AssetRetirementObligationAccretionExpense_lbl" xml:lang="en-US" id="id_623015_575714_2_1">Accretion expense during period (1)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetRetirementObligationAccretionExpense" xlink:to="us-gaap_AssetRetirementObligationAccretionExpense_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AssetRetirementObligationCurrent" xlink:label="us-gaap_AssetRetirementObligationCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetRetirementObligationCurrent_lbl" xml:lang="en-US" id="id_623015_572339_1_1">Asset Retirement Obligation Current</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AssetRetirementObligationCurrent_lbl" xml:lang="en-US" id="id_623015_572339_2_1">Total asset retirement obligations, current portion</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetRetirementObligationCurrent" xlink:to="us-gaap_AssetRetirementObligationCurrent_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AssetRetirementObligationDisclosureTextBlock" xlink:label="us-gaap_AssetRetirementObligationDisclosureTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetRetirementObligationDisclosureTextBlock_lbl" xml:lang="en-US" id="id_623015_569174_1_1">Asset Retirement Obligation Disclosure [Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AssetRetirementObligationDisclosureTextBlock_lbl" xml:lang="en-US" id="id_623015_569174_2_1">Asset Retirement Obligations</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetRetirementObligationDisclosureTextBlock" xlink:to="us-gaap_AssetRetirementObligationDisclosureTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AssetRetirementObligationLiabilitiesIncurred" xlink:label="us-gaap_AssetRetirementObligationLiabilitiesIncurred"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetRetirementObligationLiabilitiesIncurred_lbl" xml:lang="en-US" id="id_623015_582337_1_1">Asset Retirement Obligation Liabilities Incurred</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AssetRetirementObligationLiabilitiesIncurred_lbl" xml:lang="en-US" id="id_623015_582337_2_1">Liabilities incurred during period</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetRetirementObligationLiabilitiesSettled_lbl" xml:lang="en-US" id="id_623015_578785_1_1">Asset Retirement Obligation Liabilities Settled</label>
    <label xlink:type="resource" xlink:role="http://xbrl.us/us-gaap/role/label/negated" xlink:label="us-gaap_AssetRetirementObligationLiabilitiesSettled_lbl" xml:lang="en-US" id="id_623015_578785_8_1">Liabilities settled during period</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetRetirementObligationLiabilitiesSettled" xlink:to="us-gaap_AssetRetirementObligationLiabilitiesSettled_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AssetRetirementObligationRevisionOfEstimate" xlink:label="us-gaap_AssetRetirementObligationRevisionOfEstimate"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetRetirementObligationRevisionOfEstimate_lbl" xml:lang="en-US" id="id_623015_571892_1_1">Asset Retirement Obligation Revision Of Estimate</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AssetRetirementObligationRevisionOfEstimate_lbl" xml:lang="en-US" id="id_623015_571892_2_1">Revisions to estimates</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetRetirementObligationRevisionOfEstimate" xlink:to="us-gaap_AssetRetirementObligationRevisionOfEstimate_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_AssetRetirementObligationsLineItems" xlink:label="oas_AssetRetirementObligationsLineItems"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_AssetRetirementObligationsLineItems_lbl" xml:lang="en-US" id="id_623015_603094_3_1">Asset Retirement Obligations [Line Items]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_AssetRetirementObligationsLineItems_lbl" xml:lang="en-US" id="id_623015_603094_1_1">Asset Retirement Obligations [Line Items]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_AssetRetirementObligationsLineItems_lbl" xml:lang="en-US" id="id_623015_603094_2_1">Asset Retirement Obligations [Line Items]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_AssetRetirementObligationsLineItems" xlink:to="oas_AssetRetirementObligationsLineItems_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AssetRetirementObligationsNoncurrent" xlink:label="us-gaap_AssetRetirementObligationsNoncurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetRetirementObligationsNoncurrent_lbl" xml:lang="en-US" id="id_623015_578482_1_1">Asset Retirement Obligations Noncurrent</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AssetRetirementObligationsNoncurrent_lbl" xml:lang="en-US" id="id_623015_578482_2_1">Asset retirement obligations</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetRetirementObligationsNoncurrent" xlink:to="us-gaap_AssetRetirementObligationsNoncurrent_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_AssetRetirementObligationsTable" xlink:label="oas_AssetRetirementObligationsTable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_AssetRetirementObligationsTable_lbl" xml:lang="en-US" id="id_623015_605105_3_1">Asset Retirement Obligations [Table]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_AssetRetirementObligationsTable_lbl" xml:lang="en-US" id="id_623015_605105_1_1">Asset Retirement Obligations [Table]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_AssetRetirementObligationsTable_lbl" xml:lang="en-US" id="id_623015_605105_2_1">Asset Retirement Obligations [Table]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_AssetRetirementObligationsTable" xlink:to="oas_AssetRetirementObligationsTable_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_Assets" xlink:label="us-gaap_Assets"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_Assets_lbl" xml:lang="en-US" id="id_623015_569254_1_1">Assets</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_Assets_lbl" xml:lang="en-US" id="id_623015_569254_6_1">Total assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Assets" xlink:to="us-gaap_Assets_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AssetsAbstract" xlink:label="us-gaap_AssetsAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetsAbstract_lbl" xml:lang="en-US" id="id_623015_581095_1_1">Assets [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AssetsAbstract_lbl" xml:lang="en-US" id="id_623015_581095_2_1">ASSETS</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_AssetsAbstract_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AssetsCurrent" xlink:label="us-gaap_AssetsCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetsCurrent_lbl" xml:lang="en-US" id="id_623015_578885_1_1">Assets Current</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_AssetsCurrent_lbl" xml:lang="en-US" id="id_623015_578885_6_1">Total current assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsCurrent" xlink:to="us-gaap_AssetsCurrent_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AssetsFairValueDisclosure" xlink:label="us-gaap_AssetsFairValueDisclosure"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetsFairValueDisclosure_lbl" xml:lang="en-US" id="id_623015_569288_1_1">Assets Fair Value Disclosure</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AssetsFairValueDisclosure_lbl" xml:lang="en-US" id="id_623015_569288_2_1">Total assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsFairValueDisclosure" xlink:to="us-gaap_AssetsFairValueDisclosure_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_AssetsFairValueDisclosureAbstract" xlink:label="us-gaap_AssetsFairValueDisclosureAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AssetsFairValueDisclosureAbstract_lbl" xml:lang="en-US" id="id_623015_568523_1_1">Assets Fair Value Disclosure [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AssetsFairValueDisclosureAbstract_lbl" xml:lang="en-US" id="id_623015_568523_2_1">Assets:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsFairValueDisclosureAbstract" xlink:to="us-gaap_AssetsFairValueDisclosureAbstract_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_CapitalContributions" xlink:label="oas_CapitalContributions"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_CapitalContributions_lbl" xml:lang="en-US" id="id_623015_617657_3_1">Total capital contributions from the parent company. Includes long-term advances payable from the subsidiaries to the parent.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_CapitalContributions_lbl" xml:lang="en-US" id="id_623015_617657_1_1">Capital Contributions</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_CapitalContributions_lbl" xml:lang="en-US" id="id_623015_617657_2_1">Capital contributions from affiliates</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_CapitalContributions" xlink:to="oas_CapitalContributions_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_CapitalExpendituresIncurredButNotYetPaid" xlink:label="us-gaap_CapitalExpendituresIncurredButNotYetPaid"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CapitalExpendituresIncurredButNotYetPaid_lbl" xml:lang="en-US" id="id_623015_579422_1_1">Capital Expenditures Incurred But Not Yet Paid</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CapitalExpendituresIncurredButNotYetPaid_lbl" xml:lang="en-US" id="id_623015_579422_2_1">Change in accrued capital expenditures</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CapitalExpendituresIncurredButNotYetPaid" xlink:to="us-gaap_CapitalExpendituresIncurredButNotYetPaid_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_CapitalizedCostsAssetRetirementCosts" xlink:label="us-gaap_CapitalizedCostsAssetRetirementCosts"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CapitalizedCostsAssetRetirementCosts_lbl" xml:lang="en-US" id="id_623015_577689_1_1">Capitalized Costs Asset Retirement Costs</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CapitalizedCostsAssetRetirementCosts_lbl" xml:lang="en-US" id="id_623015_577689_2_1">Asset retirement costs</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CapitalizedCostsAssetRetirementCosts" xlink:to="us-gaap_CapitalizedCostsAssetRetirementCosts_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_CapitalizedCostsProvedProperties" xlink:label="us-gaap_CapitalizedCostsProvedProperties"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CapitalizedCostsProvedProperties_lbl" xml:lang="en-US" id="id_623015_570397_1_1">Capitalized Costs Proved Properties</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CapitalizedCostsProvedProperties_lbl" xml:lang="en-US" id="id_623015_570397_2_1">Capitalized interest</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CapitalizedCostsProvedProperties" xlink:to="us-gaap_CapitalizedCostsProvedProperties_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl" xml:lang="en-US" id="id_623015_569655_1_1">Cash And Cash Equivalents At Carrying Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl" xml:lang="en-US" id="id_623015_569655_4_1">Cash and cash equivalents at end of period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl" xml:lang="en-US" id="id_623015_569655_5_1">Cash and cash equivalents at beginning of period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl" xml:lang="en-US" id="id_623015_569655_2_1">Cash and cash equivalents</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValueAbstract" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValueAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValueAbstract_lbl" xml:lang="en-US" id="id_623015_579746_1_1">Cash And Cash Equivalents At Carrying Value [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValueAbstract_lbl" xml:lang="en-US" id="id_623015_579746_2_1">Cash and cash equivalents:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsAtCarryingValueAbstract" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValueAbstract_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:label="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_lbl" xml:lang="en-US" id="id_623015_570920_1_1">Cash And Cash Equivalents Period Increase Decrease</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_lbl" xml:lang="en-US" id="id_623015_570920_2_1">Decrease in cash and cash equivalents</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_lbl" xml:lang="en-US" id="id_623015_570920_6_1">Increase (decrease) in cash and cash equivalents</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:to="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract" xlink:label="us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract_lbl" xml:lang="en-US" id="id_623015_572539_1_1">Cash Flow Noncash Investing And Financing Activities Disclosure [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract_lbl" xml:lang="en-US" id="id_623015_572539_2_1">Supplemental non-cash transactions:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract" xlink:to="us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_ChangeInAssetRetirementObligationLineItems" xlink:label="oas_ChangeInAssetRetirementObligationLineItems"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_ChangeInAssetRetirementObligationLineItems_lbl" xml:lang="en-US" id="id_623015_700471_3_1">Change In Asset Retirement Obligation [Line Items]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_ChangeInAssetRetirementObligationLineItems_lbl" xml:lang="en-US" id="id_623015_700471_1_1">Change In Asset Retirement Obligation [Line Items]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_ChangeInAssetRetirementObligationLineItems_lbl" xml:lang="en-US" id="id_623015_700471_2_1">Change In Asset Retirement Obligation [Line Items]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_ChangeInAssetRetirementObligationLineItems" xlink:to="oas_ChangeInAssetRetirementObligationLineItems_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_CommitmentsAndContingencies" xlink:label="us-gaap_CommitmentsAndContingencies"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommitmentsAndContingencies_lbl" xml:lang="en-US" id="id_623015_577863_1_1">Commitments And Contingencies</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CommitmentsAndContingencies_lbl" xml:lang="en-US" id="id_623015_577863_2_1">Commitments and contingencies (Note 12)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommitmentsAndContingencies" xlink:to="us-gaap_CommitmentsAndContingencies_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_lbl" xml:lang="en-US" id="id_623015_578699_1_1">Commitments And Contingencies Disclosure [Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_lbl" xml:lang="en-US" id="id_623015_578699_2_1">Commitments and Contingencies</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:to="us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_CommodityContractMember" xlink:label="us-gaap_CommodityContractMember"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CommodityContractMember_lbl" xml:lang="en-US" id="id_623015_573672_2_1">Commodity Derivative Instruments [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommodityContractMember" xlink:to="us-gaap_CommodityContractMember_lbl"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockMember_lbl" xml:lang="en-US" id="id_623015_565727_1_1">Common Stock [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CommonStockMember_lbl" xml:lang="en-US" id="id_623015_565727_2_1">Common Stock [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockMember" xlink:to="us-gaap_CommonStockMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare_lbl" xml:lang="en-US" id="id_623015_580157_1_1">Common Stock Par Or Stated Value Per Share</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare_lbl" xml:lang="en-US" id="id_623015_580157_2_1">Common stock, par value</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockParOrStatedValuePerShare" xlink:to="us-gaap_CommonStockParOrStatedValuePerShare_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_CommonStockSharesAuthorized" xlink:label="us-gaap_CommonStockSharesAuthorized"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockSharesAuthorized_lbl" xml:lang="en-US" id="id_623015_566386_1_1">Common Stock Shares Authorized</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CommonStockSharesAuthorized_lbl" xml:lang="en-US" id="id_623015_566386_2_1">Common stock, shares authorized</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesAuthorized" xlink:to="us-gaap_CommonStockSharesAuthorized_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_CommonStockSharesIssued" xlink:label="us-gaap_CommonStockSharesIssued"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockSharesIssued_lbl" xml:lang="en-US" id="id_623015_572997_1_1">Common Stock Shares Issued</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CommonStockSharesIssued_lbl" xml:lang="en-US" id="id_623015_572997_2_1">Common stock, shares issued</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesIssued" xlink:to="us-gaap_CommonStockSharesIssued_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="us-gaap_CommonStockSharesOutstanding"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xml:lang="en-US" id="id_623015_577982_1_1">Common Stock Shares Outstanding</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xml:lang="en-US" id="id_623015_577982_2_1">Common stock, shares outstanding</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesOutstanding" xlink:to="us-gaap_CommonStockSharesOutstanding_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_CommonStockValue" xlink:label="us-gaap_CommonStockValue"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockValue_lbl" xml:lang="en-US" id="id_623015_573386_1_1">Common Stock Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CommonStockValue_lbl" xml:lang="en-US" id="id_623015_573386_2_1">Common stock, $0.01 par value; 300,000,000 shares authorized; 93,435,593 issued and 93,369,468 outstanding at September 30, 2012; 92,483,393 issued and 92,460,914 outstanding at December 31, 2011</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockValue" xlink:to="us-gaap_CommonStockValue_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_CommonStockValueOutstanding" xlink:label="us-gaap_CommonStockValueOutstanding"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CommonStockValueOutstanding_lbl" xml:lang="en-US" id="id_623015_578243_1_1">Common Stock Value Outstanding</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CommonStockValueOutstanding_lbl" xml:lang="en-US" id="id_623015_578243_2_1">Common stock, $0.01 par value; 300,000,000 shares authorized; 92,483,393 issued and 92,460,914 outstanding</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockValueOutstanding" xlink:to="us-gaap_CommonStockValueOutstanding_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_CondensedFinancialInformationOfParentCompanyOnlyDisclosureTextBlock" xlink:label="us-gaap_CondensedFinancialInformationOfParentCompanyOnlyDisclosureTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CondensedFinancialInformationOfParentCompanyOnlyDisclosureTextBlock_lbl" xml:lang="en-US" id="id_623015_582057_1_1">Condensed