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    <link:label id="lab_sm_NYMEXOilCalendarMonthAverageRollDifferentialContractFourthQuarterYear1Member_e2a47dcc-b536-45d4-a3aa-940ecdf01075_terseLabel_en-US" xlink:label="lab_sm_NYMEXOilCalendarMonthAverageRollDifferentialContractFourthQuarterYear1Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">NYMEX Oil Calendar Month Average Roll Differential Fourth Quarter, Year 1</link:label>
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    <link:label id="lab_dei_EntityCurrentReportingStatus_a3c5ea55-cb20-4d6e-852d-b4990a555ea0_terseLabel_en-US" xlink:label="lab_dei_EntityCurrentReportingStatus" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Entity Current Reporting Status</link:label>
    <link:label id="lab_dei_EntityCurrentReportingStatus_label_en-US" xlink:label="lab_dei_EntityCurrentReportingStatus" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Entity Current Reporting Status</link:label>
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    <link:label id="lab_sm_NYMEXWTIICEBrentMember_3ce72813-2517-43c1-a42e-be5e92d5a343_terseLabel_en-US" xlink:label="lab_sm_NYMEXWTIICEBrentMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">NYMEX WTI ICE Brent [Member]</link:label>
    <link:label id="lab_sm_NYMEXWTIICEBrentMember_label_en-US" xlink:label="lab_sm_NYMEXWTIICEBrentMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">NYMEX WTI ICE Brent [Member]</link:label>
    <link:label id="lab_sm_NYMEXWTIICEBrentMember_documentation_en-US" xlink:label="lab_sm_NYMEXWTIICEBrentMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">NYMEX WTI ICE Brent [Member]</link:label>
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    <link:label id="lab_sm_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionValue_2517a26a-e925-4a58-9f94-b8b1443cdaba_terseLabel_en-US" xlink:label="lab_sm_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Maximum Employee Subscription Value</link:label>
    <link:label id="lab_sm_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionValue_label_en-US" xlink:label="lab_sm_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Maximum Employee Subscription Value</link:label>
    <link:label id="lab_sm_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionValue_documentation_en-US" xlink:label="lab_sm_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionValue" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Maximum Employee Subscription Value</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionValue" xlink:href="sm-20210930.xsd#sm_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionValue"/>
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    <link:label id="lab_us-gaap_RepaymentsOfConvertibleDebt_c747c8a7-77d7-46e0-954e-3274f6cb6f2e_terseLabel_en-US" xlink:label="lab_us-gaap_RepaymentsOfConvertibleDebt" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Repayment of 1.50% Senior Convertible Notes due 2021</link:label>
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    <link:label id="lab_sm_GasCollarContractFourthQuarterYear1Member_71f6de19-e5cd-49f5-a4df-e86cd020b5bc_terseLabel_en-US" xlink:label="lab_sm_GasCollarContractFourthQuarterYear1Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Gas Collar Contract, Fourth Quarter, Year 1</link:label>
    <link:label id="lab_sm_GasCollarContractFourthQuarterYear1Member_label_en-US" xlink:label="lab_sm_GasCollarContractFourthQuarterYear1Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Gas Collar Contract, Fourth Quarter, Year 1 [Member]</link:label>
    <link:label id="lab_sm_GasCollarContractFourthQuarterYear1Member_documentation_en-US" xlink:label="lab_sm_GasCollarContractFourthQuarterYear1Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Gas Collar Contract, Fourth Quarter, Year 1</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_sm_GasCollarContractFourthQuarterYear1Member" xlink:to="lab_sm_GasCollarContractFourthQuarterYear1Member" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OtherNoncashIncomeExpense_fde24f8f-fe01-4ff8-9ed2-b7154e59261d_negatedLabel_en-US" xlink:label="lab_us-gaap_OtherNoncashIncomeExpense" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other, net</link:label>
    <link:label id="lab_us-gaap_OtherNoncashIncomeExpense_label_en-US" xlink:label="lab_us-gaap_OtherNoncashIncomeExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other Noncash Income (Expense)</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherNoncashIncomeExpense" xlink:to="lab_us-gaap_OtherNoncashIncomeExpense" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DerivativeFairValueOfDerivativeAsset_507bd16f-8d5f-45f1-bb82-36a74e1a87d0_verboseLabel_en-US" xlink:label="lab_us-gaap_DerivativeFairValueOfDerivativeAsset" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Total derivative assets</link:label>
    <link:label id="lab_us-gaap_DerivativeFairValueOfDerivativeAsset_d47dcd7a-0bbf-4d80-884f-1f00993129c2_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeFairValueOfDerivativeAsset" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative Assets, Fair Value, Gross Asset</link:label>
    <link:label id="lab_us-gaap_DerivativeFairValueOfDerivativeAsset_label_en-US" xlink:label="lab_us-gaap_DerivativeFairValueOfDerivativeAsset" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative Asset, Fair Value, Gross Asset</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeAsset" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeFairValueOfDerivativeAsset"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeFairValueOfDerivativeAsset" xlink:to="lab_us-gaap_DerivativeFairValueOfDerivativeAsset" xlink:type="arc" order="1"/>
    <link:label id="lab_sm_DerivativeGasBasisSwapTypeWeightedAverageContractPrice_7a078a2f-34e9-4fe2-a16e-8bca1cb71e83_terseLabel_en-US" xlink:label="lab_sm_DerivativeGasBasisSwapTypeWeightedAverageContractPrice" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative, Gas Basis Swap Type, Weighted-Average Contract Price</link:label>
    <link:label id="lab_sm_DerivativeGasBasisSwapTypeWeightedAverageContractPrice_label_en-US" xlink:label="lab_sm_DerivativeGasBasisSwapTypeWeightedAverageContractPrice" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative, Gas Basis Swap Type, Weighted-Average Contract Price</link:label>
    <link:label id="lab_sm_DerivativeGasBasisSwapTypeWeightedAverageContractPrice_documentation_en-US" xlink:label="lab_sm_DerivativeGasBasisSwapTypeWeightedAverageContractPrice" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative, Gas Basis Swap Type, Weighted-Average Contract Price</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_DerivativeGasBasisSwapTypeWeightedAverageContractPrice" xlink:href="sm-20210930.xsd#sm_DerivativeGasBasisSwapTypeWeightedAverageContractPrice"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_sm_DerivativeGasBasisSwapTypeWeightedAverageContractPrice" xlink:to="lab_sm_DerivativeGasBasisSwapTypeWeightedAverageContractPrice" xlink:type="arc" order="1"/>
    <link:label id="lab_sm_NYMEXOilCollarContractFirstQuarterYear3Member_06ee0876-8a84-4c56-90fd-fb1583870161_terseLabel_en-US" xlink:label="lab_sm_NYMEXOilCollarContractFirstQuarterYear3Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">NYMEX Oil Collar Contract First Quarter, Year 3</link:label>
    <link:label id="lab_sm_NYMEXOilCollarContractFirstQuarterYear3Member_label_en-US" xlink:label="lab_sm_NYMEXOilCollarContractFirstQuarterYear3Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">NYMEX Oil Collar Contract First Quarter, Year 3 [Member]</link:label>
    <link:label id="lab_sm_NYMEXOilCollarContractFirstQuarterYear3Member_documentation_en-US" xlink:label="lab_sm_NYMEXOilCollarContractFirstQuarterYear3Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">NYMEX Oil Collar Contract First Quarter, Year 3</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_NYMEXOilCollarContractFirstQuarterYear3Member" xlink:href="sm-20210930.xsd#sm_NYMEXOilCollarContractFirstQuarterYear3Member"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_sm_NYMEXOilCollarContractFirstQuarterYear3Member" xlink:to="lab_sm_NYMEXOilCollarContractFirstQuarterYear3Member" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AssetsFairValueDisclosureAbstract_de7ff336-f414-413a-8a93-96b720a8d5e2_terseLabel_en-US" xlink:label="lab_us-gaap_AssetsFairValueDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Assets</link:label>
    <link:label id="lab_us-gaap_AssetsFairValueDisclosureAbstract_label_en-US" xlink:label="lab_us-gaap_AssetsFairValueDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Assets, Fair Value Disclosure [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AssetsFairValueDisclosureAbstract"/>
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    <link:label id="lab_us-gaap_DerivativeFloorPrice_a927c5b1-6aa4-4938-a316-478c8581d5e5_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeFloorPrice" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative, Weighted-Average Floor Price</link:label>
    <link:label id="lab_us-gaap_DerivativeFloorPrice_label_en-US" xlink:label="lab_us-gaap_DerivativeFloorPrice" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative, Floor Price</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFloorPrice" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeFloorPrice"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeFloorPrice" xlink:to="lab_us-gaap_DerivativeFloorPrice" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PlanNameAxis_b91b3579-315b-44a8-bc35-b4b5a6ad6198_terseLabel_en-US" xlink:label="lab_us-gaap_PlanNameAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Plan Name</link:label>
    <link:label id="lab_us-gaap_PlanNameAxis_label_en-US" xlink:label="lab_us-gaap_PlanNameAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Plan Name [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PlanNameAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PlanNameAxis" xlink:to="lab_us-gaap_PlanNameAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_sm_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodMultiplierAssumed_719a6d95-e31b-4f31-a9ed-fcf1a0e592a6_terseLabel_en-US" xlink:label="lab_sm_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodMultiplierAssumed" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Multiplier Assumed</link:label>