Financial Information Of Parent Company Only Disclosure [Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CondensedFinancialInformationOfParentCompanyOnlyDisclosureTextBlock_lbl" xml:lang="en-US" id="id_623015_582057_2_1">Condensed Consolidating Financial Information</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CondensedFinancialInformationOfParentCompanyOnlyDisclosureTextBlock" xlink:to="us-gaap_CondensedFinancialInformationOfParentCompanyOnlyDisclosureTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_CondensedFinancialStatementsCaptionsLineItems" xlink:label="us-gaap_CondensedFinancialStatementsCaptionsLineItems"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CondensedFinancialStatementsCaptionsLineItems_lbl" xml:lang="en-US" id="id_623015_575264_1_1">Condensed Financial Statements Captions [Line Items]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CondensedFinancialStatementsCaptionsLineItems_lbl" xml:lang="en-US" id="id_623015_575264_2_1">Condensed Financial Statements, Captions [Line Items]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CondensedFinancialStatementsCaptionsLineItems" xlink:to="us-gaap_CondensedFinancialStatementsCaptionsLineItems_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ConsolidationEliminationsMember" xlink:label="us-gaap_ConsolidationEliminationsMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConsolidationEliminationsMember_lbl" xml:lang="en-US" id="id_623015_574643_1_1">Consolidation Eliminations [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ConsolidationEliminationsMember_lbl" xml:lang="en-US" id="id_623015_574643_2_1">Intercompany Eliminations [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConsolidationEliminationsMember" xlink:to="us-gaap_ConsolidationEliminationsMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ConsolidationPolicyTextBlock" xlink:label="us-gaap_ConsolidationPolicyTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConsolidationPolicyTextBlock_lbl" xml:lang="en-US" id="id_623015_569664_1_1">Consolidation Policy [Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ConsolidationPolicyTextBlock_lbl" xml:lang="en-US" id="id_623015_569664_2_1">Basis of Presentation</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConsolidationPolicyTextBlock" xlink:to="us-gaap_ConsolidationPolicyTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_CostsAndExpenses" xlink:label="us-gaap_CostsAndExpenses"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CostsAndExpenses_lbl" xml:lang="en-US" id="id_623015_573816_1_1">Costs And Expenses</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CostsAndExpenses_lbl" xml:lang="en-US" id="id_623015_573816_2_1">Total expenses</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_CostsAndExpenses_lbl" xml:lang="en-US" id="id_623015_573816_6_1">Total expenses</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CostsAndExpenses" xlink:to="us-gaap_CostsAndExpenses_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_CostsAndExpensesAbstract" xlink:label="us-gaap_CostsAndExpensesAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CostsAndExpensesAbstract_lbl" xml:lang="en-US" id="id_623015_570196_1_1">Costs And Expenses [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CostsAndExpensesAbstract_lbl" xml:lang="en-US" id="id_623015_570196_2_1">Expenses</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CostsAndExpensesAbstract" xlink:to="us-gaap_CostsAndExpensesAbstract_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_CrudeOilMember" xlink:label="us-gaap_CrudeOilMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CrudeOilMember_lbl" xml:lang="en-US" id="id_623015_571402_1_1">Crude Oil [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CrudeOilMember_lbl" xml:lang="en-US" id="id_623015_571402_2_1">Crude Oil Collar [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CrudeOilMember" xlink:to="us-gaap_CrudeOilMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2012/dei-2012-01-31.xsd#dei_CurrentFiscalYearEndDate" xlink:label="dei_CurrentFiscalYearEndDate"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_CurrentFiscalYearEndDate_lbl" xml:lang="en-US" id="id_623015_565178_1_1">Current Fiscal Year End Date</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="dei_CurrentFiscalYearEndDate_lbl" xml:lang="en-US" id="id_623015_565178_2_1">Current Fiscal Year End Date</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_CurrentFiscalYearEndDate" xlink:to="dei_CurrentFiscalYearEndDate_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_CurrentRatioMember" xlink:label="oas_CurrentRatioMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_CurrentRatioMember_lbl" xml:lang="en-US" id="id_623015_615510_3_1">Current Ratio [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_CurrentRatioMember_lbl" xml:lang="en-US" id="id_623015_615510_1_1">Current Ratio [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_CurrentRatioMember_lbl" xml:lang="en-US" id="id_623015_615510_2_1">Current Ratio [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_CurrentRatioMember" xlink:to="oas_CurrentRatioMember_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_DebtDisclosureLineItems" xlink:label="oas_DebtDisclosureLineItems"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_DebtDisclosureLineItems_lbl" xml:lang="en-US" id="id_623015_614293_3_1">Debt Disclosure [Line Items]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_DebtDisclosureLineItems_lbl" xml:lang="en-US" id="id_623015_614293_1_1">Debt Disclosure [Line Items]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_DebtDisclosureLineItems_lbl" xml:lang="en-US" id="id_623015_614293_2_1">Debt Disclosure [Line Items]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_DebtDisclosureLineItems" xlink:to="oas_DebtDisclosureLineItems_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_DebtDisclosureTable" xlink:label="oas_DebtDisclosureTable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_DebtDisclosureTable_lbl" xml:lang="en-US" id="id_623015_616530_3_1">Debt Disclosure [Table]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_DebtDisclosureTable_lbl" xml:lang="en-US" id="id_623015_616530_1_1">Debt Disclosure [Table]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_DebtDisclosureTable_lbl" xml:lang="en-US" id="id_623015_616530_2_1">Debt Disclosure [Table]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_DebtDisclosureTable" xlink:to="oas_DebtDisclosureTable_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_DebtDiscountAmortizationAndOther" xlink:label="oas_DebtDiscountAmortizationAndOther"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_DebtDiscountAmortizationAndOther_lbl" xml:lang="en-US" id="id_623015_617946_3_1">The total of the component of interest expense representing the noncash expenses charged against earnings in the period to amortize the long-term deferred financing costs and other income (expense) included in net income that results in no cash inflows or outflows in the period. Includes noncash adjustments to reconcile net income (loss) to cash provided by (used in) operating activities that are not separately disclosed.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_DebtDiscountAmortizationAndOther_lbl" xml:lang="en-US" id="id_623015_617946_1_1">Debt Discount Amortization And Other</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_DebtDiscountAmortizationAndOther_lbl" xml:lang="en-US" id="id_623015_617946_2_1">Debt discount amortization and other</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_DebtDiscountAmortizationAndOther" xlink:to="oas_DebtDiscountAmortizationAndOther_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="us-gaap_DebtInstrumentAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentAxis_lbl" xml:lang="en-US" id="id_623015_568852_1_1">Debt Instrument [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentAxis_lbl" xml:lang="en-US" id="id_623015_568852_2_1">Debt Instrument [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentAxis" xlink:to="us-gaap_DebtInstrumentAxis_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_DebtInstrumentFaceAmount" xlink:label="us-gaap_DebtInstrumentFaceAmount"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentFaceAmount_lbl" xml:lang="en-US" id="id_623015_568562_1_1">Debt Instrument Face Amount</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentFaceAmount_lbl" xml:lang="en-US" id="id_623015_568562_2_1">Senior unsecured debt principal amount</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentFaceAmount" xlink:to="us-gaap_DebtInstrumentFaceAmount_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_DebtInstrumentFrequencyOfPeriodicPayment" xlink:label="us-gaap_DebtInstrumentFrequencyOfPeriodicPayment"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentFrequencyOfPeriodicPayment_lbl" xml:lang="en-US" id="id_623015_568015_1_1">Debt Instrument Frequency Of Periodic Payment</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentFrequencyOfPeriodicPayment_lbl" xml:lang="en-US" id="id_623015_568015_2_1">Senior unsecured notes payment frequency</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentFrequencyOfPeriodicPayment" xlink:to="us-gaap_DebtInstrumentFrequencyOfPeriodicPayment_lbl"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage_lbl" xml:lang="en-US" id="id_623015_574119_1_1">Debt Instrument Interest Rate Stated Percentage</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage_lbl" xml:lang="en-US" id="id_623015_574119_2_1">Senior unsecured notes stated interest rate</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:to="us-gaap_DebtInstrumentInterestRateStatedPercentage_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="us-gaap_DebtInstrumentLineItems"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentLineItems_lbl" xml:lang="en-US" id="id_623015_575059_1_1">Debt Instrument [Line Items]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentLineItems_lbl" xml:lang="en-US" id="id_623015_575059_2_1">Debt Instrument [Line Items]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentLineItems_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_DebtInstrumentMaturityDate" xlink:label="us-gaap_DebtInstrumentMaturityDate"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentMaturityDate_lbl" xml:lang="en-US" id="id_623015_568755_1_1">Debt Instrument Maturity Date</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentMaturityDate_lbl" xml:lang="en-US" id="id_623015_568755_2_1">Debt instrument, maturity date</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentMaturityDate" xlink:to="us-gaap_DebtInstrumentMaturityDate_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="us-gaap_DebtInstrumentNameDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentNameDomain_lbl" xml:lang="en-US" id="id_623015_579268_1_1">Debt Instrument Name [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentNameDomain_lbl" xml:lang="en-US" id="id_623015_579268_2_1">Debt Instrument, Name [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentNameDomain" xlink:to="us-gaap_DebtInstrumentNameDomain_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="us-gaap_DebtInstrumentTable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentTable_lbl" xml:lang="en-US" id="id_623015_573776_1_1">Debt Instrument [Table]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentTable_lbl" xml:lang="en-US" id="id_623015_573776_2_1">Schedule of Long-term Debt Instruments [Table]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_DebtInstrumentTable_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount" xlink:label="us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount_lbl" xml:lang="en-US" id="id_623015_581210_1_1">Debt Instrument Unused Borrowing Capacity Amount</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount_lbl" xml:lang="en-US" id="id_623015_581210_2_1">Letter of credit unused borrowing base capacity</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount" xlink:to="us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_DebtRatioAxis" xlink:label="oas_DebtRatioAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_DebtRatioAxis_lbl" xml:lang="en-US" id="id_623015_614571_3_1">Debt Ratio [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_DebtRatioAxis_lbl" xml:lang="en-US" id="id_623015_614571_1_1">Debt Ratio [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_DebtRatioAxis_lbl" xml:lang="en-US" id="id_623015_614571_2_1">Debt Ratio [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_DebtRatioAxis" xlink:to="oas_DebtRatioAxis_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_DebtRatioDomain" xlink:label="oas_DebtRatioDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_DebtRatioDomain_lbl" xml:lang="en-US" id="id_623015_615513_3_1">Debt Ratio [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_DebtRatioDomain_lbl" xml:lang="en-US" id="id_623015_615513_1_1">Debt Ratio [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_DebtRatioDomain_lbl" xml:lang="en-US" id="id_623015_615513_2_1">Debt Ratio [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_DebtRatioDomain" xlink:to="oas_DebtRatioDomain_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_DeferredCostsAndOtherAssets" xlink:label="us-gaap_DeferredCostsAndOtherAssets"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredCostsAndOtherAssets_lbl" xml:lang="en-US" id="id_623015_573293_1_1">Deferred Costs And Other Assets</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DeferredCostsAndOtherAssets_lbl" xml:lang="en-US" id="id_623015_573293_2_1">Deferred costs and other assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredCostsAndOtherAssets" xlink:to="us-gaap_DeferredCostsAndOtherAssets_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_DeferredFinanceCostsNet" xlink:label="us-gaap_DeferredFinanceCostsNet"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredFinanceCostsNet_lbl" xml:lang="en-US" id="id_623015_566899_1_1">Deferred Finance Costs Net</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DeferredFinanceCostsNet_lbl" xml:lang="en-US" id="id_623015_566899_2_1">Deferred financing costs</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredFinanceCostsNet" xlink:to="us-gaap_DeferredFinanceCostsNet_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefit"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefit_lbl" xml:lang="en-US" id="id_623015_573468_1_1">Deferred Income Tax Expense Benefit</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefit_lbl" xml:lang="en-US" id="id_623015_573468_2_1">Deferred income taxes</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:to="us-gaap_DeferredIncomeTaxExpenseBenefit_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_DeferredTaxAssetsNetCurrent" xlink:label="us-gaap_DeferredTaxAssetsNetCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredTaxAssetsNetCurrent_lbl" xml:lang="en-US" id="id_623015_575663_1_1">Deferred Tax Assets Net Current</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DeferredTaxAssetsNetCurrent_lbl" xml:lang="en-US" id="id_623015_575663_2_1">Deferred income taxes</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsNetCurrent" xlink:to="us-gaap_DeferredTaxAssetsNetCurrent_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_DeferredTaxAssetsNetNoncurrent" xlink:label="us-gaap_DeferredTaxAssetsNetNoncurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredTaxAssetsNetNoncurrent_lbl" xml:lang="en-US" id="id_623015_569156_1_1">Deferred Tax Assets Net Noncurrent</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DeferredTaxAssetsNetNoncurrent_lbl" xml:lang="en-US" id="id_623015_569156_2_1">Deferred income taxes</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsNetNoncurrent" xlink:to="us-gaap_DeferredTaxAssetsNetNoncurrent_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_DeferredTaxLiabilitiesCurrent" xlink:label="us-gaap_DeferredTaxLiabilitiesCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredTaxLiabilitiesCurrent_lbl" xml:lang="en-US" id="id_623015_565650_1_1">Deferred Tax Liabilities Current</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DeferredTaxLiabilitiesCurrent_lbl" xml:lang="en-US" id="id_623015_565650_2_1">Deferred income taxes</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxLiabilitiesCurrent" xlink:to="us-gaap_DeferredTaxLiabilitiesCurrent_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_DeferredTaxLiabilitiesNoncurrent" xlink:label="us-gaap_DeferredTaxLiabilitiesNoncurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredTaxLiabilitiesNoncurrent_lbl" xml:lang="en-US" id="id_623015_572782_1_1">Deferred Tax Liabilities Noncurrent</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DeferredTaxLiabilitiesNoncurrent_lbl" xml:lang="en-US" id="id_623015_572782_2_1">Deferred income taxes</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxLiabilitiesNoncurrent" xlink:to="us-gaap_DeferredTaxLiabilitiesNoncurrent_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_DepreciationDepletionAndAmortization" xlink:label="us-gaap_DepreciationDepletionAndAmortization"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DepreciationDepletionAndAmortization_lbl" xml:lang="en-US" id="id_623015_565916_1_1">Depreciation Depletion And Amortization</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DepreciationDepletionAndAmortization_lbl" xml:lang="en-US" id="id_623015_565916_2_1">Depreciation, depletion and amortization</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DepreciationDepletionAndAmortization" xlink:to="us-gaap_DepreciationDepletionAndAmortization_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_DerivativeAssetsCurrent" xlink:label="us-gaap_DerivativeAssetsCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DerivativeAssetsCurrent_lbl" xml:lang="en-US" id="id_623015_568124_1_1">Derivative Assets Current</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DerivativeAssetsCurrent_lbl" xml:lang="en-US" id="id_623015_568124_2_1">Derivative instruments</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DerivativeAssetsCurrent_lbl" xml:lang="en-US" id="id_623015_568124_12_1">Derivative instruments -current assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeAssetsCurrent" xlink:to="us-gaap_DerivativeAssetsCurrent_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_DerivativeAssetsNoncurrent" xlink:label="us-gaap_DerivativeAssetsNoncurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DerivativeAssetsNoncurrent_lbl" xml:lang="en-US" id="id_623015_574343_1_1">Derivative Assets Noncurrent</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DerivativeAssetsNoncurrent_lbl" xml:lang="en-US" id="id_623015_574343_2_1">Derivative instruments</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_DerivativeAssetsNoncurrent_lbl" xml:lang="en-US" id="id_623015_574343_12_1">Derivative instruments - non-current assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeAssetsNoncurrent" xlink:to="us-gaap_DerivativeAssetsNoncurrent_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_DerivativeAverageCapPrice" xlink:label="us-gaap_DerivativeAverageCapPrice"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DerivativeAverageCapPrice_lbl" xml:lang="en-US" id="id_623015_574251_1_1">Derivative Average Cap Price</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DerivativeAverageCapPrice_lbl" xml:lang="en-US" id="id_623015_574251_2_1">Average Ceiling Price</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeAverageCapPrice" xlink:to="us-gaap_DerivativeAverageCapPrice_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_DerivativeAverageFloorPrice" xlink:label="us-gaap_DerivativeAverageFloorPrice"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DerivativeAverageFloorPrice_lbl" xml:lang="en-US" id="id_623015_575581_1_1">Derivative Average Floor Price</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DerivativeAverageFloorPrice_lbl" xml:lang="en-US" id="id_623015_575581_2_1">Average Floor Price</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeAverageFloorPrice" xlink:to="us-gaap_DerivativeAverageFloorPrice_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_DerivativeAverageSubFloorPrice" xlink:label="oas_DerivativeAverageSubFloorPrice"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_DerivativeAverageSubFloorPrice_lbl" xml:lang="en-US" id="id_623015_614489_3_1">The average strike price of the sold put that establishes the price at which if the market price falls below, the minimum price would be index price plus the difference between the purchased put (floor) and the sold put strike price.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_DerivativeAverageSubFloorPrice_lbl" xml:lang="en-US" id="id_623015_614489_1_1">Derivative Average Sub Floor Price</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_DerivativeAverageSubFloorPrice_lbl" xml:lang="en-US" id="id_623015_614489_2_1">Average Sub-Floor Price</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_DerivativeAverageSubFloorPrice" xlink:to="oas_DerivativeAverageSubFloorPrice_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_DerivativeCreditRiskValuationAdjustmentDerivativeLiabilities" xlink:label="us-gaap_DerivativeCreditRiskValuationAdjustmentDerivativeLiabilities"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DerivativeCreditRiskValuationAdjustmentDerivativeLiabilities_lbl" xml:lang="en-US" id="id_623015_572337_1_1">Derivative Credit Risk Valuation Adjustment Derivative Liabilities</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DerivativeCreditRiskValuationAdjustmentDerivativeLiabilities_lbl" xml:lang="en-US" id="id_623015_572337_2_1">Derivative liability, net</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeCreditRiskValuationAdjustmentDerivativeLiabilities" xlink:to="us-gaap_DerivativeCreditRiskValuationAdjustmentDerivativeLiabilities_lbl"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_EarningsBeforeIncomeTaxDepreciationAndAmortizationOfExtraordinaryItemsMember_lbl" xml:lang="en-US" id="id_623015_615394_3_1">Earnings Before Income Tax Depreciation And Amortization of Extraordinary Items [Member]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_lbl" xml:lang="en-US" id="id_623015_579535_2_1">Unrecognized expense of outstanding PSUs</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2012/dei-2012-01-31.xsd#dei_EntityCentralIndexKey" xlink:label="dei_EntityCentralIndexKey"/>
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    <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2012/dei-2012-01-31.xsd#dei_EntityCommonStockSharesOutstanding" xlink:label="dei_EntityCommonStockSharesOutstanding"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_EntityCommonStockSharesOutstanding_lbl" xml:lang="en-US" id="id_623015_565125_1_1">Entity Common Stock Shares Outstanding</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_lbl" xml:lang="en-US" id="id_623015_577859_1_1">Increase Decrease In Accounts Payable And Accrued Liabilities</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_lbl" xml:lang="en-US" id="id_623015_577859_2_1">Change in accounts payable and accrued liabilities</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:label="us-gaap_IncreaseDecreaseInAccountsReceivable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IncreaseDecreaseInAccountsReceivable_lbl" xml:lang="en-US" id="id_623015_569152_1_1">Increase Decrease In Accounts Receivable</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract"/>
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    <label xlink:type="resource" xlink:role="http://xbrl.us/us-gaap/role/label/negated" xlink:label="us-gaap_IncreaseDecreaseInOtherCurrentAssets_lbl" xml:lang="en-US" id="id_623015_581500_8_1">Change in other current assets</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingAssets"/>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestExpense" xlink:to="us-gaap_InterestExpense_lbl"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InterestPayableCurrent_lbl" xml:lang="en-US" id="id_623015_578788_2_1">Accrued interest payable</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InventoryDisclosureTextBlock_lbl" xml:lang="en-US" id="id_623015_569868_2_1">Inventory</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryDisclosureTextBlock" xlink:to="us-gaap_InventoryDisclosureTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_InventoryNet" xlink:label="us-gaap_InventoryNet"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryNet_lbl" xml:lang="en-US" id="id_623015_571361_1_1">Inventory Net</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InventoryNet_lbl" xml:lang="en-US" id="id_623015_571361_2_1">Inventory</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_InventoryNet_lbl" xml:lang="en-US" id="id_623015_571361_6_1">Total inventory</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryNet" xlink:to="us-gaap_InventoryNet_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_InvestmentsInAndAdvancesToAffiliates" xlink:label="oas_InvestmentsInAndAdvancesToAffiliates"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_InvestmentsInAndAdvancesToAffiliates_lbl" xml:lang="en-US" id="id_623015_617379_3_1">Investment in common stock of, contributed capital to, equity in cumulative net income and loss of, and net intercompany advances to/from consolidated subsidiaries.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_InvestmentsInAndAdvancesToAffiliates_lbl" xml:lang="en-US" id="id_623015_617379_1_1">Investments In And Advances To Affiliates</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_InvestmentsInAndAdvancesToAffiliates_lbl" xml:lang="en-US" id="id_623015_617379_2_1">Investments in and advances to subsidiaries</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_InvestmentsInAndAdvancesToAffiliates" xlink:to="oas_InvestmentsInAndAdvancesToAffiliates_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_LeaseOperatingExpense" xlink:label="us-gaap_LeaseOperatingExpense"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LeaseOperatingExpense_lbl" xml:lang="en-US" id="id_623015_577518_1_1">Lease Operating Expense</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LeaseOperatingExpense_lbl" xml:lang="en-US" id="id_623015_577518_2_1">Lease operating expenses</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LeaseOperatingExpense" xlink:to="us-gaap_LeaseOperatingExpense_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2012/dei-2012-01-31.xsd#dei_LegalEntityAxis" xlink:label="dei_LegalEntityAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_LegalEntityAxis_lbl" xml:lang="en-US" id="id_623015_565220_1_1">Legal Entity [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="dei_LegalEntityAxis_lbl" xml:lang="en-US" id="id_623015_565220_2_1">Legal Entity [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_LegalEntityAxis" xlink:to="dei_LegalEntityAxis_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_LessThanPointTwoFiveToOneMember" xlink:label="oas_LessThanPointTwoFiveToOneMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_LessThanPointTwoFiveToOneMember_lbl" xml:lang="en-US" id="id_623015_614718_3_1">Less Than Point Two Five To One [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_LessThanPointTwoFiveToOneMember_lbl" xml:lang="en-US" id="id_623015_614718_1_1">Less Than Point Two Five To One [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_LessThanPointTwoFiveToOneMember_lbl" xml:lang="en-US" id="id_623015_614718_2_1">Less Than .25 To 1 [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_LessThanPointTwoFiveToOneMember" xlink:to="oas_LessThanPointTwoFiveToOneMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_Liabilities" xlink:label="us-gaap_Liabilities"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_Liabilities_lbl" xml:lang="en-US" id="id_623015_574733_1_1">Liabilities</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_Liabilities_lbl" xml:lang="en-US" id="id_623015_574733_2_1">Total liabilities</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_Liabilities_lbl" xml:lang="en-US" id="id_623015_574733_6_1">Total liabilities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Liabilities" xlink:to="us-gaap_Liabilities_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_lbl" xml:lang="en-US" id="id_623015_572914_1_1">Liabilities And Stockholders Equity</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_lbl" xml:lang="en-US" id="id_623015_572914_2_1">Total liabilities and stockholders' equity</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_lbl" xml:lang="en-US" id="id_623015_572914_6_1">Total liabilities and stockholders' equity</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_LiabilitiesAndStockholdersEquity_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract_lbl" xml:lang="en-US" id="id_623015_574179_1_1">Liabilities And Stockholders Equity [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract_lbl" xml:lang="en-US" id="id_623015_574179_2_1">LIABILITIES AND STOCKHOLDERS' EQUITY</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="us-gaap_LiabilitiesAndStockholdersEquityAbstract_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:label="us-gaap_LiabilitiesCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesCurrent_lbl" xml:lang="en-US" id="id_623015_568115_1_1">Liabilities Current</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_LiabilitiesCurrent_lbl" xml:lang="en-US" id="id_623015_568115_6_1">Total current liabilities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesCurrent" xlink:to="us-gaap_LiabilitiesCurrent_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_LiabilitiesFairValueDisclosure" xlink:label="us-gaap_LiabilitiesFairValueDisclosure"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesFairValueDisclosure_lbl" xml:lang="en-US" id="id_623015_578152_1_1">Liabilities Fair Value Disclosure</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LiabilitiesFairValueDisclosure_lbl" xml:lang="en-US" id="id_623015_578152_2_1">Total liabilities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesFairValueDisclosure" xlink:to="us-gaap_LiabilitiesFairValueDisclosure_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_LiabilitiesFairValueDisclosureAbstract" xlink:label="us-gaap_LiabilitiesFairValueDisclosureAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesFairValueDisclosureAbstract_lbl" xml:lang="en-US" id="id_623015_582118_1_1">Liabilities Fair Value Disclosure [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LiabilitiesFairValueDisclosureAbstract_lbl" xml:lang="en-US" id="id_623015_582118_2_1">Liabilities:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesFairValueDisclosureAbstract" xlink:to="us-gaap_LiabilitiesFairValueDisclosureAbstract_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_LiborMember" xlink:label="oas_LiborMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_LiborMember_lbl" xml:lang="en-US" id="id_623015_590994_3_1">LIBOR [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_LiborMember_lbl" xml:lang="en-US" id="id_623015_590994_1_1">Libor [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_LiborMember_lbl" xml:lang="en-US" id="id_623015_590994_2_1">LIBOR [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_LiborMember" xlink:to="oas_LiborMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_LineOfCreditFacilityInterestRateDuringPeriod" xlink:label="us-gaap_LineOfCreditFacilityInterestRateDuringPeriod"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityInterestRateDuringPeriod_lbl" xml:lang="en-US" id="id_623015_566021_1_1">Line Of Credit Facility Interest Rate During Period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LineOfCreditFacilityInterestRateDuringPeriod_lbl" xml:lang="en-US" id="id_623015_566021_2_1">Debt instrument interest rate terms, in percentage</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityInterestRateDuringPeriod" xlink:to="us-gaap_LineOfCreditFacilityInterestRateDuringPeriod_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_lbl" xml:lang="en-US" id="id_623015_571182_1_1">Line Of Credit Facility Maximum Borrowing Capacity</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_lbl" xml:lang="en-US" id="id_623015_571182_2_1">Letters of credit borrowings</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:to="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_LineOfCreditFacilityMaximumIncreaseToAggregateCommitments" xlink:label="oas_LineOfCreditFacilityMaximumIncreaseToAggregateCommitments"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_LineOfCreditFacilityMaximumIncreaseToAggregateCommitments_lbl" xml:lang="en-US" id="id_623015_662280_3_1">The aggregate commitment may be increased to this amount by increasing the commitment of one or more lender(s) under the credit facility.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_LineOfCreditFacilityMaximumIncreaseToAggregateCommitments_lbl" xml:lang="en-US" id="id_623015_662280_1_1">Line Of Credit Facility Maximum Increase To Aggregate Commitments</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_LineOfCreditFacilityMaximumIncreaseToAggregateCommitments_lbl" xml:lang="en-US" id="id_623015_662280_2_1">Increase in aggregate commitment</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_LineOfCreditFacilityMaximumIncreaseToAggregateCommitments" xlink:to="oas_LineOfCreditFacilityMaximumIncreaseToAggregateCommitments_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage" xlink:label="us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage_lbl" xml:lang="en-US" id="id_623015_582323_1_1">Line Of Credit Facility Unused Capacity Commitment Fee Percentage</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage_lbl" xml:lang="en-US" id="id_623015_582323_2_1">Commitment fee of borrowing base capacity not utilized</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage" xlink:to="us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_LineOfCreditMember" xlink:label="us-gaap_LineOfCreditMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditMember_lbl" xml:lang="en-US" id="id_623015_569312_1_1">Line Of Credit [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LineOfCreditMember_lbl" xml:lang="en-US" id="id_623015_569312_2_1">Line of Credit [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditMember" xlink:to="us-gaap_LineOfCreditMember_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_LongTermCommitmentAxis" xlink:label="oas_LongTermCommitmentAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_LongTermCommitmentAxis_lbl" xml:lang="en-US" id="id_623015_614614_3_1">Long Term Commitment [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_LongTermCommitmentAxis_lbl" xml:lang="en-US" id="id_623015_614614_1_1">Long Term Commitment [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_LongTermCommitmentAxis_lbl" xml:lang="en-US" id="id_623015_614614_2_1">Long Term Commitment [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_LongTermCommitmentAxis" xlink:to="oas_LongTermCommitmentAxis_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_LongTermCommitmentDomain" xlink:label="oas_LongTermCommitmentDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_LongTermCommitmentDomain_lbl" xml:lang="en-US" id="id_623015_614634_3_1">Long Term Commitment [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_LongTermCommitmentDomain_lbl" xml:lang="en-US" id="id_623015_614634_1_1">Long Term Commitment [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_LongTermCommitmentDomain_lbl" xml:lang="en-US" id="id_623015_614634_2_1">Long Term Commitment [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_LongTermCommitmentDomain" xlink:to="oas_LongTermCommitmentDomain_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_LongTermCommitmentsMember" xlink:label="oas_LongTermCommitmentsMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_LongTermCommitmentsMember_lbl" xml:lang="en-US" id="id_623015_614635_3_1">Long Term Commitments [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_LongTermCommitmentsMember_lbl" xml:lang="en-US" id="id_623015_614635_1_1">Long Term Commitments [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_LongTermCommitmentsMember_lbl" xml:lang="en-US" id="id_623015_614635_2_1">Long Term Commitments [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_LongTermCommitmentsMember" xlink:to="oas_LongTermCommitmentsMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_LongTermDebtFairValue" xlink:label="us-gaap_LongTermDebtFairValue"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtFairValue_lbl" xml:lang="en-US" id="id_623015_566934_1_1">Long Term Debt Fair Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtFairValue_lbl" xml:lang="en-US" id="id_623015_566934_2_1">Long-term debt, fair value</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtFairValue" xlink:to="us-gaap_LongTermDebtFairValue_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_LongTermDebtNoncurrent" xlink:label="us-gaap_LongTermDebtNoncurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtNoncurrent_lbl" xml:lang="en-US" id="id_623015_580651_1_1">Long Term Debt Noncurrent</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtNoncurrent_lbl" xml:lang="en-US" id="id_623015_580651_2_1">Long-term debt</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtNoncurrent" xlink:to="us-gaap_LongTermDebtNoncurrent_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_LongTermDebtTextBlock" xlink:label="us-gaap_LongTermDebtTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtTextBlock_lbl" xml:lang="en-US" id="id_623015_580667_1_1">Long