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    <link:label id="lab_sm_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodMultiplierAssumed_documentation_en-US" xlink:label="lab_sm_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodMultiplierAssumed" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Multiplier Assumed</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodMultiplierAssumed" xlink:href="sm-20210930.xsd#sm_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodMultiplierAssumed"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_sm_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodMultiplierAssumed" xlink:to="lab_sm_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodMultiplierAssumed" xlink:type="arc" order="1"/>
    <link:label id="lab_sm_AcceleratedUnamortizedDebtDiscountMember_92c62dbf-9fc0-490b-9ce7-1113fdf4de25_terseLabel_en-US" xlink:label="lab_sm_AcceleratedUnamortizedDebtDiscountMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Accelerated Unamortized Debt Discount</link:label>
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    <link:label id="lab_sm_AcceleratedUnamortizedDebtDiscountMember_documentation_en-US" xlink:label="lab_sm_AcceleratedUnamortizedDebtDiscountMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Accelerated Unamortized Debt Discount</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_AcceleratedUnamortizedDebtDiscountMember" xlink:href="sm-20210930.xsd#sm_AcceleratedUnamortizedDebtDiscountMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_sm_AcceleratedUnamortizedDebtDiscountMember" xlink:to="lab_sm_AcceleratedUnamortizedDebtDiscountMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LongTermDebt_bb59878f-5d6c-41d4-adf5-7a63f7d1084f_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebt" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Total long-term debt, net</link:label>
    <link:label id="lab_us-gaap_LongTermDebt_label_en-US" xlink:label="lab_us-gaap_LongTermDebt" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Long-term Debt</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebt"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongTermDebt" xlink:to="lab_us-gaap_LongTermDebt" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FairValueInputsLevel1Member_c0405f0b-5f71-4dd2-b548-bf446fe33758_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueInputsLevel1Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Fair Value, Inputs, Level 1</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_FairValueInputsLevel1Member" xlink:to="lab_us-gaap_FairValueInputsLevel1Member" xlink:type="arc" order="1"/>
    <link:label id="lab_sm_MultiplierAppliedToPsuAwardsAtSettlement_f9ff5bd5-a310-461b-ab3e-b9868f37bbe1_terseLabel_en-US" xlink:label="lab_sm_MultiplierAppliedToPsuAwardsAtSettlement" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Multiplier applied to PSU awards at settlement</link:label>
    <link:label id="lab_sm_MultiplierAppliedToPsuAwardsAtSettlement_label_en-US" xlink:label="lab_sm_MultiplierAppliedToPsuAwardsAtSettlement" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Multiplier Applied to PSU Awards at Settlement</link:label>
    <link:label id="lab_sm_MultiplierAppliedToPsuAwardsAtSettlement_documentation_en-US" xlink:label="lab_sm_MultiplierAppliedToPsuAwardsAtSettlement" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">The multiplier applied to the PSU awards at settlement to determine the number of shares of the Company&#8217;s common stock to be issued at the completion of the performance period.</link:label>
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    <link:label id="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_73cbd22d-3145-4f99-a366-ad9be4d559cc_terseLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Cash flows from investing activities:</link:label>
    <link:label id="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_label_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Net Cash Provided by (Used in) Investing Activities [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:to="lab_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_sm_DrillingRigLeasingContractsMember_bbe73eb5-1d86-43b5-a891-fb5c68c9cd82_terseLabel_en-US" xlink:label="lab_sm_DrillingRigLeasingContractsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Drilling Rig Leasing Contracts</link:label>
    <link:label id="lab_sm_DrillingRigLeasingContractsMember_label_en-US" xlink:label="lab_sm_DrillingRigLeasingContractsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Drilling Rig Leasing Contracts [Member]</link:label>
    <link:label id="lab_sm_DrillingRigLeasingContractsMember_documentation_en-US" xlink:label="lab_sm_DrillingRigLeasingContractsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Drilling Rig Leasing Contracts [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_DrillingRigLeasingContractsMember" xlink:href="sm-20210930.xsd#sm_DrillingRigLeasingContractsMember"/>
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    <link:label id="lab_dei_DocumentTransitionReport_d9c86628-b434-49c9-a026-99e505fafbee_terseLabel_en-US" xlink:label="lab_dei_DocumentTransitionReport" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Document Transition Report</link:label>
    <link:label id="lab_dei_DocumentTransitionReport_label_en-US" xlink:label="lab_dei_DocumentTransitionReport" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Document Transition Report</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentTransitionReport" xlink:href="https://xbrl.sec.gov/dei/2021/dei-2021.xsd#dei_DocumentTransitionReport"/>
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    <link:label id="lab_us-gaap_IncomeTaxDisclosureAbstract_34a83c0e-e653-4529-aae1-c7e99d7718a7_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeTaxDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Income Tax Disclosure [Abstract]</link:label>
    <link:label id="lab_us-gaap_IncomeTaxDisclosureAbstract_label_en-US" xlink:label="lab_us-gaap_IncomeTaxDisclosureAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Income Tax Disclosure [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxDisclosureAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxDisclosureAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract" xlink:to="lab_us-gaap_IncomeTaxDisclosureAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LiabilitiesAndStockholdersEquity_cf78dffd-90b2-47bf-b621-da5ec872d39f_totalLabel_en-US" xlink:label="lab_us-gaap_LiabilitiesAndStockholdersEquity" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Total liabilities and stockholders&#8217; equity</link:label>
    <link:label id="lab_us-gaap_LiabilitiesAndStockholdersEquity_label_en-US" xlink:label="lab_us-gaap_LiabilitiesAndStockholdersEquity" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Liabilities and Equity</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="lab_us-gaap_LiabilitiesAndStockholdersEquity" xlink:type="arc" order="1"/>
    <link:label id="lab_sm_A6625SeniorUnsecuredNotesDue2027Member_9ec24a68-721c-4a55-9947-07fe15441105_terseLabel_en-US" xlink:label="lab_sm_A6625SeniorUnsecuredNotesDue2027Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">6.625% Senior Unsecured Notes due 2027</link:label>
    <link:label id="lab_sm_A6625SeniorUnsecuredNotesDue2027Member_label_en-US" xlink:label="lab_sm_A6625SeniorUnsecuredNotesDue2027Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">6.625% Senior Unsecured Notes Due 2027 [Member]</link:label>
    <link:label id="lab_sm_A6625SeniorUnsecuredNotesDue2027Member_documentation_en-US" xlink:label="lab_sm_A6625SeniorUnsecuredNotesDue2027Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">6.625% Senior Unsecured Notes Due 2027 [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_A6625SeniorUnsecuredNotesDue2027Member" xlink:href="sm-20210930.xsd#sm_A6625SeniorUnsecuredNotesDue2027Member"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_sm_A6625SeniorUnsecuredNotesDue2027Member" xlink:to="lab_sm_A6625SeniorUnsecuredNotesDue2027Member" xlink:type="arc" order="1"/>
    <link:label id="lab_sm_GasSwapsContractYear2Member_636083ea-ca10-403c-9602-78fc9ee31960_terseLabel_en-US" xlink:label="lab_sm_GasSwapsContractYear2Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Gas Swaps Contract, Year 2</link:label>
    <link:label id="lab_sm_GasSwapsContractYear2Member_label_en-US" xlink:label="lab_sm_GasSwapsContractYear2Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Gas Swaps Contract, Year 2 [Member]</link:label>
    <link:label id="lab_sm_GasSwapsContractYear2Member_documentation_en-US" xlink:label="lab_sm_GasSwapsContractYear2Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Gas Swaps Contract, Year 2 [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_GasSwapsContractYear2Member" xlink:href="sm-20210930.xsd#sm_GasSwapsContractYear2Member"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_sm_GasSwapsContractYear2Member" xlink:to="lab_sm_GasSwapsContractYear2Member" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DerivativeLiabilityFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElection_97924787-b294-4b04-8c59-d0a7a9f8db10_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_DerivativeLiabilityFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElection" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative liabilities, fair value, net amounts</link:label>
    <link:label id="lab_us-gaap_DerivativeLiabilityFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElection_label_en-US" xlink:label="lab_us-gaap_DerivativeLiabilityFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElection" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative Liability, Fair Value, Offset Against Collateral, Net of Not Subject to Master Netting Arrangement, Policy Election</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElection" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeLiabilityFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElection"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeLiabilityFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElection" xlink:to="lab_us-gaap_DerivativeLiabilityFairValueOffsetAgainstCollateralNetOfNotSubjectToMasterNettingArrangementPolicyElection" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OilAndGasPropertiesMember_7175e031-0fb5-479b-8cf7-50c57d92ec82_terseLabel_en-US" xlink:label="lab_us-gaap_OilAndGasPropertiesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Oil and Gas Properties</link:label>