Term Debt [Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtTextBlock_lbl" xml:lang="en-US" id="id_623015_580667_2_1">Long-Term Debt</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtTextBlock" xlink:to="us-gaap_LongTermDebtTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="us-gaap_LongtermDebtTypeAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongtermDebtTypeAxis_lbl" xml:lang="en-US" id="id_623015_579415_1_1">Longterm Debt Type [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongtermDebtTypeAxis_lbl" xml:lang="en-US" id="id_623015_579415_2_1">Long-term Debt, Type [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongtermDebtTypeAxis" xlink:to="us-gaap_LongtermDebtTypeAxis_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="us-gaap_LongtermDebtTypeDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongtermDebtTypeDomain_lbl" xml:lang="en-US" id="id_623015_573322_1_1">Longterm Debt Type [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongtermDebtTypeDomain_lbl" xml:lang="en-US" id="id_623015_573322_2_1">Long-term Debt, Type [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongtermDebtTypeDomain" xlink:to="us-gaap_LongtermDebtTypeDomain_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_LossOnContractTermination" xlink:label="us-gaap_LossOnContractTermination"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LossOnContractTermination_lbl" xml:lang="en-US" id="id_623015_580000_1_1">Loss On Contract Termination</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LossOnContractTermination_lbl" xml:lang="en-US" id="id_623015_580000_2_1">Payments upon early contract termination</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LossOnContractTermination" xlink:to="us-gaap_LossOnContractTermination_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis" xlink:label="us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_lbl" xml:lang="en-US" id="id_623015_581369_1_1">Major Types Of Debt And Equity Securities [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_lbl" xml:lang="en-US" id="id_623015_581369_2_1">Major Types of Debt and Equity Securities [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis" xlink:to="us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" xlink:label="us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_lbl" xml:lang="en-US" id="id_623015_581711_1_1">Major Types Of Debt And Equity Securities [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_lbl" xml:lang="en-US" id="id_623015_581711_2_1">Major Types of Debt and Equity Securities [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" xlink:to="us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_MaximumDebtToEbitdaxRatio" xlink:label="oas_MaximumDebtToEbitdaxRatio"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_MaximumDebtToEbitdaxRatio_lbl" xml:lang="en-US" id="id_623015_618769_3_1">The maximum ratio of Total Net Debt to consolidated EBITDAX as required by the entity's debt agreement.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_MaximumDebtToEbitdaxRatio_lbl" xml:lang="en-US" id="id_623015_618769_1_1">Maximum Debt To Ebitdax Ratio</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_MaximumDebtToEbitdaxRatio_lbl" xml:lang="en-US" id="id_623015_618769_2_1">Maximum debt to EBITDAX ratio</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_MaximumDebtToEbitdaxRatio" xlink:to="oas_MaximumDebtToEbitdaxRatio_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_MaximumMember" xlink:label="us-gaap_MaximumMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MaximumMember_lbl" xml:lang="en-US" id="id_623015_577223_1_1">Maximum [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_MaximumMember_lbl" xml:lang="en-US" id="id_623015_577223_2_1">Maximum [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MaximumMember" xlink:to="us-gaap_MaximumMember_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_MinimumCurrentRatio" xlink:label="oas_MinimumCurrentRatio"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_MinimumCurrentRatio_lbl" xml:lang="en-US" id="id_623015_618770_3_1">The minimum current ratio as required by the entity's debt agreement.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_MinimumCurrentRatio_lbl" xml:lang="en-US" id="id_623015_618770_1_1">Minimum Current Ratio</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_MinimumCurrentRatio_lbl" xml:lang="en-US" id="id_623015_618770_2_1">Minimum current ratio</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_MinimumCurrentRatio" xlink:to="oas_MinimumCurrentRatio_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_MinimumMember" xlink:label="us-gaap_MinimumMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MinimumMember_lbl" xml:lang="en-US" id="id_623015_577073_1_1">Minimum [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_MinimumMember_lbl" xml:lang="en-US" id="id_623015_577073_2_1">Minimum [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MinimumMember" xlink:to="us-gaap_MinimumMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_MoneyMarketFundsMember" xlink:label="us-gaap_MoneyMarketFundsMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MoneyMarketFundsMember_lbl" xml:lang="en-US" id="id_623015_576025_1_1">Money Market Funds [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_MoneyMarketFundsMember_lbl" xml:lang="en-US" id="id_623015_576025_2_1">Money Market Funds [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MoneyMarketFundsMember" xlink:to="us-gaap_MoneyMarketFundsMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_NaturalGasReservesMember" xlink:label="us-gaap_NaturalGasReservesMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NaturalGasReservesMember_lbl" xml:lang="en-US" id="id_623015_575937_1_1">Natural Gas Reserves [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NaturalGasReservesMember_lbl" xml:lang="en-US" id="id_623015_575937_2_1">Natural Gas [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NaturalGasReservesMember" xlink:to="us-gaap_NaturalGasReservesMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_NatureOfOperations" xlink:label="us-gaap_NatureOfOperations"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NatureOfOperations_lbl" xml:lang="en-US" id="id_623015_572760_1_1">Nature Of Operations</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NatureOfOperations_lbl" xml:lang="en-US" id="id_623015_572760_2_1">Nature of Business</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NatureOfOperations" xlink:to="us-gaap_NatureOfOperations_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl" xml:lang="en-US" id="id_623015_574995_1_1">Net Cash Provided By Used In Financing Activities</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl" xml:lang="en-US" id="id_623015_574995_6_1">Net cash provided by (used in) financing activities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_lbl" xml:lang="en-US" id="id_623015_574513_1_1">Net Cash Provided By Used In Financing Activities [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_lbl" xml:lang="en-US" id="id_623015_574513_2_1">Cash flows from financing activities:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl" xml:lang="en-US" id="id_623015_567056_1_1">Net Cash Provided By Used In Investing Activities</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl" xml:lang="en-US" id="id_623015_567056_2_1">Net cash used in investing activities</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl" xml:lang="en-US" id="id_623015_567056_6_1">Net cash used in investing activities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl" xml:lang="en-US" id="id_623015_574244_1_1">Net Cash Provided By Used In Investing Activities [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl" xml:lang="en-US" id="id_623015_574244_2_1">Cash flows from investing activities:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl" xml:lang="en-US" id="id_623015_581703_1_1">Net Cash Provided By Used In Operating Activities</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl" xml:lang="en-US" id="id_623015_581703_6_1">Net cash provided by (used in) operating activities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xml:lang="en-US" id="id_623015_582228_1_1">Net Cash Provided By Used In Operating Activities [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xml:lang="en-US" id="id_623015_582228_2_1">Cash flows from operating activities:</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetIncomeLoss_lbl" xml:lang="en-US" id="id_623015_573591_1_1">Net Income Loss</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NetIncomeLoss_lbl" xml:lang="en-US" id="id_623015_573591_2_1">Net income</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetIncomeLoss_lbl" xml:lang="en-US" id="id_623015_573591_6_1">Net income</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetIncomeLoss" xlink:to="us-gaap_NetIncomeLoss_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:label="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_lbl" xml:lang="en-US" id="id_623015_577877_1_1">New Accounting Pronouncements Policy Policy [Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_lbl" xml:lang="en-US" id="id_623015_577877_2_1">Recent Accounting Pronouncements</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:to="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_NonCashAssetRetirementObligations" xlink:label="oas_NonCashAssetRetirementObligations"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_NonCashAssetRetirementObligations_lbl" xml:lang="en-US" id="id_623015_617171_3_1">The net change in asset retirement obligations less any cash paid to settle such obligations during the reporting period.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_NonCashAssetRetirementObligations_lbl" xml:lang="en-US" id="id_623015_617171_1_1">Non Cash Asset Retirement Obligations</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_NonCashAssetRetirementObligations_lbl" xml:lang="en-US" id="id_623015_617171_2_1">Change in asset retirement obligations</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_NonCashAssetRetirementObligations" xlink:to="oas_NonCashAssetRetirementObligations_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_NonoperatingIncomeExpense" xlink:label="us-gaap_NonoperatingIncomeExpense"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NonoperatingIncomeExpense_lbl" xml:lang="en-US" id="id_623015_573615_1_1">Nonoperating Income Expense</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NonoperatingIncomeExpense_lbl" xml:lang="en-US" id="id_623015_573615_6_1">Total other income (expense)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NonoperatingIncomeExpense" xlink:to="us-gaap_NonoperatingIncomeExpense_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_NonoperatingIncomeExpenseAbstract" xlink:label="us-gaap_NonoperatingIncomeExpenseAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NonoperatingIncomeExpenseAbstract_lbl" xml:lang="en-US" id="id_623015_570750_1_1">Nonoperating Income Expense [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NonoperatingIncomeExpenseAbstract_lbl" xml:lang="en-US" id="id_623015_570750_2_1">Other income (expense)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_NonoperatingIncomeExpenseAbstract_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_NumberOfTradingDaysConsiderForAverageClosingPrice" xlink:label="oas_NumberOfTradingDaysConsiderForAverageClosingPrice"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_NumberOfTradingDaysConsiderForAverageClosingPrice_lbl" xml:lang="en-US" id="id_623015_747055_3_1">Number Of Trading Days Consider For Average Closing Price</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_NumberOfTradingDaysConsiderForAverageClosingPrice_lbl" xml:lang="en-US" id="id_623015_747055_1_1">Number Of Trading Days Consider For Average Closing Price</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_NumberOfTradingDaysConsiderForAverageClosingPrice_lbl" xml:lang="en-US" id="id_623015_747055_2_1">Number of trading Days</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_NumberOfTradingDaysConsiderForAverageClosingPrice" xlink:to="oas_NumberOfTradingDaysConsiderForAverageClosingPrice_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_OilAndGasDeliveryCommitmentsAndContractsLineItems" xlink:label="us-gaap_OilAndGasDeliveryCommitmentsAndContractsLineItems"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OilAndGasDeliveryCommitmentsAndContractsLineItems_lbl" xml:lang="en-US" id="id_623015_572709_1_1">Oil And Gas Delivery Commitments And Contracts [Line Items]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OilAndGasDeliveryCommitmentsAndContractsLineItems_lbl" xml:lang="en-US" id="id_623015_572709_2_1">Oil and Gas Delivery Commitments and Contracts [Line Items]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OilAndGasDeliveryCommitmentsAndContractsLineItems" xlink:to="us-gaap_OilAndGasDeliveryCommitmentsAndContractsLineItems_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_OilAndGasDeliveryCommitmentsAndContractsRemainingContractualVolume" xlink:label="us-gaap_OilAndGasDeliveryCommitmentsAndContractsRemainingContractualVolume"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OilAndGasDeliveryCommitmentsAndContractsRemainingContractualVolume_lbl" xml:lang="en-US" id="id_623015_577577_1_1">Oil And Gas Delivery Commitments And Contracts Remaining Contractual Volume</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OilAndGasDeliveryCommitmentsAndContractsRemainingContractualVolume_lbl" xml:lang="en-US" id="id_623015_577577_2_1">Minimum quantity of delivery</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OilAndGasDeliveryCommitmentsAndContractsRemainingContractualVolume" xlink:to="us-gaap_OilAndGasDeliveryCommitmentsAndContractsRemainingContractualVolume_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_OilAndGasDeliveryCommitmentsAndContractsTable" xlink:label="us-gaap_OilAndGasDeliveryCommitmentsAndContractsTable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OilAndGasDeliveryCommitmentsAndContractsTable_lbl" xml:lang="en-US" id="id_623015_573524_1_1">Oil And Gas Delivery Commitments And Contracts [Table]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OilAndGasDeliveryCommitmentsAndContractsTable_lbl" xml:lang="en-US" id="id_623015_573524_2_1">Oil and Gas Delivery Commitments and Contracts [Table]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OilAndGasDeliveryCommitmentsAndContractsTable" xlink:to="us-gaap_OilAndGasDeliveryCommitmentsAndContractsTable_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_OilAndGasJointInterestBillingReceivablesCurrent" xlink:label="us-gaap_OilAndGasJointInterestBillingReceivablesCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OilAndGasJointInterestBillingReceivablesCurrent_lbl" xml:lang="en-US" id="id_623015_566114_1_1">Oil And Gas Joint Interest Billing Receivables Current</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OilAndGasJointInterestBillingReceivablesCurrent_lbl" xml:lang="en-US" id="id_623015_566114_2_1">Accounts receivable - joint interest partners</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OilAndGasJointInterestBillingReceivablesCurrent" xlink:to="us-gaap_OilAndGasJointInterestBillingReceivablesCurrent_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_OilAndGasPropertySuccessfulEffortMethodAccumulatedDepreciationDepletionAndAmortization" xlink:label="us-gaap_OilAndGasPropertySuccessfulEffortMethodAccumulatedDepreciationDepletionAndAmortization"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OilAndGasPropertySuccessfulEffortMethodAccumulatedDepreciationDepletionAndAmortization_lbl" xml:lang="en-US" id="id_623015_565992_1_1">Oil And Gas Property Successful Effort Method Accumulated Depreciation Depletion And Amortization</label>
    <label xlink:type="resource" xlink:role="http://xbrl.us/us-gaap/role/label/negated" xlink:label="us-gaap_OilAndGasPropertySuccessfulEffortMethodAccumulatedDepreciationDepletionAndAmortization_lbl" xml:lang="en-US" id="id_623015_565992_8_1">Less: Accumulated depreciation, depletion, amortization and impairment</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OilAndGasPropertySuccessfulEffortMethodAccumulatedDepreciationDepletionAndAmortization" xlink:to="us-gaap_OilAndGasPropertySuccessfulEffortMethodAccumulatedDepreciationDepletionAndAmortization_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_OilAndGasPropertySuccessfulEffortMethodGross" xlink:label="us-gaap_OilAndGasPropertySuccessfulEffortMethodGross"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OilAndGasPropertySuccessfulEffortMethodGross_lbl" xml:lang="en-US" id="id_623015_581663_1_1">Oil And Gas Property Successful Effort Method Gross</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OilAndGasPropertySuccessfulEffortMethodGross_lbl" xml:lang="en-US" id="id_623015_581663_2_1">Oil and gas properties (successful efforts method)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OilAndGasPropertySuccessfulEffortMethodGross" xlink:to="us-gaap_OilAndGasPropertySuccessfulEffortMethodGross_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_OilAndGasPropertySuccessfulEffortMethodNet" xlink:label="us-gaap_OilAndGasPropertySuccessfulEffortMethodNet"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OilAndGasPropertySuccessfulEffortMethodNet_lbl" xml:lang="en-US" id="id_623015_573831_1_1">Oil And Gas Property Successful Effort Method Net</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_OilAndGasPropertySuccessfulEffortMethodNet_lbl" xml:lang="en-US" id="id_623015_573831_6_1">Oil and gas properties, net</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OilAndGasPropertySuccessfulEffortMethodNet" xlink:to="us-gaap_OilAndGasPropertySuccessfulEffortMethodNet_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_OilAndGasRevenue" xlink:label="us-gaap_OilAndGasRevenue"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OilAndGasRevenue_lbl" xml:lang="en-US" id="id_623015_580017_1_1">Oil And Gas Revenue</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OilAndGasRevenue_lbl" xml:lang="en-US" id="id_623015_580017_2_1">Total revenues</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_OilAndGasRevenue_lbl" xml:lang="en-US" id="id_623015_580017_6_1">Total revenues</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OilAndGasRevenue" xlink:to="us-gaap_OilAndGasRevenue_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_OilAndGasSalesRevenue" xlink:label="us-gaap_OilAndGasSalesRevenue"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OilAndGasSalesRevenue_lbl" xml:lang="en-US" id="id_623015_569898_1_1">Oil And Gas Sales Revenue</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OilAndGasSalesRevenue_lbl" xml:lang="en-US" id="id_623015_569898_2_1">Oil and gas revenues</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OilAndGasSalesRevenue" xlink:to="us-gaap_OilAndGasSalesRevenue_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="us-gaap_OperatingIncomeLoss"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingIncomeLoss_lbl" xml:lang="en-US" id="id_623015_571917_1_1">Operating Income Loss</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OperatingIncomeLoss_lbl" xml:lang="en-US" id="id_623015_571917_2_1">Operating income (loss)</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_OperatingIncomeLoss_lbl" xml:lang="en-US" id="id_623015_571917_6_1">Operating income</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingIncomeLoss" xlink:to="us-gaap_OperatingIncomeLoss_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDue" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDue"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDue_lbl" xml:lang="en-US" id="id_623015_579082_1_1">Operating Leases Future Minimum Payments Due</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDue_lbl" xml:lang="en-US" id="id_623015_579082_2_1">Total rental commitments under leases</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasesFutureMinimumPaymentsDue" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsDue_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock_lbl" xml:lang="en-US" id="id_623015_580349_1_1">Organization Consolidation And Presentation Of Financial Statements Disclosure [Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock_lbl" xml:lang="en-US" id="id_623015_580349_2_1">Organization and Operations of the Company</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock" xlink:to="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_OrganizationPolicyTextBlock" xlink:label="oas_OrganizationPolicyTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_OrganizationPolicyTextBlock_lbl" xml:lang="en-US" id="id_623015_619092_3_1">The entire disclosure for the formation of the organization.