    <link:label id="lab_us-gaap_OilAndGasPropertiesMember_label_en-US" xlink:label="lab_us-gaap_OilAndGasPropertiesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Oil and Gas Properties [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OilAndGasPropertiesMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OilAndGasPropertiesMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OilAndGasPropertiesMember" xlink:to="lab_us-gaap_OilAndGasPropertiesMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ProceedsFromIssuanceOfLongTermDebtAndCapitalSecuritiesNet_248dda1c-e0d2-4e5b-8ee1-93be6ddd9034_terseLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromIssuanceOfLongTermDebtAndCapitalSecuritiesNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Net proceeds from Senior Notes</link:label>
    <link:label id="lab_us-gaap_ProceedsFromIssuanceOfLongTermDebtAndCapitalSecuritiesNet_label_en-US" xlink:label="lab_us-gaap_ProceedsFromIssuanceOfLongTermDebtAndCapitalSecuritiesNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Proceeds from Issuance of Long-term Debt and Capital Securities, Net</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebtAndCapitalSecuritiesNet" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromIssuanceOfLongTermDebtAndCapitalSecuritiesNet"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebtAndCapitalSecuritiesNet" xlink:to="lab_us-gaap_ProceedsFromIssuanceOfLongTermDebtAndCapitalSecuritiesNet" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LiabilitiesAndStockholdersEquityAbstract_f7100496-06fc-416c-a967-0fccc38de618_terseLabel_en-US" xlink:label="lab_us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">LIABILITIES AND STOCKHOLDERS&#8217; EQUITY</link:label>
    <link:label id="lab_us-gaap_LiabilitiesAndStockholdersEquityAbstract_label_en-US" xlink:label="lab_us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Liabilities and Equity [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:to="lab_us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DerivativeLineItems_3142ab50-20ab-41a3-9c21-ff3bffc91ae8_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative Financial Instruments</link:label>
    <link:label id="lab_us-gaap_DerivativeLineItems_label_en-US" xlink:label="lab_us-gaap_DerivativeLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeLineItems" xlink:to="lab_us-gaap_DerivativeLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentNetAbstract_9928e382-b905-4d25-ac65-33767b766bab_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentNetAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Property and equipment (successful efforts method):</link:label>
    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentNetAbstract_label_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentNetAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Property, Plant and Equipment, Net [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNetAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNetAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentNetAbstract" xlink:to="lab_us-gaap_PropertyPlantAndEquipmentNetAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent_237a5022-e610-442a-b229-ba635ef2d33d_terseLabel_en-US" xlink:label="lab_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Accounts payable and accrued expenses</link:label>
    <link:label id="lab_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent_label_en-US" xlink:label="lab_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Accounts Payable and Accrued Liabilities, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent" xlink:to="lab_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract_095fee22-25ac-421a-8a78-c1c985996936_terseLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Cash flows from operating activities:</link:label>
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    <link:label id="lab_us-gaap_EarningsPerShareTextBlock_df3a04aa-8e68-4f5e-9165-2985f897f6bd_terseLabel_en-US" xlink:label="lab_us-gaap_EarningsPerShareTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Earnings Per Share [Text Block]</link:label>
    <link:label id="lab_us-gaap_EarningsPerShareTextBlock_label_en-US" xlink:label="lab_us-gaap_EarningsPerShareTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Earnings Per Share [Text Block]</link:label>
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    <link:label id="lab_us-gaap_DerivativeLiabilitiesCurrent_fd89a161-9ea0-4536-b6a6-a21b7ba689c9_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeLiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative liabilities</link:label>
    <link:label id="lab_us-gaap_DerivativeLiabilitiesCurrent_b2644b55-e9cd-4d5a-bf06-3da1676ef0f3_verboseLabel_en-US" xlink:label="lab_us-gaap_DerivativeLiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative liabilities, current</link:label>
    <link:label id="lab_us-gaap_DerivativeLiabilitiesCurrent_label_en-US" xlink:label="lab_us-gaap_DerivativeLiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative Liability, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilitiesCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeLiabilitiesCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeLiabilitiesCurrent" xlink:to="lab_us-gaap_DerivativeLiabilitiesCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_srt_MinimumMember_938d52c4-5758-4ad8-a23c-2eb6ba0907f3_terseLabel_en-US" xlink:label="lab_srt_MinimumMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Minimum</link:label>
    <link:label id="lab_srt_MinimumMember_label_en-US" xlink:label="lab_srt_MinimumMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Minimum [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MinimumMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_MinimumMember" xlink:to="lab_srt_MinimumMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ClassOfWarrantOrRightLineItems_91a2d58d-4bfb-493c-96be-51c3ee06db7d_terseLabel_en-US" xlink:label="lab_us-gaap_ClassOfWarrantOrRightLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Class of Warrant or Right [Line Items]</link:label>
    <link:label id="lab_us-gaap_ClassOfWarrantOrRightLineItems_label_en-US" xlink:label="lab_us-gaap_ClassOfWarrantOrRightLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Class of Warrant or Right [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfWarrantOrRightLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ClassOfWarrantOrRightLineItems" xlink:to="lab_us-gaap_ClassOfWarrantOrRightLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_sm_NYMEXOilCollarContractYear2Member_8b6129fd-e007-4a25-82b4-6db27164d5b5_terseLabel_en-US" xlink:label="lab_sm_NYMEXOilCollarContractYear2Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">NYMEX Oil Collar Contract, Year 2</link:label>
    <link:label id="lab_sm_NYMEXOilCollarContractYear2Member_label_en-US" xlink:label="lab_sm_NYMEXOilCollarContractYear2Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">NYMEX Oil Collar Contract, Year 2 [Member]</link:label>
    <link:label id="lab_sm_NYMEXOilCollarContractYear2Member_documentation_en-US" xlink:label="lab_sm_NYMEXOilCollarContractYear2Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">NYMEX Oil Collar Contract, Year 2 [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_NYMEXOilCollarContractYear2Member" xlink:href="sm-20210930.xsd#sm_NYMEXOilCollarContractYear2Member"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_sm_NYMEXOilCollarContractYear2Member" xlink:to="lab_sm_NYMEXOilCollarContractYear2Member" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract_3c54349a-b25e-42d1-960f-fecac68dbcf5_terseLabel_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other comprehensive income, net of tax:</link:label>
    <link:label id="lab_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract_label_en-US" xlink:label="lab_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract" xlink:to="lab_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_sm_OilBasisSwapContractYear2Member_2db5b8d4-b782-408f-af32-8f2f49786938_terseLabel_en-US" xlink:label="lab_sm_OilBasisSwapContractYear2Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Oil Basis Swap Contract, Year 2</link:label>
    <link:label id="lab_sm_OilBasisSwapContractYear2Member_label_en-US" xlink:label="lab_sm_OilBasisSwapContractYear2Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Oil Basis Swap Contract, Year 2 [Member]</link:label>
    <link:label id="lab_sm_OilBasisSwapContractYear2Member_documentation_en-US" xlink:label="lab_sm_OilBasisSwapContractYear2Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Oil Basis Swap Contract, Year 2 [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_OilBasisSwapContractYear2Member" xlink:href="sm-20210930.xsd#sm_OilBasisSwapContractYear2Member"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_sm_OilBasisSwapContractYear2Member" xlink:to="lab_sm_OilBasisSwapContractYear2Member" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DerivativeAssetsCurrent_93a19d9b-2115-4d21-aa6f-21b14ccb9a7e_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeAssetsCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative assets</link:label>
    <link:label id="lab_us-gaap_DerivativeAssetsCurrent_469768b2-1947-4178-861d-0beca5781dc7_verboseLabel_en-US" xlink:label="lab_us-gaap_DerivativeAssetsCurrent" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative assets, current</link:label>
    <link:label id="lab_us-gaap_DerivativeAssetsCurrent_label_en-US" xlink:label="lab_us-gaap_DerivativeAssetsCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative Asset, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetsCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeAssetsCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeAssetsCurrent" xlink:to="lab_us-gaap_DerivativeAssetsCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_sm_DerivativeCalendarMonthAverageRollDifferentialSwapTypeWeightedAverageContractPrice_fd33d4f2-0d13-4b60-853e-257ba0d7e3a2_terseLabel_en-US" xlink:label="lab_sm_DerivativeCalendarMonthAverageRollDifferentialSwapTypeWeightedAverageContractPrice" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative, Roll Differential Swap Type, Weighted-Average Contract Price</link:label>
    <link:label id="lab_sm_DerivativeCalendarMonthAverageRollDifferentialSwapTypeWeightedAverageContractPrice_label_en-US" xlink:label="lab_sm_DerivativeCalendarMonthAverageRollDifferentialSwapTypeWeightedAverageContractPrice" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative, Calendar Month Average Roll Differential Swap Type, Weighted-Average Contract Price</link:label>
    <link:label id="lab_sm_DerivativeCalendarMonthAverageRollDifferentialSwapTypeWeightedAverageContractPrice_documentation_en-US" xlink:label="lab_sm_DerivativeCalendarMonthAverageRollDifferentialSwapTypeWeightedAverageContractPrice" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative, Calendar Month Average Roll Differential Swap Type, Weighted-Average Contract Price</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_DerivativeCalendarMonthAverageRollDifferentialSwapTypeWeightedAverageContractPrice" xlink:href="sm-20210930.xsd#sm_DerivativeCalendarMonthAverageRollDifferentialSwapTypeWeightedAverageContractPrice"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_sm_DerivativeCalendarMonthAverageRollDifferentialSwapTypeWeightedAverageContractPrice" xlink:to="lab_sm_DerivativeCalendarMonthAverageRollDifferentialSwapTypeWeightedAverageContractPrice" xlink:type="arc" order="1"/>
    <link:label id="lab_sm_OperatingLeaseMember_b7ee2210-4ed3-438c-94ab-17ed7466bcfe_terseLabel_en-US" xlink:label="lab_sm_OperatingLeaseMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Operating Lease</link:label>
    <link:label id="lab_sm_OperatingLeaseMember_label_en-US" xlink:label="lab_sm_OperatingLeaseMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Operating Lease [Member]</link:label>
    <link:label id="lab_sm_OperatingLeaseMember_documentation_en-US" xlink:label="lab_sm_OperatingLeaseMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Operating Lease</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_OperatingLeaseMember" xlink:href="sm-20210930.xsd#sm_OperatingLeaseMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_sm_OperatingLeaseMember" xlink:to="lab_sm_OperatingLeaseMember" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_TradingSymbol_80ff8ad2-72ae-4265-8397-1b658ced3381_terseLabel_en-US" xlink:label="lab_dei_TradingSymbol" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Trading Symbol</link:label>
    <link:label id="lab_dei_TradingSymbol_label_en-US" xlink:label="lab_dei_TradingSymbol" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Trading Symbol</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol" xlink:href="https://xbrl.sec.gov/dei/2021/dei-2021.xsd#dei_TradingSymbol"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_TradingSymbol" xlink:to="lab_dei_TradingSymbol" xlink:type="arc" order="1"/>
    <link:label id="lab_sm_ScheduleOfLongTermDebtInstrumentsSecuredTableTextBlock_2ce1801f-ed5a-48da-938f-fa28875e22d6_terseLabel_en-US" xlink:label="lab_sm_ScheduleOfLongTermDebtInstrumentsSecuredTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Schedule Of Long-term Debt Instruments, Senior Secured Notes [Table Text Block]</link:label>
    <link:label id="lab_sm_ScheduleOfLongTermDebtInstrumentsSecuredTableTextBlock_label_en-US" xlink:label="lab_sm_ScheduleOfLongTermDebtInstrumentsSecuredTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Schedule Of Long-term Debt Instruments, Secured [Table Text Block]</link:label>
    <link:label id="lab_sm_ScheduleOfLongTermDebtInstrumentsSecuredTableTextBlock_documentation_en-US" xlink:label="lab_sm_ScheduleOfLongTermDebtInstrumentsSecuredTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Schedule Of Long-term Debt Instruments, Secured [Table Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_ScheduleOfLongTermDebtInstrumentsSecuredTableTextBlock" xlink:href="sm-20210930.xsd#sm_ScheduleOfLongTermDebtInstrumentsSecuredTableTextBlock"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_sm_ScheduleOfLongTermDebtInstrumentsSecuredTableTextBlock" xlink:to="lab_sm_ScheduleOfLongTermDebtInstrumentsSecuredTableTextBlock" xlink:type="arc" order="1"/>
    <link:label id="lab_sm_DerivativeUnderlyingIndexAxis_91c964cb-d545-445a-92d9-a33ece43a50d_terseLabel_en-US" xlink:label="lab_sm_DerivativeUnderlyingIndexAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative Underlying Index [Axis]</link:label>
    <link:label id="lab_sm_DerivativeUnderlyingIndexAxis_label_en-US" xlink:label="lab_sm_DerivativeUnderlyingIndexAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative Underlying Index [Axis]</link:label>
    <link:label id="lab_sm_DerivativeUnderlyingIndexAxis_documentation_en-US" xlink:label="lab_sm_DerivativeUnderlyingIndexAxis" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative Underlying Index [Axis]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_DerivativeUnderlyingIndexAxis" xlink:href="sm-20210930.xsd#sm_DerivativeUnderlyingIndexAxis"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_sm_DerivativeUnderlyingIndexAxis" xlink:to="lab_sm_DerivativeUnderlyingIndexAxis" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LiabilitiesCurrentAbstract_ff38e909-3953-40b7-975e-99cc576cb075_terseLabel_en-US" xlink:label="lab_us-gaap_LiabilitiesCurrentAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Current liabilities:</link:label>
    <link:label id="lab_us-gaap_LiabilitiesCurrentAbstract_label_en-US" xlink:label="lab_us-gaap_LiabilitiesCurrentAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Liabilities, Current [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrentAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LiabilitiesCurrentAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract" xlink:to="lab_us-gaap_LiabilitiesCurrentAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ClassOfWarrantOrRightTable_5d7bcba9-e3e9-4f5f-8616-4d0dd11c70f0_terseLabel_en-US" xlink:label="lab_us-gaap_ClassOfWarrantOrRightTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Class of Warrant or Right [Table]</link:label>
    <link:label id="lab_us-gaap_ClassOfWarrantOrRightTable_label_en-US" xlink:label="lab_us-gaap_ClassOfWarrantOrRightTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Class of Warrant or Right [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightTable" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfWarrantOrRightTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ClassOfWarrantOrRightTable" xlink:to="lab_us-gaap_ClassOfWarrantOrRightTable" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ReceivableTypeDomain_6e1cdc43-4d5b-4dc0-b25b-165e1176781e_terseLabel_en-US" xlink:label="lab_us-gaap_ReceivableTypeDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Receivable Type [Domain]</link:label>
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    <link:label id="lab_us-gaap_AccountingPoliciesAbstract_ab0d2803-f359-488a-aba4-abbc88f8f80d_terseLabel_en-US" xlink:label="lab_us-gaap_AccountingPoliciesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Accounting Policies [Abstract]</link:label>
    <link:label id="lab_us-gaap_AccountingPoliciesAbstract_label_en-US" xlink:label="lab_us-gaap_AccountingPoliciesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Accounting Policies [Abstract]</link:label>
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    <link:label id="lab_us-gaap_ContractualObligation_4f62ea7c-936b-41a4-845b-59bae3c3667e_terseLabel_en-US" xlink:label="lab_us-gaap_ContractualObligation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Contractual Obligation</link:label>
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    <link:label id="lab_us-gaap_LettersOfCreditOutstandingAmount_a41e91e1-98cd-4685-88a2-c6c0146c437c_terseLabel_en-US" xlink:label="lab_us-gaap_LettersOfCreditOutstandingAmount" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Letters of credit</link:label>
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    <link:label id="lab_us-gaap_CurrentFederalTaxExpenseBenefit_b8c4eab6-d838-4b77-b25c-244021b45425_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_CurrentFederalTaxExpenseBenefit" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Federal</link:label>
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    <link:label id="lab_us-gaap_CommonStockValue_2da7e644-ea16-4b0a-9dd9-2b4b250ca84e_terseLabel_en-US" xlink:label="lab_us-gaap_CommonStockValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Common stock, $0.01 par value - authorized: 200,000,000 shares; issued and outstanding: 121,473,790 and 114,742,304 shares, respectively</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingencies" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommitmentsAndContingencies"/>
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    <link:label id="lab_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_e4104c6d-3314-4e63-ac85-95d11f9c8898_terseLabel_en-US" xlink:label="lab_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Accumulated other comprehensive loss</link:label>
    <link:label id="lab_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_label_en-US" xlink:label="lab_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Accumulated Other Comprehensive Income (Loss), Net of Tax</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
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    <link:label id="lab_us-gaap_ProceedsFromDebtNetOfIssuanceCosts_a69ac32f-26b6-4d09-b892-dd0a906707c4_terseLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromDebtNetOfIssuanceCosts" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Proceeds from Debt, Net of Issuance Costs</link:label>
    <link:label id="lab_us-gaap_ProceedsFromDebtNetOfIssuanceCosts_label_en-US" xlink:label="lab_us-gaap_ProceedsFromDebtNetOfIssuanceCosts" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Proceeds from Debt, Net of Issuance Costs</link:label>
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    <link:label id="lab_us-gaap_CompensationAndEmployeeBenefitPlansTextBlock_e12c467b-d963-44da-a793-44accae0ca4d_terseLabel_en-US" xlink:label="lab_us-gaap_CompensationAndEmployeeBenefitPlansTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Compensation Plans</link:label>
    <link:label id="lab_us-gaap_CompensationAndEmployeeBenefitPlansTextBlock_label_en-US" xlink:label="lab_us-gaap_CompensationAndEmployeeBenefitPlansTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Compensation and Employee Benefit Plans [Text Block]</link:label>
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    <link:label id="lab_us-gaap_PaymentsOfDebtIssuanceCosts_03d554f0-a479-456a-8fb4-3d3331f90e97_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_PaymentsOfDebtIssuanceCosts" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Debt issuance costs related to 10.0% Senior Secured Notes due 2025</link:label>