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_OrganizationPolicyTextBlock_lbl" xml:lang="en-US" id="id_623015_619092_1_1">Organization Policy [Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_OrganizationPolicyTextBlock_lbl" xml:lang="en-US" id="id_623015_619092_2_1">Organization</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_OrganizationPolicyTextBlock" xlink:to="oas_OrganizationPolicyTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_OtherAssetsCurrent" xlink:label="us-gaap_OtherAssetsCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherAssetsCurrent_lbl" xml:lang="en-US" id="id_623015_566436_1_1">Other Assets Current</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OtherAssetsCurrent_lbl" xml:lang="en-US" id="id_623015_566436_2_1">Other current assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherAssetsCurrent" xlink:to="us-gaap_OtherAssetsCurrent_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_OtherInventorySupplies" xlink:label="us-gaap_OtherInventorySupplies"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherInventorySupplies_lbl" xml:lang="en-US" id="id_623015_579678_1_1">Other Inventory Supplies</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OtherInventorySupplies_lbl" xml:lang="en-US" id="id_623015_579678_2_1">Equipment and materials</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherInventorySupplies" xlink:to="us-gaap_OtherInventorySupplies_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_OtherLiabilitiesCurrent" xlink:label="us-gaap_OtherLiabilitiesCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherLiabilitiesCurrent_lbl" xml:lang="en-US" id="id_623015_573888_1_1">Other Liabilities Current</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OtherLiabilitiesCurrent_lbl" xml:lang="en-US" id="id_623015_573888_2_1">Other current liabilities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherLiabilitiesCurrent" xlink:to="us-gaap_OtherLiabilitiesCurrent_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_OtherLiabilitiesNoncurrent" xlink:label="us-gaap_OtherLiabilitiesNoncurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherLiabilitiesNoncurrent_lbl" xml:lang="en-US" id="id_623015_582001_1_1">Other Liabilities Noncurrent</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OtherLiabilitiesNoncurrent_lbl" xml:lang="en-US" id="id_623015_582001_2_1">Other liabilities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherLiabilitiesNoncurrent" xlink:to="us-gaap_OtherLiabilitiesNoncurrent_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="us-gaap_OtherNonoperatingIncomeExpense"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OtherNonoperatingIncomeExpense_lbl" xml:lang="en-US" id="id_623015_565345_1_1">Other Nonoperating Income Expense</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OtherNonoperatingIncomeExpense_lbl" xml:lang="en-US" id="id_623015_565345_2_1">Other income</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherNonoperatingIncomeExpense" xlink:to="us-gaap_OtherNonoperatingIncomeExpense_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_OwnershipPercentageGuarantor" xlink:label="oas_OwnershipPercentageGuarantor"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_OwnershipPercentageGuarantor_lbl" xml:lang="en-US" id="id_623015_618229_3_1">Ownership percentage, guarantor</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_OwnershipPercentageGuarantor_lbl" xml:lang="en-US" id="id_623015_618229_1_1">Ownership Percentage Guarantor</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_OwnershipPercentageGuarantor_lbl" xml:lang="en-US" id="id_623015_618229_2_1">Ownership percentage, guarantor</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_OwnershipPercentageGuarantor" xlink:to="oas_OwnershipPercentageGuarantor_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ParentCompanyMember" xlink:label="us-gaap_ParentCompanyMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ParentCompanyMember_lbl" xml:lang="en-US" id="id_623015_577509_1_1">Parent Company [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ParentCompanyMember_lbl" xml:lang="en-US" id="id_623015_577509_2_1">Parent/Issuer [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ParentCompanyMember" xlink:to="us-gaap_ParentCompanyMember_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_PaymentsForAdvancesToJointInterestPartners" xlink:label="oas_PaymentsForAdvancesToJointInterestPartners"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_PaymentsForAdvancesToJointInterestPartners_lbl" xml:lang="en-US" id="id_623015_617140_3_1">The net change during the reporting period in the value of the amounts paid in advance to a third party for capital that will be expensed with the passage of time or the occurrence of a triggering event, and will be charged against earnings within one year or the normal operating cycle (if longer).</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_PaymentsForAdvancesToJointInterestPartners_lbl" xml:lang="en-US" id="id_623015_617140_1_1">Payments For Advances To Joint Interest Partners</label>
    <label xlink:type="resource" xlink:role="http://xbrl.us/us-gaap/role/label/negated" xlink:label="oas_PaymentsForAdvancesToJointInterestPartners_lbl" xml:lang="en-US" id="id_623015_617140_8_1">Advances to joint interest partners</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_PaymentsForAdvancesToJointInterestPartners" xlink:to="oas_PaymentsForAdvancesToJointInterestPartners_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_PaymentsForProceedsFromDerivativeInstrumentInvestingActivities" xlink:label="us-gaap_PaymentsForProceedsFromDerivativeInstrumentInvestingActivities"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsForProceedsFromDerivativeInstrumentInvestingActivities_lbl" xml:lang="en-US" id="id_623015_568075_1_1">Payments For Proceeds From Derivative Instrument Investing Activities</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PaymentsForProceedsFromDerivativeInstrumentInvestingActivities_lbl" xml:lang="en-US" id="id_623015_568075_14_1">Realized gain (loss) on derivative instruments</label>
    <label xlink:type="resource" xlink:role="http://xbrl.us/us-gaap/role/label/negated" xlink:label="us-gaap_PaymentsForProceedsFromDerivativeInstrumentInvestingActivities_lbl" xml:lang="en-US" id="id_623015_568075_8_1">Derivative settlements</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsForProceedsFromDerivativeInstrumentInvestingActivities" xlink:to="us-gaap_PaymentsForProceedsFromDerivativeInstrumentInvestingActivities_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_PaymentsOfDebtIssuanceCosts" xlink:label="us-gaap_PaymentsOfDebtIssuanceCosts"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsOfDebtIssuanceCosts_lbl" xml:lang="en-US" id="id_623015_567083_1_1">Payments Of Debt Issuance Costs</label>
    <label xlink:type="resource" xlink:role="http://xbrl.us/us-gaap/role/label/negated" xlink:label="us-gaap_PaymentsOfDebtIssuanceCosts_lbl" xml:lang="en-US" id="id_623015_567083_8_1">Debt issuance costs</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsOfDebtIssuanceCosts" xlink:to="us-gaap_PaymentsOfDebtIssuanceCosts_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation" xlink:label="us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_lbl" xml:lang="en-US" id="id_623015_569411_1_1">Payments Related To Tax Withholding For Share Based Compensation</label>
    <label xlink:type="resource" xlink:role="http://xbrl.us/us-gaap/role/label/negated" xlink:label="us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_lbl" xml:lang="en-US" id="id_623015_569411_8_1">Purchases of treasury stock</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation" xlink:to="us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_PaymentsToAcquireShortTermInvestments" xlink:label="us-gaap_PaymentsToAcquireShortTermInvestments"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsToAcquireShortTermInvestments_lbl" xml:lang="en-US" id="id_623015_580336_1_1">Payments To Acquire Short Term Investments</label>
    <label xlink:type="resource" xlink:role="http://xbrl.us/us-gaap/role/label/negated" xlink:label="us-gaap_PaymentsToAcquireShortTermInvestments_lbl" xml:lang="en-US" id="id_623015_580336_8_1">Purchases of short-term investments</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquireShortTermInvestments" xlink:to="us-gaap_PaymentsToAcquireShortTermInvestments_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_PaymentsToExploreAndDevelopOilAndGasProperties" xlink:label="us-gaap_PaymentsToExploreAndDevelopOilAndGasProperties"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PaymentsToExploreAndDevelopOilAndGasProperties_lbl" xml:lang="en-US" id="id_623015_568301_1_1">Payments To Explore And Develop Oil And Gas Properties</label>
    <label xlink:type="resource" xlink:role="http://xbrl.us/us-gaap/role/label/negated" xlink:label="us-gaap_PaymentsToExploreAndDevelopOilAndGasProperties_lbl" xml:lang="en-US" id="id_623015_568301_8_1">Capital expenditures</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToExploreAndDevelopOilAndGasProperties" xlink:to="us-gaap_PaymentsToExploreAndDevelopOilAndGasProperties_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_PercentageOfMinimumOutstandingPrincipalAmount" xlink:label="oas_PercentageOfMinimumOutstandingPrincipalAmount"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_PercentageOfMinimumOutstandingPrincipalAmount_lbl" xml:lang="en-US" id="id_623015_618285_3_1">Percentage of minimum outstanding principal amount.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_PercentageOfMinimumOutstandingPrincipalAmount_lbl" xml:lang="en-US" id="id_623015_618285_1_1">Percentage Of Minimum Outstanding Principal Amount</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_PercentageOfMinimumOutstandingPrincipalAmount_lbl" xml:lang="en-US" id="id_623015_618285_2_1">Percentage of minimum outstanding principal amount</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_PercentageOfMinimumOutstandingPrincipalAmount" xlink:to="oas_PercentageOfMinimumOutstandingPrincipalAmount_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_PercentageOfPerformanceShareAwardsBasedOnShareholderReturn" xlink:label="oas_PercentageOfPerformanceShareAwardsBasedOnShareholderReturn"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_PercentageOfPerformanceShareAwardsBasedOnShareholderReturn_lbl" xml:lang="en-US" id="id_623015_809661_3_1">Percentage Of Performance Share Awards Based On Shareholder Return</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_PercentageOfPerformanceShareAwardsBasedOnShareholderReturn_lbl" xml:lang="en-US" id="id_623015_809661_1_1">Percentage Of Performance Share Awards Based On Shareholder Return</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_PercentageOfPerformanceShareAwardsBasedOnShareholderReturn_lbl" xml:lang="en-US" id="id_623015_809661_2_1">PSU granted Percentage of earnings</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_PercentageOfPerformanceShareAwardsBasedOnShareholderReturn" xlink:to="oas_PercentageOfPerformanceShareAwardsBasedOnShareholderReturn_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_PercentageOfReserveValueOfAssets" xlink:label="oas_PercentageOfReserveValueOfAssets"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_PercentageOfReserveValueOfAssets_lbl" xml:lang="en-US" id="id_623015_618307_3_1">Percentage of the reserve value as determined by reserve reports that is collateralized under the Amended Credit Facility.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_PercentageOfReserveValueOfAssets_lbl" xml:lang="en-US" id="id_623015_618307_1_1">Percentage Of Reserve Value Of Assets</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_PercentageOfReserveValueOfAssets_lbl" xml:lang="en-US" id="id_623015_618307_2_1">Percentage of the reserve value of assets as determined by reserve reports</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_PercentageOfReserveValueOfAssets" xlink:to="oas_PercentageOfReserveValueOfAssets_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_PerformanceShareUnitAwardsMember" xlink:label="oas_PerformanceShareUnitAwardsMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_PerformanceShareUnitAwardsMember_lbl" xml:lang="en-US" id="id_623015_649178_3_1">Performance Share Unit Awards [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_PerformanceShareUnitAwardsMember_lbl" xml:lang="en-US" id="id_623015_649178_1_1">Performance Share Unit Awards [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_PerformanceShareUnitAwardsMember_lbl" xml:lang="en-US" id="id_623015_649178_2_1">Performance Share Unit Awards [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_PerformanceShareUnitAwardsMember" xlink:to="oas_PerformanceShareUnitAwardsMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_PrepaidExpenseCurrent" xlink:label="us-gaap_PrepaidExpenseCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PrepaidExpenseCurrent_lbl" xml:lang="en-US" id="id_623015_572596_1_1">Prepaid Expense Current</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PrepaidExpenseCurrent_lbl" xml:lang="en-US" id="id_623015_572596_2_1">Prepaid expenses</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PrepaidExpenseCurrent" xlink:to="us-gaap_PrepaidExpenseCurrent_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_ProceedFromAdvanceFromJointInterestPartners" xlink:label="oas_ProceedFromAdvanceFromJointInterestPartners"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_ProceedFromAdvanceFromJointInterestPartners_lbl" xml:lang="en-US" id="id_623015_616895_3_1">The net change during the reporting period in the value of the amounts received in advance for capital projects from our joint interest partners.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_ProceedFromAdvanceFromJointInterestPartners_lbl" xml:lang="en-US" id="id_623015_616895_1_1">Proceed From Advance From Joint Interest Partners</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_ProceedFromAdvanceFromJointInterestPartners_lbl" xml:lang="en-US" id="id_623015_616895_2_1">Advances from joint interest partners</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_ProceedFromAdvanceFromJointInterestPartners" xlink:to="oas_ProceedFromAdvanceFromJointInterestPartners_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ProceedsFromContributionsFromAffiliates" xlink:label="us-gaap_ProceedsFromContributionsFromAffiliates"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromContributionsFromAffiliates_lbl" xml:lang="en-US" id="id_623015_570107_1_1">Proceeds From Contributions From Affiliates</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProceedsFromContributionsFromAffiliates_lbl" xml:lang="en-US" id="id_623015_570107_2_1">Investment in / capital contributions from affiliates</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromContributionsFromAffiliates" xlink:to="us-gaap_ProceedsFromContributionsFromAffiliates_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ProceedsFromIssuanceOfSeniorLongTermDebt" xlink:label="us-gaap_ProceedsFromIssuanceOfSeniorLongTermDebt"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromIssuanceOfSeniorLongTermDebt_lbl" xml:lang="en-US" id="id_623015_569106_1_1">Proceeds From Issuance Of Senior Long Term Debt</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProceedsFromIssuanceOfSeniorLongTermDebt_lbl" xml:lang="en-US" id="id_623015_569106_2_1">Proceeds from issuance of senior notes</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIssuanceOfSeniorLongTermDebt" xlink:to="us-gaap_ProceedsFromIssuanceOfSeniorLongTermDebt_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ProceedsFromIssuanceOfUnsecuredDebt" xlink:label="us-gaap_ProceedsFromIssuanceOfUnsecuredDebt"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromIssuanceOfUnsecuredDebt_lbl" xml:lang="en-US" id="id_623015_575356_1_1">Proceeds From Issuance Of Unsecured Debt</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProceedsFromIssuanceOfUnsecuredDebt_lbl" xml:lang="en-US" id="id_623015_575356_2_1">Net proceeds from issuance of notes</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIssuanceOfUnsecuredDebt" xlink:to="us-gaap_ProceedsFromIssuanceOfUnsecuredDebt_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ProceedsFromSaleMaturityAndCollectionOfShorttermInvestments" xlink:label="us-gaap_ProceedsFromSaleMaturityAndCollectionOfShorttermInvestments"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromSaleMaturityAndCollectionOfShorttermInvestments_lbl" xml:lang="en-US" id="id_623015_577216_1_1">Proceeds From Sale Maturity And Collection Of Shortterm Investments</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProceedsFromSaleMaturityAndCollectionOfShorttermInvestments_lbl" xml:lang="en-US" id="id_623015_577216_2_1">Redemptions