    <link:label id="lab_us-gaap_PaymentsOfDebtIssuanceCosts_label_en-US" xlink:label="lab_us-gaap_PaymentsOfDebtIssuanceCosts" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Payments of Debt Issuance Costs</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDebtIssuanceCosts" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsOfDebtIssuanceCosts"/>
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    <link:label id="lab_us-gaap_DebtInstrumentMaturityDate_d7d9020b-c57f-4cd3-917d-6689e8ff4100_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentMaturityDate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Debt Instrument, Maturity Date</link:label>
    <link:label id="lab_us-gaap_DebtInstrumentMaturityDate_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentMaturityDate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Debt Instrument, Maturity Date</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentMaturityDate" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentMaturityDate"/>
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    <link:label id="lab_dei_DocumentPeriodEndDate_5d7c31db-194b-4a98-a006-cf4ef5d82b59_terseLabel_en-US" xlink:label="lab_dei_DocumentPeriodEndDate" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Document Period End Date</link:label>
    <link:label id="lab_dei_DocumentPeriodEndDate_label_en-US" xlink:label="lab_dei_DocumentPeriodEndDate" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Document Period End Date</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate" xlink:href="https://xbrl.sec.gov/dei/2021/dei-2021.xsd#dei_DocumentPeriodEndDate"/>
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    <link:label id="lab_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_bccf4e5b-c4ce-4278-a83e-301891e28124_terseLabel_en-US" xlink:label="lab_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Dilutive effect of non-vested RSUs and contingent PSUs</link:label>
    <link:label id="lab_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_label_en-US" xlink:label="lab_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements"/>
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    <link:label id="lab_us-gaap_CostsAndExpenses_5cac2783-2285-4eac-a381-40168aab2e61_totalLabel_en-US" xlink:label="lab_us-gaap_CostsAndExpenses" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Total operating expenses</link:label>
    <link:label id="lab_us-gaap_CostsAndExpenses_label_en-US" xlink:label="lab_us-gaap_CostsAndExpenses" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Costs and Expenses</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostsAndExpenses" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CostsAndExpenses"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CostsAndExpenses" xlink:to="lab_us-gaap_CostsAndExpenses" xlink:type="arc" order="1"/>
    <link:label id="lab_sm_OilBasisSwapContractYear3Member_5502aeb2-9e5c-4cab-a298-f3f289e1f05b_terseLabel_en-US" xlink:label="lab_sm_OilBasisSwapContractYear3Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Oil Basis Swap Contract, Year 3</link:label>
    <link:label id="lab_sm_OilBasisSwapContractYear3Member_label_en-US" xlink:label="lab_sm_OilBasisSwapContractYear3Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Oil Basis Swap Contract, Year 3 [Member]</link:label>
    <link:label id="lab_sm_OilBasisSwapContractYear3Member_documentation_en-US" xlink:label="lab_sm_OilBasisSwapContractYear3Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Oil Basis Swap Contract, Year 3 [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_OilBasisSwapContractYear3Member" xlink:href="sm-20210930.xsd#sm_OilBasisSwapContractYear3Member"/>
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    <link:label id="lab_dei_EntityRegistrantName_acdf699c-630c-4e3a-96fe-e488d036d0b2_terseLabel_en-US" xlink:label="lab_dei_EntityRegistrantName" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Entity Registrant Name</link:label>
    <link:label id="lab_dei_EntityRegistrantName_label_en-US" xlink:label="lab_dei_EntityRegistrantName" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Entity Registrant Name</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName" xlink:href="https://xbrl.sec.gov/dei/2021/dei-2021.xsd#dei_EntityRegistrantName"/>
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    <link:label id="lab_sm_NYMEXOilCollarContractYear3Member_bead82b0-76af-42d0-a8b3-f57d91767d54_terseLabel_en-US" xlink:label="lab_sm_NYMEXOilCollarContractYear3Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">NYMEX Oil Collar Contract, Year 3</link:label>
    <link:label id="lab_sm_NYMEXOilCollarContractYear3Member_label_en-US" xlink:label="lab_sm_NYMEXOilCollarContractYear3Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">NYMEX Oil Collar Contract, Year 3 [Member]</link:label>
    <link:label id="lab_sm_NYMEXOilCollarContractYear3Member_documentation_en-US" xlink:label="lab_sm_NYMEXOilCollarContractYear3Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">NYMEX Oil Collar Contract, Year 3</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_NYMEXOilCollarContractYear3Member" xlink:href="sm-20210930.xsd#sm_NYMEXOilCollarContractYear3Member"/>
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    <link:label id="lab_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_0226b616-2fcb-4cf0-a713-2b8f166e4bcd_terseLabel_en-US" xlink:label="lab_us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Prepaid expenses and other</link:label>
    <link:label id="lab_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_label_en-US" xlink:label="lab_us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Prepaid Expense and Other Assets, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:to="lab_us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_sm_OilContractsMember_17ad0606-0bce-445d-944d-b077173e234f_terseLabel_en-US" xlink:label="lab_sm_OilContractsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Oil Contracts [Member]</link:label>
    <link:label id="lab_sm_OilContractsMember_label_en-US" xlink:label="lab_sm_OilContractsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Oil Contracts [Member]</link:label>
    <link:label id="lab_sm_OilContractsMember_documentation_en-US" xlink:label="lab_sm_OilContractsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Oil Contracts [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_OilContractsMember" xlink:href="sm-20210930.xsd#sm_OilContractsMember"/>
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    <link:label id="lab_us-gaap_CommonStockDividendsPerShareDeclared_89f3916c-35d5-40c5-90c2-8e9ef5aeac52_terseLabel_en-US" xlink:label="lab_us-gaap_CommonStockDividendsPerShareDeclared" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Dividends per common share</link:label>
    <link:label id="lab_us-gaap_CommonStockDividendsPerShareDeclared_a9997b1f-6ab5-4be9-83f1-02ef4091ddf7_verboseLabel_en-US" xlink:label="lab_us-gaap_CommonStockDividendsPerShareDeclared" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Cash dividends declared per share</link:label>
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    <link:label id="lab_us-gaap_FairValueByFairValueHierarchyLevelAxis_6e9ae0a8-f3e8-434e-abaf-27bae3e1734e_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Fair Value Hierarchy and NAV [Axis]</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
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    <link:label id="lab_us-gaap_EquityAbstract_label_en-US" xlink:label="lab_us-gaap_EquityAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Equity [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityAbstract"/>
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    <link:label id="lab_us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_label_en-US" xlink:label="lab_us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Class of Warrant or Right, Number of Securities Called by Warrants or Rights</link:label>
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    <link:label id="lab_us-gaap_OtherNonoperatingIncomeExpense_a76a7c40-487d-4bb0-9174-b9c891a9175b_terseLabel_en-US" xlink:label="lab_us-gaap_OtherNonoperatingIncomeExpense" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other non-operating income (expense), net</link:label>
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    <link:label id="lab_us-gaap_LongTermDebtFairValue_9ebe30c7-8908-48bf-b882-632fb76b77df_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermDebtFairValue" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Long-term Debt, Fair Value</link:label>
    <link:label id="lab_us-gaap_LongTermDebtFairValue_label_en-US" xlink:label="lab_us-gaap_LongTermDebtFairValue" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Long-term Debt, Fair Value</link:label>
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    <link:label id="lab_us-gaap_DebtInstrumentCovenantCompliance_436051cd-8506-4253-ac2b-2d18e708ae2d_terseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentCovenantCompliance" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Debt Instrument, Covenant Compliance</link:label>
    <link:label id="lab_us-gaap_DebtInstrumentCovenantCompliance_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentCovenantCompliance" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Debt Instrument, Covenant Compliance</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCovenantCompliance" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentCovenantCompliance"/>
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    <link:label id="lab_sm_OPISPropaneMontBelvieuNonTETMember_d521c226-6b9d-4160-9dfd-c82319ee094b_terseLabel_en-US" xlink:label="lab_sm_OPISPropaneMontBelvieuNonTETMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">OPIS Propane Mont Belvieu Non-TET [Member]</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_sm_OPISPropaneMontBelvieuNonTETMember" xlink:href="sm-20210930.xsd#sm_OPISPropaneMontBelvieuNonTETMember"/>
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    <link:label id="lab_us-gaap_OtherLiabilitiesCurrent_0b9b463c-cd9e-4df4-8e70-2dc5f8d04268_terseLabel_en-US" xlink:label="lab_us-gaap_OtherLiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other current liabilities</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherLiabilitiesCurrent" xlink:to="lab_us-gaap_OtherLiabilitiesCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DerivativeFairValueOfDerivativeNet_4a014eff-b96e-4a28-ba49-8d2504a403b0_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeFairValueOfDerivativeNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative, fair value, net</link:label>
    <link:label id="lab_us-gaap_DerivativeFairValueOfDerivativeNet_label_en-US" xlink:label="lab_us-gaap_DerivativeFairValueOfDerivativeNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative, Fair Value, Net</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeNet" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeFairValueOfDerivativeNet"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeFairValueOfDerivativeNet" xlink:to="lab_us-gaap_DerivativeFairValueOfDerivativeNet" xlink:type="arc" order="1"/>
    <link:label id="lab_srt_MaximumMember_86877adf-6e0d-41fd-9926-7b91ea176654_terseLabel_en-US" xlink:label="lab_srt_MaximumMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Maximum</link:label>
    <link:label id="lab_srt_MaximumMember_label_en-US" xlink:label="lab_srt_MaximumMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Maximum [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MaximumMember"/>
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    <link:label id="lab_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_adc37dcf-c32d-442e-90ef-81bea7705b73_terseLabel_en-US" xlink:label="lab_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Share-based Payment Arrangement [Abstract]</link:label>
    <link:label id="lab_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_label_en-US" xlink:label="lab_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Share-based Payment Arrangement [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract"/>
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    <link:label id="lab_us-gaap_ComponentsOfIncomeTaxExpenseBenefitContinuingOperationsAbstract_dbed942f-50d0-4359-91f6-2ff5f18f7645_terseLabel_en-US" xlink:label="lab_us-gaap_ComponentsOfIncomeTaxExpenseBenefitContinuingOperationsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Components of the provision for income taxes</link:label>
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    <link:label id="lab_us-gaap_AssetsNoncurrentOtherThanNoncurrentInvestmentsAndPropertyPlantAndEquipment_119dc36d-81ec-4e83-9355-682d58d340f8_totalLabel_en-US" xlink:label="lab_us-gaap_AssetsNoncurrentOtherThanNoncurrentInvestmentsAndPropertyPlantAndEquipment" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Total noncurrent assets</link:label>
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    <link:label id="lab_sm_A65SeniorUnsecuredNotesDue2028Member_04ffd487-0385-40b9-8d91-24d8ef3d4809_verboseLabel_en-US" xlink:label="lab_sm_A65SeniorUnsecuredNotesDue2028Member" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">6.5% Senior Unsecured Notes Due 2028</link:label>
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    <link:label id="lab_sm_OilBasisSwapContractFourthQuarterYear1Member_e9b46cd9-1595-4f9e-bf24-aad359422926_terseLabel_en-US" xlink:label="lab_sm_OilBasisSwapContractFourthQuarterYear1Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Oil Basis Swap Contract Fourth Quarter, Year 1</link:label>
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    <link:label id="lab_us-gaap_AwardTypeAxis_f06173f3-27c2-413b-b28e-024a87e8be13_terseLabel_en-US" xlink:label="lab_us-gaap_AwardTypeAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Award Type [Axis]</link:label>
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    <link:label id="lab_us-gaap_DerivativeAssetsNoncurrent_f730b8a7-b03d-4e0e-a51f-6a231b3603c1_verboseLabel_en-US" xlink:label="lab_us-gaap_DerivativeAssetsNoncurrent" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative assets, noncurrent</link:label>
    <link:label id="lab_us-gaap_DerivativeAssetsNoncurrent_label_en-US" xlink:label="lab_us-gaap_DerivativeAssetsNoncurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative Asset, Noncurrent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetsNoncurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeAssetsNoncurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeAssetsNoncurrent" xlink:to="lab_us-gaap_DerivativeAssetsNoncurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_FairValueMeasurementFrequencyDomain_4811624f-7521-4f15-a415-3b1e9b780344_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueMeasurementFrequencyDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Measurement Frequency [Domain]</link:label>
    <link:label id="lab_us-gaap_FairValueMeasurementFrequencyDomain_label_en-US" xlink:label="lab_us-gaap_FairValueMeasurementFrequencyDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Measurement Frequency [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
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    <link:label id="lab_us-gaap_DebtInstrumentFaceAmount_7a77dcaf-2a3e-4b11-84e9-7e0d4bc650d7_verboseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentFaceAmount" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Senior Notes, Principal amount</link:label>
    <link:label id="lab_us-gaap_DebtInstrumentFaceAmount_label_en-US" xlink:label="lab_us-gaap_DebtInstrumentFaceAmount" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Debt Instrument, Face Amount</link:label>
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    <link:label id="lab_us-gaap_InterestExpense_62f8612b-d17f-426d-a774-1f113604c7a8_negatedLabel_en-US" xlink:label="lab_us-gaap_InterestExpense" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Interest expense</link:label>
    <link:label id="lab_us-gaap_InterestExpense_label_en-US" xlink:label="lab_us-gaap_InterestExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Interest Expense</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InterestExpense" xlink:to="lab_us-gaap_InterestExpense" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AssetsNoncurrentAbstract_18ac9588-36ec-4fd2-aee8-4d2e56b20afc_terseLabel_en-US" xlink:label="lab_us-gaap_AssetsNoncurrentAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Noncurrent assets:</link:label>
    <link:label id="lab_us-gaap_AssetsNoncurrentAbstract_label_en-US" xlink:label="lab_us-gaap_AssetsNoncurrentAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Assets, Noncurrent [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsNoncurrentAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AssetsNoncurrentAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AssetsNoncurrentAbstract" xlink:to="lab_us-gaap_AssetsNoncurrentAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_sm_OilandCondensateRevenueMember_64dd31b5-57ea-4c51-bbcd-dcd6c35967c8_terseLabel_en-US" xlink:label="lab_sm_OilandCondensateRevenueMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">NGL production revenue</link:label>
    <link:label id="lab_sm_OilandCondensateRevenueMember_label_en-US" xlink:label="lab_sm_OilandCondensateRevenueMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Oil and Condensate Revenue [Member]</link:label>
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    <link:label id="lab_sm_WAHAMember_d1160e52-3ff6-4f29-8b60-876ef16c62c6_terseLabel_en-US" xlink:label="lab_sm_WAHAMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">WAHA [Member]</link:label>
    <link:label id="lab_sm_WAHAMember_label_en-US" xlink:label="lab_sm_WAHAMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">WAHA [Member]</link:label>
    <link:label id="lab_sm_WAHAMember_documentation_en-US" xlink:label="lab_sm_WAHAMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">WAHA [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_WAHAMember" xlink:href="sm-20210930.xsd#sm_WAHAMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_sm_WAHAMember" xlink:to="lab_sm_WAHAMember" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_CityAreaCode_d62c3a83-c4e2-42a6-9a42-030c66d10fe0_terseLabel_en-US" xlink:label="lab_dei_CityAreaCode" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">City Area Code</link:label>
    <link:label id="lab_dei_CityAreaCode_label_en-US" xlink:label="lab_dei_CityAreaCode" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">City Area Code</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode" xlink:href="https://xbrl.sec.gov/dei/2021/dei-2021.xsd#dei_CityAreaCode"/>
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    <link:label id="lab_us-gaap_RetainedEarningsAccumulatedDeficit_193580bc-f976-44e4-86f6-087b87120552_terseLabel_en-US" xlink:label="lab_us-gaap_RetainedEarningsAccumulatedDeficit" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Retained earnings (deficit)</link:label>
    <link:label id="lab_us-gaap_RetainedEarningsAccumulatedDeficit_label_en-US" xlink:label="lab_us-gaap_RetainedEarningsAccumulatedDeficit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Retained Earnings (Accumulated Deficit)</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RetainedEarningsAccumulatedDeficit" xlink:to="lab_us-gaap_RetainedEarningsAccumulatedDeficit" xlink:type="arc" order="1"/>
    <link:label id="lab_sm_NGLCollarContractYear2Member_60b87b57-bb10-4e82-b1e4-5c9cd993e340_terseLabel_en-US" xlink:label="lab_sm_NGLCollarContractYear2Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">NGL Collar Contract, Year 2</link:label>
    <link:label id="lab_sm_NGLCollarContractYear2Member_label_en-US" xlink:label="lab_sm_NGLCollarContractYear2Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">NGL Collar Contract, Year 2 [Member]</link:label>