of short-term investments</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromSaleMaturityAndCollectionOfShorttermInvestments" xlink:to="us-gaap_ProceedsFromSaleMaturityAndCollectionOfShorttermInvestments_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ProductionTaxExpense" xlink:label="us-gaap_ProductionTaxExpense"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProductionTaxExpense_lbl" xml:lang="en-US" id="id_623015_575137_1_1">Production Tax Expense</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProductionTaxExpense_lbl" xml:lang="en-US" id="id_623015_575137_2_1">Production taxes</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProductionTaxExpense" xlink:to="us-gaap_ProductionTaxExpense_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ProductOrServiceAxis" xlink:label="us-gaap_ProductOrServiceAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProductOrServiceAxis_lbl" xml:lang="en-US" id="id_623015_575370_1_1">Product Or Service [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProductOrServiceAxis_lbl" xml:lang="en-US" id="id_623015_575370_2_1">Products and Services [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProductOrServiceAxis" xlink:to="us-gaap_ProductOrServiceAxis_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ProductsAndServicesDomain" xlink:label="us-gaap_ProductsAndServicesDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProductsAndServicesDomain_lbl" xml:lang="en-US" id="id_623015_578446_1_1">Products And Services [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProductsAndServicesDomain_lbl" xml:lang="en-US" id="id_623015_578446_2_1">Products and Services [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProductsAndServicesDomain" xlink:to="us-gaap_ProductsAndServicesDomain_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis_lbl" xml:lang="en-US" id="id_623015_567990_1_1">Property Plant And Equipment By Type [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis_lbl" xml:lang="en-US" id="id_623015_567990_2_1">Property, Plant and Equipment, Type [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:to="us-gaap_PropertyPlantAndEquipmentByTypeAxis_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" xlink:label="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock_lbl" xml:lang="en-US" id="id_623015_572913_1_1">Property Plant And Equipment Disclosure [Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock_lbl" xml:lang="en-US" id="id_623015_572913_2_1">Property, Plant and Equipment</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" xlink:to="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentLineItems_lbl" xml:lang="en-US" id="id_623015_572317_1_1">Property Plant And Equipment [Line Items]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentLineItems_lbl" xml:lang="en-US" id="id_623015_572317_2_1">Property, Plant and Equipment [Line Items]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="us-gaap_PropertyPlantAndEquipmentLineItems_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="us-gaap_PropertyPlantAndEquipmentNet"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xml:lang="en-US" id="id_623015_577181_1_1">Property Plant And Equipment Net</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xml:lang="en-US" id="id_623015_577181_2_1">Total property, plant and equipment, net</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xml:lang="en-US" id="id_623015_577181_6_1">Total property, plant and equipment, net</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentNet" xlink:to="us-gaap_PropertyPlantAndEquipmentNet_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNetAbstract" xlink:label="us-gaap_PropertyPlantAndEquipmentNetAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentNetAbstract_lbl" xml:lang="en-US" id="id_623015_578606_1_1">Property Plant And Equipment Net [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentNetAbstract_lbl" xml:lang="en-US" id="id_623015_578606_2_1">Property, plant and equipment</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentNetAbstract" xlink:to="us-gaap_PropertyPlantAndEquipmentNetAbstract_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_PropertyPlantAndEquipmentOther" xlink:label="us-gaap_PropertyPlantAndEquipmentOther"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentOther_lbl" xml:lang="en-US" id="id_623015_579467_1_1">Property Plant And Equipment Other</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentOther_lbl" xml:lang="en-US" id="id_623015_579467_2_1">Other property and equipment</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentOther" xlink:to="us-gaap_PropertyPlantAndEquipmentOther_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_PropertyPlantAndEquipmentOtherAccumulatedDepreciation" xlink:label="us-gaap_PropertyPlantAndEquipmentOtherAccumulatedDepreciation"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentOtherAccumulatedDepreciation_lbl" xml:lang="en-US" id="id_623015_576680_1_1">Property Plant And Equipment Other Accumulated Depreciation</label>
    <label xlink:type="resource" xlink:role="http://xbrl.us/us-gaap/role/label/negated" xlink:label="us-gaap_PropertyPlantAndEquipmentOtherAccumulatedDepreciation_lbl" xml:lang="en-US" id="id_623015_576680_8_1">Less: Accumulated depreciation</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentOtherAccumulatedDepreciation" xlink:to="us-gaap_PropertyPlantAndEquipmentOtherAccumulatedDepreciation_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_PropertyPlantAndEquipmentOtherNet" xlink:label="us-gaap_PropertyPlantAndEquipmentOtherNet"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentOtherNet_lbl" xml:lang="en-US" id="id_623015_579979_1_1">Property Plant And Equipment Other Net</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentOtherNet_lbl" xml:lang="en-US" id="id_623015_579979_6_1">Other property and equipment, net</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentOtherNet" xlink:to="us-gaap_PropertyPlantAndEquipmentOtherNet_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTextBlock" xlink:label="us-gaap_PropertyPlantAndEquipmentTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentTextBlock_lbl" xml:lang="en-US" id="id_623015_572469_1_1">Property Plant And Equipment [Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentTextBlock_lbl" xml:lang="en-US" id="id_623015_572469_2_1">Schedule of Property, Plant and Equipment</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentTextBlock" xlink:to="us-gaap_PropertyPlantAndEquipmentTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentTypeDomain_lbl" xml:lang="en-US" id="id_623015_565566_1_1">Property Plant And Equipment Type [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentTypeDomain_lbl" xml:lang="en-US" id="id_623015_565566_2_1">Property, Plant and Equipment, Type [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_PropertyPlantAndEquipmentTypeDomain_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_ProvedOilAndGasPropertiesNet" xlink:label="oas_ProvedOilAndGasPropertiesNet"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_ProvedOilAndGasPropertiesNet_lbl" xml:lang="en-US" id="id_623015_616952_3_1">Oil and Gas properties with proved reserves under the successful effort method, net of accumulated depreciation, depletion, amortization and impairment.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_ProvedOilAndGasPropertiesNet_lbl" xml:lang="en-US" id="id_623015_616952_1_1">Proved Oil And Gas Properties Net</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="oas_ProvedOilAndGasPropertiesNet_lbl" xml:lang="en-US" id="id_623015_616952_6_1">Proved oil and gas properties, net</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_ProvedOilAndGasPropertiesNet" xlink:to="oas_ProvedOilAndGasPropertiesNet_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ProvedOilAndGasPropertySuccessfulEffortMethod" xlink:label="us-gaap_ProvedOilAndGasPropertySuccessfulEffortMethod"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProvedOilAndGasPropertySuccessfulEffortMethod_lbl" xml:lang="en-US" id="id_623015_569067_1_1">Proved Oil And Gas Property Successful Effort Method</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProvedOilAndGasPropertySuccessfulEffortMethod_lbl" xml:lang="en-US" id="id_623015_569067_2_1">Proved oil and gas properties</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProvedOilAndGasPropertySuccessfulEffortMethod" xlink:to="us-gaap_ProvedOilAndGasPropertySuccessfulEffortMethod_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_RangeAxis" xlink:label="us-gaap_RangeAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RangeAxis_lbl" xml:lang="en-US" id="id_623015_568913_1_1">Range [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RangeAxis_lbl" xml:lang="en-US" id="id_623015_568913_2_1">Range [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RangeAxis" xlink:to="us-gaap_RangeAxis_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_RangeMember" xlink:label="us-gaap_RangeMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RangeMember_lbl" xml:lang="en-US" id="id_623015_566530_1_1">Range [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RangeMember_lbl" xml:lang="en-US" id="id_623015_566530_2_1">Range [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RangeMember" xlink:to="us-gaap_RangeMember_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_RatioOfEbitdaxToInterestExpenseNecessaryToMaintainCovenants" xlink:label="oas_RatioOfEbitdaxToInterestExpenseNecessaryToMaintainCovenants"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_RatioOfEbitdaxToInterestExpenseNecessaryToMaintainCovenants_lbl" xml:lang="en-US" id="id_623015_629979_3_1">The maximum ratio of consolidated EBITDAX to consolidated Interest Expense as required by the entity's debt agreement.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_RatioOfEbitdaxToInterestExpenseNecessaryToMaintainCovenants_lbl" xml:lang="en-US" id="id_623015_629979_1_1">Ratio Of Ebitdax To Interest Expense Necessary To Maintain Covenants</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_RatioOfEbitdaxToInterestExpenseNecessaryToMaintainCovenants_lbl" xml:lang="en-US" id="id_623015_629979_2_1">Maximum EBITDAX to Interest Expense ratio</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_RatioOfEbitdaxToInterestExpenseNecessaryToMaintainCovenants" xlink:to="oas_RatioOfEbitdaxToInterestExpenseNecessaryToMaintainCovenants_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_RatioOfTotalOutstandingBorrowingsToBorrowingBase" xlink:label="oas_RatioOfTotalOutstandingBorrowingsToBorrowingBase"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_RatioOfTotalOutstandingBorrowingsToBorrowingBase_lbl" xml:lang="en-US" id="id_623015_618773_3_1">Ratio of total outstanding borrowings to borrowing base.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_RatioOfTotalOutstandingBorrowingsToBorrowingBase_lbl" xml:lang="en-US" id="id_623015_618773_1_1">Ratio Of Total Outstanding Borrowings To Borrowing Base</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_RatioOfTotalOutstandingBorrowingsToBorrowingBase_lbl" xml:lang="en-US" id="id_623015_618773_2_1">Ratio of Total Outstanding Borrowings to Borrowing Base</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_RatioOfTotalOutstandingBorrowingsToBorrowingBase" xlink:to="oas_RatioOfTotalOutstandingBorrowingsToBorrowingBase_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_RatioOfTotalOutstandingBorrowingsToBorrowingBaseDomain" xlink:label="oas_RatioOfTotalOutstandingBorrowingsToBorrowingBaseDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_RatioOfTotalOutstandingBorrowingsToBorrowingBaseDomain_lbl" xml:lang="en-US" id="id_623015_615941_3_1">Ratio Of Total Outstanding Borrowings To Borrowing Base [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_RatioOfTotalOutstandingBorrowingsToBorrowingBaseDomain_lbl" xml:lang="en-US" id="id_623015_615941_1_1">Ratio Of Total Outstanding Borrowings To Borrowing Base [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_RatioOfTotalOutstandingBorrowingsToBorrowingBaseDomain_lbl" xml:lang="en-US" id="id_623015_615941_2_1">Ratio Of Total Outstanding Borrowings To Borrowing Base [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_RatioOfTotalOutstandingBorrowingsToBorrowingBaseDomain" xlink:to="oas_RatioOfTotalOutstandingBorrowingsToBorrowingBaseDomain_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_RatioOfTotalOutstandingBorrowingToBorrowingBaseAxis" xlink:label="oas_RatioOfTotalOutstandingBorrowingToBorrowingBaseAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_RatioOfTotalOutstandingBorrowingToBorrowingBaseAxis_lbl" xml:lang="en-US" id="id_623015_614560_3_1">Ratio Of Total Outstanding Borrowing To Borrowing Base [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_RatioOfTotalOutstandingBorrowingToBorrowingBaseAxis_lbl" xml:lang="en-US" id="id_623015_614560_1_1">Ratio Of Total Outstanding Borrowing To Borrowing Base [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_RatioOfTotalOutstandingBorrowingToBorrowingBaseAxis_lbl" xml:lang="en-US" id="id_623015_614560_2_1">Ratio Of Total Outstanding Borrowing To Borrowing Base [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_RatioOfTotalOutstandingBorrowingToBorrowingBaseAxis" xlink:to="oas_RatioOfTotalOutstandingBorrowingToBorrowingBaseAxis_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_ReconciliationOfBasicWeightedAverageSharesToDilutedWeightedAverageSharesTable" xlink:label="oas_ReconciliationOfBasicWeightedAverageSharesToDilutedWeightedAverageSharesTable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_ReconciliationOfBasicWeightedAverageSharesToDilutedWeightedAverageSharesTable_lbl" xml:lang="en-US" id="id_623015_639479_3_1">Reconciliation Of Basic Weighted Average Shares To Diluted Weighted Average Shares [Table]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_ReconciliationOfBasicWeightedAverageSharesToDilutedWeightedAverageSharesTable_lbl" xml:lang="en-US" id="id_623015_639479_1_1">Reconciliation Of Basic Weighted Average Shares To Diluted Weighted Average Shares [Table]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_ReconciliationOfBasicWeightedAverageSharesToDilutedWeightedAverageSharesTable_lbl" xml:lang="en-US" id="id_623015_639479_2_1">Reconciliation Of Basic Weighted Average Shares To Diluted Weighted Average Shares [Table]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_ReconciliationOfBasicWeightedAverageSharesToDilutedWeightedAverageSharesTable" xlink:to="oas_ReconciliationOfBasicWeightedAverageSharesToDilutedWeightedAverageSharesTable_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_RedemptionPercentageMaximum" xlink:label="oas_RedemptionPercentageMaximum"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_RedemptionPercentageMaximum_lbl" xml:lang="en-US" id="id_623015_618339_3_1">Redemption Percentage, Maximum.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_RedemptionPercentageMaximum_lbl" xml:lang="en-US" id="id_623015_618339_1_1">Redemption Percentage Maximum</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_RedemptionPercentageMaximum_lbl" xml:lang="en-US" id="id_623015_618339_2_1">Redemption percentage, maximum</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_RedemptionPercentageMaximum" xlink:to="oas_RedemptionPercentageMaximum_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_RestrictedStockValueSharesIssuedNetOfTaxWithholdings" xlink:label="us-gaap_RestrictedStockValueSharesIssuedNetOfTaxWithholdings"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_RestrictedStockValueSharesIssuedNetOfTaxWithholdings_lbl" xml:lang="en-US" id="id_623015_566182_1_1">Restricted Stock Value Shares Issued Net Of Tax Withholdings</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RestrictedStockValueSharesIssuedNetOfTaxWithholdings_lbl" xml:lang="en-US" id="id_623015_566182_2_1">Vesting of restricted shares</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestrictedStockValueSharesIssuedNetOfTaxWithholdings" xlink:to="us-gaap_RestrictedStockValueSharesIssuedNetOfTaxWithholdings_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" xml:lang="en-US" id="id_623015_569172_2_1">Retained earnings</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_ScheduleOfCondensedConsolidatingStatementOfOperationsTableTextBlock_lbl" xml:lang="en-US" id="id_623015_607424_3_1">Schedule Of Condensed Consolidating Statement Of Operations [Table Text Block]</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ScheduleOfWeightedAverageNumberOfSharesTableTextBlock" xlink:label="us-gaap_ScheduleOfWeightedAverageNumberOfSharesTableTextBlock"/>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfWeightedAverageNumberOfSharesTableTextBlock" xlink:to="us-gaap_ScheduleOfWeightedAverageNumberOfSharesTableTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ShareBasedCompensation" xlink:label="us-gaap_ShareBasedCompensation"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensation_lbl" xml:lang="en-US" id="id_623015_570386_1_1">Share Based Compensation</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensation_lbl" xml:lang="en-US" id="id_623015_570386_2_1">Stock-based compensation expense</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_ShareBasedCompensation_lbl" xml:lang="en-US" id="id_623015_570386_12_1">Stock-based compensation expenses</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensation" xlink:to="us-gaap_ShareBasedCompensation_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_lbl" xml:lang="en-US" id="id_623015_577388_1_1">Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeited In Period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_lbl" xml:lang="en-US" id="id_623015_577388_2_1">Forfeited</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_lbl" xml:lang="en-US" id="id_623015_577710_1_1">Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_lbl" xml:lang="en-US" id="id_623015_577710_2_1">Granted</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US" id="id_623015_567370_1_1">Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Weighted Average Grant Date Fair Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US" id="id_623015_567370_2_1">Fair value of PSU</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsPerformancePeriod" xlink:label="oas_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsPerformancePeriod"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsPerformancePeriod_lbl" xml:lang="en-US" id="id_623015_609071_3_1">The initial performance period for the performance share units.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsPerformancePeriod_lbl" xml:lang="en-US" id="id_623015_609071_1_1">Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants Performance Period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsPerformancePeriod_lbl" xml:lang="en-US" id="id_623015_609071_2_1">Performance share units initial performance period, years</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsPerformancePeriod" xlink:to="oas_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsPerformancePeriod_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_lbl" xml:lang="en-US" id="id_623015_573112_1_1">Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Number</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_lbl" xml:lang="en-US" id="id_623015_573112_4_1">Non-vested PSUs at September 30, 2012</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_lbl" xml:lang="en-US" id="id_623015_573112_5_1">Non-vested PSUs at December 31, 2011</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueAmortizationPeriod" xlink:label="oas_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueAmortizationPeriod"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueAmortizationPeriod_lbl" xml:lang="en-US" id="id_623015_754360_3_1">The period over which the grant date fair value will amortized.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueAmortizationPeriod_lbl" xml:lang="en-US" id="id_623015_754360_1_1">Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Weighted Average Grant Date Fair Value Amortization Period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueAmortizationPeriod_lbl" xml:lang="en-US" id="id_623015_754360_2_1">Amortized performance period</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueAmortizationPeriod" xlink:to="oas_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueAmortizationPeriod_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_lbl" xml:lang="en-US" id="id_623015_576196_1_1">Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_lbl" xml:lang="en-US" id="id_623015_576196_2_1">Vested</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_lbl" xml:lang="en-US" id="id_623015_568817_1_1">Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term 1</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_lbl" xml:lang="en-US" id="id_623015_568817_2_1">Forecast period (years)</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_lbl" xml:lang="en-US" id="id_623015_575282_1_1">Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_lbl" xml:lang="en-US" id="id_623015_575282_2_1">Oasis volatility</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_lbl" xml:lang="en-US" id="id_623015_573840_1_1">Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_lbl" xml:lang="en-US" id="id_623015_573840_2_1">Risk-free rate</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_lbl" xml:lang="en-US" id="id_623015_569025_1_1">Share Based Compensation Arrangement By Share Based Payment Award [Line Items]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_lbl" xml:lang="en-US" id="id_623015_569025_2_1">Share-based Compensation Arrangement by Share-based Payment Award [Line Items]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" xlink:label="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy_lbl" xml:lang="en-US" id="id_623015_578626_1_1">Share Based Compensation Option And Incentive Plans Policy</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy_lbl" xml:lang="en-US" id="id_623015_578626_2_1">Stock Based Compensation Performance Share Units</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" xlink:to="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_ShareBasedCompensationOtherThanOptionAxis" xlink:label="oas_ShareBasedCompensationOtherThanOptionAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_ShareBasedCompensationOtherThanOptionAxis_lbl" xml:lang="en-US" id="id_623015_726492_3_1">Share Based Compensation Other Than Option [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_ShareBasedCompensationOtherThanOptionAxis_lbl" xml:lang="en-US" id="id_623015_726492_1_1">Share Based Compensation Other Than Option [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_ShareBasedCompensationOtherThanOptionAxis_lbl" xml:lang="en-US" id="id_623015_726492_2_1">Share Based Compensation Other Than Option [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_ShareBasedCompensationOtherThanOptionAxis" xlink:to="oas_ShareBasedCompensationOtherThanOptionAxis_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_ShareBasedCompensationOtherThanOptionDomain" xlink:label="oas_ShareBasedCompensationOtherThanOptionDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_ShareBasedCompensationOtherThanOptionDomain_lbl" xml:lang="en-US" id="id_623015_726758_3_1">Share Based Compensation Other Than Option [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_ShareBasedCompensationOtherThanOptionDomain_lbl" xml:lang="en-US" id="id_623015_726758_1_1">Share Based Compensation Other Than Option [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_ShareBasedCompensationOtherThanOptionDomain_lbl" xml:lang="en-US" id="id_623015_726758_2_1">Share Based Compensation Other Than Option [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_ShareBasedCompensationOtherThanOptionDomain" xlink:to="oas_ShareBasedCompensationOtherThanOptionDomain_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_SharesIssued" xlink:label="us-gaap_SharesIssued"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharesIssued_lbl" xml:lang="en-US" id="id_623015_565363_1_1">Shares Issued</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_SharesIssued_lbl" xml:lang="en-US" id="id_623015_565363_5_1">Balance, shares</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation" xlink:label="us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation_lbl" xml:lang="en-US" id="id_623015_569716_1_1">Shares Paid For Tax Withholding For Share Based Compensation</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation_lbl" xml:lang="en-US" id="id_623015_569716_2_1">Treasury stock - tax withholdings, shares</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation" xlink:to="us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_ShortTermInvestments" xlink:label="us-gaap_ShortTermInvestments"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShortTermInvestments_lbl" xml:lang="en-US" id="id_623015_570072_1_1">Short Term Investments</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShortTermInvestments_lbl" xml:lang="en-US" id="id_623015_570072_2_1">Short-term investments</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShortTermInvestments" xlink:to="us-gaap_ShortTermInvestments_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_SignificantAccountingPoliciesTextBlock" xlink:label="us-gaap_SignificantAccountingPoliciesTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SignificantAccountingPoliciesTextBlock_lbl" xml:lang="en-US" id="id_623015_579068_1_1">Significant Accounting Policies [Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SignificantAccountingPoliciesTextBlock_lbl" xml:lang="en-US" id="id_623015_579068_2_1">Summary of Significant Accounting Policies</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SignificantAccountingPoliciesTextBlock" xlink:to="us-gaap_SignificantAccountingPoliciesTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="us-gaap_StatementEquityComponentsAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementEquityComponentsAxis_lbl" xml:lang="en-US" id="id_623015_570904_1_1">Statement Equity Components [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StatementEquityComponentsAxis_lbl" xml:lang="en-US" id="id_623015_570904_2_1">Equity Components [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_StatementEquityComponentsAxis_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_StatementLineItems" xlink:label="us-gaap_StatementLineItems"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementLineItems_lbl" xml:lang="en-US" id="id_623015_569151_1_1">Statement [Line Items]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StatementLineItems_lbl" xml:lang="en-US" id="id_623015_569151_2_1">Statement [Line Items]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StatementLineItems_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_StatementOfCashFlowsAbstract" xlink:label="us-gaap_StatementOfCashFlowsAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementOfCashFlowsAbstract_lbl" xml:lang="en-US" id="id_623015_576739_1_1">Statement Of Cash Flows [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StatementOfCashFlowsAbstract_lbl" xml:lang="en-US" id="id_623015_576739_2_1">Statement of Cash Flows [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_StatementOfCashFlowsAbstract_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_StatementOfFinancialPositionAbstract" xlink:label="us-gaap_StatementOfFinancialPositionAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementOfFinancialPositionAbstract_lbl" xml:lang="en-US" id="id_623015_574683_1_1">Statement Of Financial Position [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StatementOfFinancialPositionAbstract_lbl" xml:lang="en-US" id="id_623015_574683_2_1">Statement of Financial Position [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_StatementOfFinancialPositionAbstract_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_StatementOfStockholdersEquityAbstract" xlink:label="us-gaap_StatementOfStockholdersEquityAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementOfStockholdersEquityAbstract_lbl" xml:lang="en-US" id="id_623015_568655_1_1">Statement Of Stockholders Equity [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StatementOfStockholdersEquityAbstract_lbl" xml:lang="en-US" id="id_623015_568655_2_1">Statement of Stockholders' Equity [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOfStockholdersEquityAbstract" xlink:to="us-gaap_StatementOfStockholdersEquityAbstract_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_StatementTable" xlink:label="us-gaap_StatementTable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StatementTable_lbl" xml:lang="en-US" id="id_623015_569494_1_1">Statement [Table]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StatementTable_lbl" xml:lang="en-US" id="id_623015_569494_2_1">Statement [Table]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementTable_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="us-gaap_StockholdersEquity"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockholdersEquity_lbl" xml:lang="en-US" id="id_623015_581392_1_1">Stockholders Equity</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_StockholdersEquity_lbl" xml:lang="en-US" id="id_623015_581392_4_1">Balance</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_StockholdersEquity_lbl" xml:lang="en-US" id="id_623015_581392_5_1">Balance</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_StockholdersEquity_lbl" xml:lang="en-US" id="id_623015_581392_6_1">Total stockholders' equity</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_StockholdersEquity_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_StockholdersEquityAbstract" xlink:label="us-gaap_StockholdersEquityAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockholdersEquityAbstract_lbl" xml:lang="en-US" id="id_623015_572017_1_1">Stockholders Equity [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StockholdersEquityAbstract_lbl" xml:lang="en-US" id="id_623015_572017_2_1">Stockholders' equity</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityAbstract" xlink:to="us-gaap_StockholdersEquityAbstract_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" xlink:label="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_lbl" xml:lang="en-US" id="id_623015_578926_1_1">Stock Issued During Period Shares Share Based Compensation</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_lbl" xml:lang="en-US" id="id_623015_578926_2_1">Stock-based compensation, shares</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" xlink:to="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_SubsequentEventLineItems" xlink:label="us-gaap_SubsequentEventLineItems"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsequentEventLineItems_lbl" xml:lang="en-US" id="id_623015_578894_1_1">Subsequent Event [Line Items]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SubsequentEventLineItems_lbl" xml:lang="en-US" id="id_623015_578894_2_1">Subsequent Event [Line Items]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventLineItems" xlink:to="us-gaap_SubsequentEventLineItems_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_SubsequentEventMember" xlink:label="us-gaap_SubsequentEventMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsequentEventMember_lbl" xml:lang="en-US" id="id_623015_579914_1_1">Subsequent Event [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SubsequentEventMember_lbl" xml:lang="en-US" id="id_623015_579914_2_1">Subsequent Event [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventMember" xlink:to="us-gaap_SubsequentEventMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_SubsequentEventsTextBlock" xlink:label="us-gaap_SubsequentEventsTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsequentEventsTextBlock_lbl" xml:lang="en-US" id="id_623015_567355_1_1">Subsequent Events [Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SubsequentEventsTextBlock_lbl" xml:lang="en-US" id="id_623015_567355_2_1">Subsequent Events</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventsTextBlock" xlink:to="us-gaap_SubsequentEventsTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_SubsequentEventTable" xlink:label="us-gaap_SubsequentEventTable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsequentEventTable_lbl" xml:lang="en-US" id="id_623015_566201_1_1">Subsequent Event [Table]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SubsequentEventTable_lbl" xml:lang="en-US" id="id_623015_566201_2_1">Subsequent Event [Table]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventTable" xlink:to="us-gaap_SubsequentEventTable_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="us-gaap_SubsequentEventTypeAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsequentEventTypeAxis_lbl" xml:lang="en-US" id="id_623015_576298_1_1">Subsequent Event Type [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SubsequentEventTypeAxis_lbl" xml:lang="en-US" id="id_623015_576298_2_1">Subsequent Event Type [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventTypeAxis" xlink:to="us-gaap_SubsequentEventTypeAxis_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="us-gaap_SubsequentEventTypeDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SubsequentEventTypeDomain_lbl" xml:lang="en-US" id="id_623015_567999_1_1">Subsequent Event Type [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SubsequentEventTypeDomain_lbl" xml:lang="en-US" id="id_623015_567999_2_1">Subsequent Event Type [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsequentEventTypeDomain" xlink:to="us-gaap_SubsequentEventTypeDomain_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_SupplyCommitmentArrangementMember" xlink:label="us-gaap_SupplyCommitmentArrangementMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SupplyCommitmentArrangementMember_lbl" xml:lang="en-US" id="id_623015_570222_1_1">Supply Commitment Arrangement [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SupplyCommitmentArrangementMember_lbl" xml:lang="en-US" id="id_623015_570222_2_1">Supply Commitment Arrangement [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SupplyCommitmentArrangementMember" xlink:to="us-gaap_SupplyCommitmentArrangementMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_SupplyCommitmentAxis" xlink:label="us-gaap_SupplyCommitmentAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SupplyCommitmentAxis_lbl" xml:lang="en-US" id="id_623015_578432_1_1">Supply Commitment [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SupplyCommitmentAxis_lbl" xml:lang="en-US" id="id_623015_578432_2_1">Supply Commitment [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SupplyCommitmentAxis" xlink:to="us-gaap_SupplyCommitmentAxis_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_TextBlockAbstract" xlink:label="us-gaap_TextBlockAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_TextBlockAbstract_lbl" xml:lang="en-US" id="id_623015_579246_1_1">Text Block [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_TextBlockAbstract_lbl" xml:lang="en-US" id="id_623015_579246_2_1">Text Block [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TextBlockAbstract" xlink:to="us-gaap_TextBlockAbstract_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2012/dei-2012-01-31.xsd#dei_TradingSymbol" xlink:label="dei_TradingSymbol"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_TradingSymbol_lbl" xml:lang="en-US" id="id_623015_565193_1_1">Trading Symbol</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="dei_TradingSymbol_lbl" xml:lang="en-US" id="id_623015_565193_2_1">Trading Symbol</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_TradingSymbol" xlink:to="dei_TradingSymbol_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_TreasuryStockAtCost" xlink:label="oas_TreasuryStockAtCost"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_TreasuryStockAtCost_lbl" xml:lang="en-US" id="id_623015_618881_3_1">For net-share settlement of share-based awards when the employer settles employees' income tax withholding obligations, this element represents the number of shares the employees use to repay the employer.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_TreasuryStockAtCost_lbl" xml:lang="en-US" id="id_623015_618881_1_1">Treasury Stock At Cost</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_TreasuryStockAtCost_lbl" xml:lang="en-US" id="id_623015_618881_2_1">Treasury stock Shares</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="oas_TreasuryStockAtCost_lbl" xml:lang="en-US" id="id_623015_618881_12_1">Treasury stock, shares</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_TreasuryStockAtCost" xlink:to="oas_TreasuryStockAtCost_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_TreasuryStockCost" xlink:label="oas_TreasuryStockCost"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_TreasuryStockCost_lbl" xml:lang="en-US" id="id_623015_616814_3_1">The value of treasury shares withheld by the Company equivalent to the payroll tax obligations due from employees upon the vesting of restricted stock awards.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_TreasuryStockCost_lbl" xml:lang="en-US" id="id_623015_616814_1_1">Treasury Stock Cost</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="oas_TreasuryStockCost_lbl" xml:lang="en-US" id="id_623015_616814_14_1">Treasury stock, at cost; 66,125 and 22,479 shares at September 30, 2012 and December 31, 2011, respectively</label>