    <link:label id="lab_sm_NGLCollarContractYear2Member_documentation_en-US" xlink:label="lab_sm_NGLCollarContractYear2Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">NGL Collar Contract, Year 2</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_NGLCollarContractYear2Member" xlink:href="sm-20210930.xsd#sm_NGLCollarContractYear2Member"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_sm_NGLCollarContractYear2Member" xlink:to="lab_sm_NGLCollarContractYear2Member" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_DerivativesFairValueLineItems_af6e4423-4516-4c51-8074-54cb18161514_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativesFairValueLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Fair value of derivative assets and liabilities</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativesFairValueLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativesFairValueLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativesFairValueLineItems" xlink:to="lab_us-gaap_DerivativesFairValueLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_RestrictedStockUnitsRSUMember_628feb5a-082e-4e7b-8c92-a29334e2c087_terseLabel_en-US" xlink:label="lab_us-gaap_RestrictedStockUnitsRSUMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Restricted Stock Units (RSUs)</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_RestrictedStockUnitsRSUMember" xlink:to="lab_us-gaap_RestrictedStockUnitsRSUMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_StatementOfStockholdersEquityAbstract_1345b017-b034-4a63-801f-57a36c71f89c_terseLabel_en-US" xlink:label="lab_us-gaap_StatementOfStockholdersEquityAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Statement of Stockholders' Equity [Abstract]</link:label>
    <link:label id="lab_us-gaap_StatementOfStockholdersEquityAbstract_label_en-US" xlink:label="lab_us-gaap_StatementOfStockholdersEquityAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Statement of Stockholders' Equity [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfStockholdersEquityAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementOfStockholdersEquityAbstract"/>
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    <link:label id="lab_sm_WarrantsPercentOfOutstandingStock_b035be64-7224-44ba-91f5-a0a72cf6e60a_terseLabel_en-US" xlink:label="lab_sm_WarrantsPercentOfOutstandingStock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Warrants Percent of Outstanding Stock</link:label>
    <link:label id="lab_sm_WarrantsPercentOfOutstandingStock_label_en-US" xlink:label="lab_sm_WarrantsPercentOfOutstandingStock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Warrants Percent of Outstanding Stock</link:label>
    <link:label id="lab_sm_WarrantsPercentOfOutstandingStock_documentation_en-US" xlink:label="lab_sm_WarrantsPercentOfOutstandingStock" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Warrants Percent of Outstanding Stock</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_WarrantsPercentOfOutstandingStock" xlink:href="sm-20210930.xsd#sm_WarrantsPercentOfOutstandingStock"/>
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    <link:label id="lab_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_3f6aa5f0-9c3d-40f9-b90a-b0537ca0ee27_terseLabel_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Issuance of common stock under Employee Stock Purchase Plan (Shares)</link:label>
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    <link:label id="lab_us-gaap_DerivativeCapPrice_81e0477a-0a9e-45f5-bd4b-7caf47dfbfd5_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeCapPrice" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative, Weighted-Average Ceiling Price</link:label>
    <link:label id="lab_us-gaap_DerivativeCapPrice_label_en-US" xlink:label="lab_us-gaap_DerivativeCapPrice" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative, Cap Price</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeCapPrice" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeCapPrice"/>
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    <link:label id="lab_us-gaap_IncomeStatementAbstract_b099df06-e2b6-4383-ac37-aba64994cd2a_terseLabel_en-US" xlink:label="lab_us-gaap_IncomeStatementAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Income Statement [Abstract]</link:label>
    <link:label id="lab_us-gaap_IncomeStatementAbstract_label_en-US" xlink:label="lab_us-gaap_IncomeStatementAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Income Statement [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeStatementAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_IncomeStatementAbstract" xlink:to="lab_us-gaap_IncomeStatementAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_AmendmentFlag_543b32e7-801a-426f-b706-74d5d6f9b199_terseLabel_en-US" xlink:label="lab_dei_AmendmentFlag" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Amendment Flag</link:label>
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    <link:label id="lab_us-gaap_ClassOfWarrantOrRighstDateFromWhichWarrantsOrRightsExercisable_label_en-US" xlink:label="lab_us-gaap_ClassOfWarrantOrRighstDateFromWhichWarrantsOrRightsExercisable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Class of Warrant or Right, Date from which Warrants or Rights Exercisable</link:label>
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    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentTypeDomain_a480bdbf-3829-4c4f-a5bf-0ef6219f9dcc_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Long-Lived Tangible Asset [Domain]</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
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    <link:label id="lab_dei_EntityIncorporationStateCountryCode_226943ad-227e-4982-9481-495471d0a331_terseLabel_en-US" xlink:label="lab_dei_EntityIncorporationStateCountryCode" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Entity Incorporation, State or Country Code</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossLineItems"/>
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    <link:label id="lab_dei_EntitySmallBusiness_a6f9fec5-36a9-423f-858e-567bf9ce4407_terseLabel_en-US" xlink:label="lab_dei_EntitySmallBusiness" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Entity Small Business</link:label>
    <link:label id="lab_dei_EntitySmallBusiness_label_en-US" xlink:label="lab_dei_EntitySmallBusiness" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Entity Small Business</link:label>
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    <link:label id="lab_us-gaap_SalesRevenueNetMember_de18d062-09fa-471e-8fdf-5b98981af9fb_terseLabel_en-US" xlink:label="lab_us-gaap_SalesRevenueNetMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Revenue Benchmark</link:label>
    <link:label id="lab_us-gaap_SalesRevenueNetMember_label_en-US" xlink:label="lab_us-gaap_SalesRevenueNetMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Revenue Benchmark [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SalesRevenueNetMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SalesRevenueNetMember"/>
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    <link:label id="lab_us-gaap_EquityComponentDomain_d5d81479-ff3e-48db-9393-e05dd5eaf3ff_terseLabel_en-US" xlink:label="lab_us-gaap_EquityComponentDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Equity Component [Domain]</link:label>
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    <link:label id="lab_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_27d7eb80-7be8-4b7b-9bf5-8d70d0ce84a6_terseLabel_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Stock-based compensation expense (shares)</link:label>
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    <link:label id="lab_sm_WellsInProgress_c0ffec0d-81fe-4630-91f9-63b88ca1718d_terseLabel_en-US" xlink:label="lab_sm_WellsInProgress" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Wells in progress</link:label>
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    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod_f16a2197-9714-488a-94c6-9651af7751e0_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Shares Issued in Period</link:label>
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    <link:label id="lab_us-gaap_ExtinguishmentOfDebtTypeDomain_c9a47a6c-4129-46cb-85c0-db996e14e8af_terseLabel_en-US" xlink:label="lab_us-gaap_ExtinguishmentOfDebtTypeDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Extinguishment of Debt, Type [Domain]</link:label>
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    <link:label id="lab_us-gaap_DeferredFinanceCostsGross_label_en-US" xlink:label="lab_us-gaap_DeferredFinanceCostsGross" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Debt Issuance Costs, Gross</link:label>
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    <link:label id="lab_us-gaap_LongTermLineOfCredit_label_en-US" xlink:label="lab_us-gaap_LongTermLineOfCredit" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Long-term Line of Credit, Noncurrent</link:label>
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    <link:label id="lab_us-gaap_AccruedIncomeReceivableMember_da742b91-50d1-456f-94a2-10a5f2001f6c_terseLabel_en-US" xlink:label="lab_us-gaap_AccruedIncomeReceivableMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Accrued Income Receivable</link:label>
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    <link:label id="lab_dei_EntityAddressStateOrProvince_9169c5a3-892f-43eb-b1bc-cf745fad5c0d_terseLabel_en-US" xlink:label="lab_dei_EntityAddressStateOrProvince" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Entity Address, State or Province</link:label>
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    <link:label id="lab_us-gaap_FairValueInputsLevel2Member_064f4e26-f98a-4f11-9488-9c7412094de9_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueInputsLevel2Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Fair Value, Inputs, Level 2</link:label>
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    <link:label id="lab_sm_GasCollarContractYear3Member_9f67e145-2c10-4345-b7ba-7f3f0ba73f80_terseLabel_en-US" xlink:label="lab_sm_GasCollarContractYear3Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Gas Collar Contract, Year 3</link:label>
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    <link:label id="lab_sm_ImpairmentsOfOilAndGasPropertiesTableTextBlock_dea0dad5-8afc-423e-8538-42b78b2481a1_terseLabel_en-US" xlink:label="lab_sm_ImpairmentsOfOilAndGasPropertiesTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Impairments of oil and gas properties</link:label>
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    <link:label id="lab_sm_NumberofSharesRepresentedbyEachRSU_1a04bec7-6ea9-4997-b779-dfbc671fc055_terseLabel_en-US" xlink:label="lab_sm_NumberofSharesRepresentedbyEachRSU" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Number of shares represented by each RSU</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_UnsecuredLongTermDebt" xlink:to="lab_us-gaap_UnsecuredLongTermDebt" xlink:type="arc" order="1"/>
    <link:label id="lab_sm_GasContractsMember_931f94b9-83b8-4abb-b9d9-c781d4ce15e4_terseLabel_en-US" xlink:label="lab_sm_GasContractsMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Gas Contracts [Member]</link:label>