    <label xlink:type="resource" xlink:role="http://xbrl.us/us-gaap/role/label/negated" xlink:label="oas_TreasuryStockCost_lbl" xml:lang="en-US" id="id_623015_616814_8_1">Treasury stock, at cost; 22,479 shares</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_TreasuryStockCost" xlink:to="oas_TreasuryStockCost_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_TreasuryStockWithheldMember" xlink:label="oas_TreasuryStockWithheldMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_TreasuryStockWithheldMember_lbl" xml:lang="en-US" id="id_623015_616358_3_1">Shares of an entity that have been withheld by the entity equivalent to the payroll tax withholding obligations due from employees upon the vesting of restricted stock awards during the period.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_TreasuryStockWithheldMember_lbl" xml:lang="en-US" id="id_623015_616358_1_1">Treasury Stock Withheld [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_TreasuryStockWithheldMember_lbl" xml:lang="en-US" id="id_623015_616358_2_1">Treasury Stock [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_TreasuryStockWithheldMember" xlink:to="oas_TreasuryStockWithheldMember_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_TwoThousandFifteenThreeWayCollarsMember" xlink:label="oas_TwoThousandFifteenThreeWayCollarsMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_TwoThousandFifteenThreeWayCollarsMember_lbl" xml:lang="en-US" id="id_623015_697281_3_1">Two Thousand Fifteen Three Way Collars [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_TwoThousandFifteenThreeWayCollarsMember_lbl" xml:lang="en-US" id="id_623015_697281_1_1">Two Thousand Fifteen Three Way Collars [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_TwoThousandFifteenThreeWayCollarsMember_lbl" xml:lang="en-US" id="id_623015_697281_2_1">2015 Three Way Collars [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_TwoThousandFifteenThreeWayCollarsMember" xlink:to="oas_TwoThousandFifteenThreeWayCollarsMember_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_TwoThousandFourteenPutSpreadsMember" xlink:label="oas_TwoThousandFourteenPutSpreadsMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_TwoThousandFourteenPutSpreadsMember_lbl" xml:lang="en-US" id="id_623015_697280_3_1">Two Thousand Fourteen Put Spreads [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_TwoThousandFourteenPutSpreadsMember_lbl" xml:lang="en-US" id="id_623015_697280_1_1">Two Thousand Fourteen Put Spreads [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_TwoThousandFourteenPutSpreadsMember_lbl" xml:lang="en-US" id="id_623015_697280_2_1">2014 Put Spreads [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_TwoThousandFourteenPutSpreadsMember" xlink:to="oas_TwoThousandFourteenPutSpreadsMember_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_TwoThousandFourteenSwapContractsMember" xlink:label="oas_TwoThousandFourteenSwapContractsMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_TwoThousandFourteenSwapContractsMember_lbl" xml:lang="en-US" id="id_623015_639163_3_1">Two Thousand Fourteen Swap Contracts [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_TwoThousandFourteenSwapContractsMember_lbl" xml:lang="en-US" id="id_623015_639163_1_1">Two Thousand Fourteen Swap Contracts [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_TwoThousandFourteenSwapContractsMember_lbl" xml:lang="en-US" id="id_623015_639163_2_1">Two Thousand Fourteen Swap Contracts [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_TwoThousandFourteenSwapContractsMember" xlink:to="oas_TwoThousandFourteenSwapContractsMember_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_TwoThousandFourteenThreeWayCollarsMember" xlink:label="oas_TwoThousandFourteenThreeWayCollarsMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_TwoThousandFourteenThreeWayCollarsMember_lbl" xml:lang="en-US" id="id_623015_616312_3_1">Two Thousand Fourteen, Three-Way Collars [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_TwoThousandFourteenThreeWayCollarsMember_lbl" xml:lang="en-US" id="id_623015_616312_1_1">Two Thousand Fourteen Three Way Collars [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_TwoThousandFourteenThreeWayCollarsMember_lbl" xml:lang="en-US" id="id_623015_616312_2_1">2014 Three-Way Collars [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_TwoThousandFourteenThreeWayCollarsMember" xlink:to="oas_TwoThousandFourteenThreeWayCollarsMember_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_TwoThousandFourteenTwoWayAndThreeWayCollarsMember" xlink:label="oas_TwoThousandFourteenTwoWayAndThreeWayCollarsMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_TwoThousandFourteenTwoWayAndThreeWayCollarsMember_lbl" xml:lang="en-US" id="id_623015_616313_3_1">Two Thousand Fourteen, Two-Way And Three-Way Collars [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_TwoThousandFourteenTwoWayAndThreeWayCollarsMember_lbl" xml:lang="en-US" id="id_623015_616313_1_1">Two Thousand Fourteen Two Way And Three Way Collars [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_TwoThousandFourteenTwoWayAndThreeWayCollarsMember_lbl" xml:lang="en-US" id="id_623015_616313_2_1">2014 Two-Way And Three-Way Collars [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_TwoThousandFourteenTwoWayAndThreeWayCollarsMember" xlink:to="oas_TwoThousandFourteenTwoWayAndThreeWayCollarsMember_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_TwoThousandFourteenTwoWayCollarsMember" xlink:label="oas_TwoThousandFourteenTwoWayCollarsMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_TwoThousandFourteenTwoWayCollarsMember_lbl" xml:lang="en-US" id="id_623015_616314_3_1">Two Thousand Fourteen, Two-Way Collars [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_TwoThousandFourteenTwoWayCollarsMember_lbl" xml:lang="en-US" id="id_623015_616314_1_1">Two Thousand Fourteen Two Way Collars [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_TwoThousandFourteenTwoWayCollarsMember_lbl" xml:lang="en-US" id="id_623015_616314_2_1">2014 Two-Way Collars [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_TwoThousandFourteenTwoWayCollarsMember" xlink:to="oas_TwoThousandFourteenTwoWayCollarsMember_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_TwoThousandNineteenNotesMember" xlink:label="oas_TwoThousandNineteenNotesMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_TwoThousandNineteenNotesMember_lbl" xml:lang="en-US" id="id_623015_616317_3_1">Two Thousand Nineteen Notes [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_TwoThousandNineteenNotesMember_lbl" xml:lang="en-US" id="id_623015_616317_1_1">Two Thousand Nineteen Notes [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_TwoThousandNineteenNotesMember_lbl" xml:lang="en-US" id="id_623015_616317_2_1">2019 Notes [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_TwoThousandNineteenNotesMember" xlink:to="oas_TwoThousandNineteenNotesMember_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_TwoThousandThirteenPutSpreadsMember" xlink:label="oas_TwoThousandThirteenPutSpreadsMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_TwoThousandThirteenPutSpreadsMember_lbl" xml:lang="en-US" id="id_623015_697279_3_1">Two Thousand Thirteen Put Spreads [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_TwoThousandThirteenPutSpreadsMember_lbl" xml:lang="en-US" id="id_623015_697279_1_1">Two Thousand Thirteen Put Spreads [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_TwoThousandThirteenPutSpreadsMember_lbl" xml:lang="en-US" id="id_623015_697279_2_1">2013 Put Spreads [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_TwoThousandThirteenPutSpreadsMember" xlink:to="oas_TwoThousandThirteenPutSpreadsMember_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_TwoThousandThirteenSwapContractsMember" xlink:label="oas_TwoThousandThirteenSwapContractsMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_TwoThousandThirteenSwapContractsMember_lbl" xml:lang="en-US" id="id_623015_639170_3_1">Two Thousand Thirteen Swap Contracts [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_TwoThousandThirteenSwapContractsMember_lbl" xml:lang="en-US" id="id_623015_639170_1_1">Two Thousand Thirteen Swap Contracts [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_TwoThousandThirteenSwapContractsMember_lbl" xml:lang="en-US" id="id_623015_639170_2_1">Two Thousand Thirteen Swap Contracts [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_TwoThousandThirteenSwapContractsMember" xlink:to="oas_TwoThousandThirteenSwapContractsMember_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_TwoThousandThirteenThreeWayCollarsMember" xlink:label="oas_TwoThousandThirteenThreeWayCollarsMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_TwoThousandThirteenThreeWayCollarsMember_lbl" xml:lang="en-US" id="id_623015_616328_3_1">Two Thousand Thirteen, Three-Way Collars [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_TwoThousandThirteenThreeWayCollarsMember_lbl" xml:lang="en-US" id="id_623015_616328_1_1">Two Thousand Thirteen Three Way Collars [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_TwoThousandThirteenThreeWayCollarsMember_lbl" xml:lang="en-US" id="id_623015_616328_2_1">2013 Three-Way Collars [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_TwoThousandThirteenThreeWayCollarsMember" xlink:to="oas_TwoThousandThirteenThreeWayCollarsMember_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_TwoThousandThirteenTwoWayAndThreeWayCollarsMember" xlink:label="oas_TwoThousandThirteenTwoWayAndThreeWayCollarsMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_TwoThousandThirteenTwoWayAndThreeWayCollarsMember_lbl" xml:lang="en-US" id="id_623015_616329_3_1">Two Thousand Thirteen, Two-Way And Three-Way Collars [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_TwoThousandThirteenTwoWayAndThreeWayCollarsMember_lbl" xml:lang="en-US" id="id_623015_616329_1_1">Two Thousand Thirteen Two Way And Three Way Collars [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_TwoThousandThirteenTwoWayAndThreeWayCollarsMember_lbl" xml:lang="en-US" id="id_623015_616329_2_1">2013 Two-Way And Three-Way Collars [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_TwoThousandThirteenTwoWayAndThreeWayCollarsMember" xlink:to="oas_TwoThousandThirteenTwoWayAndThreeWayCollarsMember_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_TwoThousandThirteenTwoWayCollarsMember" xlink:label="oas_TwoThousandThirteenTwoWayCollarsMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_TwoThousandThirteenTwoWayCollarsMember_lbl" xml:lang="en-US" id="id_623015_616330_3_1">Two Thousand Thirteen, Two-Way Collars [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_TwoThousandThirteenTwoWayCollarsMember_lbl" xml:lang="en-US" id="id_623015_616330_1_1">Two Thousand Thirteen Two Way Collars [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_TwoThousandThirteenTwoWayCollarsMember_lbl" xml:lang="en-US" id="id_623015_616330_2_1">2013 Two-Way Collars [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_TwoThousandThirteenTwoWayCollarsMember" xlink:to="oas_TwoThousandThirteenTwoWayCollarsMember_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_TwoThousandTwelveSwapContractsMember" xlink:label="oas_TwoThousandTwelveSwapContractsMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_TwoThousandTwelveSwapContractsMember_lbl" xml:lang="en-US" id="id_623015_639180_3_1">Two Thousand Twelve Swap Contracts [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_TwoThousandTwelveSwapContractsMember_lbl" xml:lang="en-US" id="id_623015_639180_1_1">Two Thousand Twelve Swap Contracts [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_TwoThousandTwelveSwapContractsMember_lbl" xml:lang="en-US" id="id_623015_639180_2_1">Two Thousand Twelve Swap Contracts [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_TwoThousandTwelveSwapContractsMember" xlink:to="oas_TwoThousandTwelveSwapContractsMember_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_TwoThousandTwelveThreeWayCollarsMember" xlink:label="oas_TwoThousandTwelveThreeWayCollarsMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_TwoThousandTwelveThreeWayCollarsMember_lbl" xml:lang="en-US" id="id_623015_616337_3_1">Two Thousand Twelve, Three-Way Collars [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_TwoThousandTwelveThreeWayCollarsMember_lbl" xml:lang="en-US" id="id_623015_616337_1_1">Two Thousand Twelve Three Way Collars [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_TwoThousandTwelveThreeWayCollarsMember_lbl" xml:lang="en-US" id="id_623015_616337_2_1">2012 Three-Way Collars [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_TwoThousandTwelveThreeWayCollarsMember" xlink:to="oas_TwoThousandTwelveThreeWayCollarsMember_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_TwoThousandTwelveTwoWayAndThreeWayCollarsMember" xlink:label="oas_TwoThousandTwelveTwoWayAndThreeWayCollarsMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_TwoThousandTwelveTwoWayAndThreeWayCollarsMember_lbl" xml:lang="en-US" id="id_623015_616338_3_1">Two Thousand Twelve, Two-Way And Three-Way Collars [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_TwoThousandTwelveTwoWayAndThreeWayCollarsMember_lbl" xml:lang="en-US" id="id_623015_616338_1_1">Two Thousand Twelve Two Way And Three Way Collars [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_TwoThousandTwelveTwoWayAndThreeWayCollarsMember_lbl" xml:lang="en-US" id="id_623015_616338_2_1">2012 Two-Way And Three-Way Collars [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_TwoThousandTwelveTwoWayAndThreeWayCollarsMember" xlink:to="oas_TwoThousandTwelveTwoWayAndThreeWayCollarsMember_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_TwoThousandTwelveTwoWayCollarsMember" xlink:label="oas_TwoThousandTwelveTwoWayCollarsMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_TwoThousandTwelveTwoWayCollarsMember_lbl" xml:lang="en-US" id="id_623015_616339_3_1">Two Thousand Twelve, Two-Way Collars [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_TwoThousandTwelveTwoWayCollarsMember_lbl" xml:lang="en-US" id="id_623015_616339_1_1">Two Thousand Twelve Two Way Collars [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_TwoThousandTwelveTwoWayCollarsMember_lbl" xml:lang="en-US" id="id_623015_616339_2_1">2012 Two-Way Collars [Member]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="oas_TwoThousandTwelveTwoWayCollarsMember" xlink:to="oas_TwoThousandTwelveTwoWayCollarsMember_lbl"/>
    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_TwoThousandTwentyOneAndTwoThousandNineteenNotesMember" xlink:label="oas_TwoThousandTwentyOneAndTwoThousandNineteenNotesMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_TwoThousandTwentyOneAndTwoThousandNineteenNotesMember_lbl" xml:lang="en-US" id="id_623015_830644_3_1">Two Thousand Twenty One And Two Thousand Nineteen Notes [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_TwoThousandTwentyOneAndTwoThousandNineteenNotesMember_lbl" xml:lang="en-US" id="id_623015_830644_1_1">Two Thousand Twenty One And Two Thousand Nineteen Notes [Member]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_TwoThousandTwentyOneNotesMember_lbl" xml:lang="en-US" id="id_623015_616342_1_1">Two Thousand Twenty One Notes [Member]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_TwoThousandTwentyThreeNotesMember_lbl" xml:lang="en-US" id="id_623015_691833_1_1">Two Thousand Twenty Three Notes [Member]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_UnprovedOilAndGasPropertiesMember_lbl" xml:lang="en-US" id="id_623015_616387_3_1">Unproved Oil And Gas Properties [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_UnprovedOilAndGasPropertiesMember_lbl" xml:lang="en-US" id="id_623015_616387_1_1">Unproved Oil And Gas Properties [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_UnprovedOilAndGasPropertiesMember_lbl" xml:lang="en-US" id="id_623015_616387_2_1">Unproved Oil And Gas Properties [Member]</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_UnrealizedGainLossOnCommodityContracts" xlink:label="us-gaap_UnrealizedGainLossOnCommodityContracts"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_UnrealizedGainLossOnCommodityContracts_lbl" xml:lang="en-US" id="id_623015_566559_1_1">Unrealized Gain Loss On Commodity Contracts</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_UnrealizedGainLossOnCommodityContracts_lbl" xml:lang="en-US" id="id_623015_566559_2_1">Change in unrealized gain (loss) on derivative instruments</label>
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    <loc xlink:type="locator" xlink:href="oas-20120930.xsd#oas_UnsecuredSeniorNotesMember" xlink:label="oas_UnsecuredSeniorNotesMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_UnsecuredSeniorNotesMember_lbl" xml:lang="en-US" id="id_623015_589564_3_1">Unsecured Senior Notes [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_UnsecuredSeniorNotesMember_lbl" xml:lang="en-US" id="id_623015_589564_1_1">Unsecured Senior Notes [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_UnsecuredSeniorNotesMember_lbl" xml:lang="en-US" id="id_623015_589564_2_1">Unsecured Senior Notes [Member]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment_lbl" xml:lang="en-US" id="id_623015_575383_1_1">Weighted Average Number Diluted Shares Outstanding Adjustment</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment_lbl" xml:lang="en-US" id="id_623015_575383_2_1">Dilution effect of stock awards at end of period</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_lbl" xml:lang="en-US" id="id_623015_574868_1_1">Weighted Average Number Of Diluted Shares Outstanding</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_lbl" xml:lang="en-US" id="id_623015_574868_2_1">Diluted (Note 11)</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_lbl" xml:lang="en-US" id="id_623015_569192_1_1">Weighted Average Number Of Shares Outstanding [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_lbl" xml:lang="en-US" id="id_623015_569192_2_1">Weighted average shares outstanding:</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2012/elts/us-gaap-2012-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl" xml:lang="en-US" id="id_623015_567795_2_1">Basic (Note 11)</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_WeightedAverageNumberOfSharesOutstandingReconciliationLineItems_lbl" xml:lang="en-US" id="id_623015_637646_3_1">Weighted Average Number Of Shares Outstanding Reconciliation [Line Items]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="oas_WeightedAverageNumberOfSharesOutstandingReconciliationLineItems_lbl" xml:lang="en-US" id="id_623015_637646_2_1">Weighted Average Number Of Shares Outstanding Reconciliation [Line Items]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="oas_WillistonBasinProjectMember_lbl" xml:lang="en-US" id="id_623015_616406_3_1">Williston Basin Project [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="oas_WillistonBasinProjectMember_lbl" xml:lang="en-US" id="id_623015_616406_1_1">Williston Basin Project [Member]</label>
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