    <link:label id="lab_sm_GasContractsMember_label_en-US" xlink:label="lab_sm_GasContractsMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Gas Contracts [Member]</link:label>
    <link:label id="lab_sm_GasContractsMember_documentation_en-US" xlink:label="lab_sm_GasContractsMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Gas Contracts [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_GasContractsMember" xlink:href="sm-20210930.xsd#sm_GasContractsMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_sm_GasContractsMember" xlink:to="lab_sm_GasContractsMember" xlink:type="arc" order="1"/>
    <link:label id="lab_sm_NGLCollarContractFourthQuarterYear1Member_80152332-accf-4856-84b4-b2a6f7de8426_terseLabel_en-US" xlink:label="lab_sm_NGLCollarContractFourthQuarterYear1Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">NGL Collar Contract, Fourth Quarter, Year 1</link:label>
    <link:label id="lab_sm_NGLCollarContractFourthQuarterYear1Member_label_en-US" xlink:label="lab_sm_NGLCollarContractFourthQuarterYear1Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">NGL Collar Contract, Fourth Quarter, Year 1 [Member]</link:label>
    <link:label id="lab_sm_NGLCollarContractFourthQuarterYear1Member_documentation_en-US" xlink:label="lab_sm_NGLCollarContractFourthQuarterYear1Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">NGL Collar Contract, Fourth Quarter, Year 1</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_NGLCollarContractFourthQuarterYear1Member" xlink:href="sm-20210930.xsd#sm_NGLCollarContractFourthQuarterYear1Member"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_sm_NGLCollarContractFourthQuarterYear1Member" xlink:to="lab_sm_NGLCollarContractFourthQuarterYear1Member" xlink:type="arc" order="1"/>
    <link:label id="lab_sm_GasCollarContractFirstQuarterYear3Member_302c2e1c-c74a-47bc-bcd6-2344217ccdbc_terseLabel_en-US" xlink:label="lab_sm_GasCollarContractFirstQuarterYear3Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Gas Collar Contract, First Quarter, Year 3</link:label>
    <link:label id="lab_sm_GasCollarContractFirstQuarterYear3Member_label_en-US" xlink:label="lab_sm_GasCollarContractFirstQuarterYear3Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Gas Collar Contract, First Quarter, Year 3 [Member]</link:label>
    <link:label id="lab_sm_GasCollarContractFirstQuarterYear3Member_documentation_en-US" xlink:label="lab_sm_GasCollarContractFirstQuarterYear3Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Gas Collar Contract, First Quarter, Year 3</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_GasCollarContractFirstQuarterYear3Member" xlink:href="sm-20210930.xsd#sm_GasCollarContractFirstQuarterYear3Member"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_sm_GasCollarContractFirstQuarterYear3Member" xlink:to="lab_sm_GasCollarContractFirstQuarterYear3Member" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_SeniorLongTermNotes_68df9681-04bd-4d85-b421-613a489577a7_terseLabel_en-US" xlink:label="lab_us-gaap_SeniorLongTermNotes" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Senior Notes, net</link:label>
    <link:label id="lab_us-gaap_SeniorLongTermNotes_label_en-US" xlink:label="lab_us-gaap_SeniorLongTermNotes" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Senior Notes, Noncurrent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorLongTermNotes" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SeniorLongTermNotes"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_SeniorLongTermNotes" xlink:to="lab_us-gaap_SeniorLongTermNotes" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock_12ab13ce-2dc3-401c-b4e1-4f88779c3c2e_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Schedule of calculations of basic and diluted net loss per common share</link:label>
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    <link:label id="lab_dei_EntityShellCompany_0b3fded5-7874-40ee-b84a-2055fd406675_terseLabel_en-US" xlink:label="lab_dei_EntityShellCompany" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Entity Shell Company</link:label>
    <link:label id="lab_dei_EntityShellCompany_label_en-US" xlink:label="lab_dei_EntityShellCompany" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Entity Shell Company</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityShellCompany" xlink:href="https://xbrl.sec.gov/dei/2021/dei-2021.xsd#dei_EntityShellCompany"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityShellCompany" xlink:to="lab_dei_EntityShellCompany" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_LocalPhoneNumber_8cc2b7fe-06f6-4640-b23d-10ee905f0d90_terseLabel_en-US" xlink:label="lab_dei_LocalPhoneNumber" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Local Phone Number</link:label>
    <link:label id="lab_dei_LocalPhoneNumber_label_en-US" xlink:label="lab_dei_LocalPhoneNumber" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Local Phone Number</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber" xlink:href="https://xbrl.sec.gov/dei/2021/dei-2021.xsd#dei_LocalPhoneNumber"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_LocalPhoneNumber" xlink:to="lab_dei_LocalPhoneNumber" xlink:type="arc" order="1"/>
    <link:label id="lab_sm_GasSwapsContractYear3Member_1bf4559d-3da9-4c2a-9d02-0e07240fd74c_terseLabel_en-US" xlink:label="lab_sm_GasSwapsContractYear3Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Gas Swaps Contract, Year 3</link:label>
    <link:label id="lab_sm_GasSwapsContractYear3Member_label_en-US" xlink:label="lab_sm_GasSwapsContractYear3Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Gas Swaps Contract, Year 3 [Member]</link:label>
    <link:label id="lab_sm_GasSwapsContractYear3Member_documentation_en-US" xlink:label="lab_sm_GasSwapsContractYear3Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Gas Swaps Contract, Year 3 [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_GasSwapsContractYear3Member" xlink:href="sm-20210930.xsd#sm_GasSwapsContractYear3Member"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_sm_GasSwapsContractYear3Member" xlink:to="lab_sm_GasSwapsContractYear3Member" xlink:type="arc" order="1"/>
    <link:label id="lab_sm_A150SeniorSecuredConvertibleNotesDue2021Member_291b4c2d-988f-42b9-bc98-fe75f6cd4dbd_terseLabel_en-US" xlink:label="lab_sm_A150SeniorSecuredConvertibleNotesDue2021Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">1.50% Senior Secured Convertible Notes Due 2021</link:label>
    <link:label id="lab_sm_A150SeniorSecuredConvertibleNotesDue2021Member_label_en-US" xlink:label="lab_sm_A150SeniorSecuredConvertibleNotesDue2021Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">1.50% Senior Secured Convertible Notes Due 2021 [Member]</link:label>
    <link:label id="lab_sm_A150SeniorSecuredConvertibleNotesDue2021Member_documentation_en-US" xlink:label="lab_sm_A150SeniorSecuredConvertibleNotesDue2021Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">1.50% Senior Secured Convertible Notes Due 2021 [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_A150SeniorSecuredConvertibleNotesDue2021Member" xlink:href="sm-20210930.xsd#sm_A150SeniorSecuredConvertibleNotesDue2021Member"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_sm_A150SeniorSecuredConvertibleNotesDue2021Member" xlink:to="lab_sm_A150SeniorSecuredConvertibleNotesDue2021Member" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ProceedsFromIssuanceOfCommonStock_01e26eb5-13df-4775-8c24-5c6563f91044_terseLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Net proceeds from sale of common stock</link:label>
    <link:label id="lab_us-gaap_ProceedsFromIssuanceOfCommonStock_label_en-US" xlink:label="lab_us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Proceeds from Issuance of Common Stock</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:to="lab_us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_Assets_4a8411fd-991a-4be2-a7ca-43de898cddc4_totalLabel_en-US" xlink:label="lab_us-gaap_Assets" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Total assets</link:label>
    <link:label id="lab_us-gaap_Assets_label_en-US" xlink:label="lab_us-gaap_Assets" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Assets</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Assets"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_Assets" xlink:to="lab_us-gaap_Assets" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ExplorationExpense_eb073a93-6825-40cd-968b-41fbc3a7730a_terseLabel_en-US" xlink:label="lab_us-gaap_ExplorationExpense" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Exploration</link:label>
    <link:label id="lab_us-gaap_ExplorationExpense_label_en-US" xlink:label="lab_us-gaap_ExplorationExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Exploration Expense</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ExplorationExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ExplorationExpense"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ExplorationExpense" xlink:to="lab_us-gaap_ExplorationExpense" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PlanNameDomain_c212d9d7-340f-4a32-bca9-2a3eafd5d4ae_terseLabel_en-US" xlink:label="lab_us-gaap_PlanNameDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Plan Name</link:label>
    <link:label id="lab_us-gaap_PlanNameDomain_label_en-US" xlink:label="lab_us-gaap_PlanNameDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Plan Name [Domain]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PlanNameDomain"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PlanNameDomain" xlink:to="lab_us-gaap_PlanNameDomain" xlink:type="arc" order="1"/>
    <link:label id="lab_srt_DirectorMember_0322b0d4-ffe1-4fdf-8302-4c8aceae9bb1_terseLabel_en-US" xlink:label="lab_srt_DirectorMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Director</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_srt_DirectorMember" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_DirectorMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_DirectorMember" xlink:to="lab_srt_DirectorMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CommonStockSharesAuthorized_4257e6c3-b597-422d-9f86-57ed100aead1_terseLabel_en-US" xlink:label="lab_us-gaap_CommonStockSharesAuthorized" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Common Stock, Shares Authorized</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommonStockSharesAuthorized" xlink:to="lab_us-gaap_CommonStockSharesAuthorized" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_InterestPaidNet_adbc6f07-a764-4b6d-9595-8c7573b15f7c_negatedLabel_en-US" xlink:label="lab_us-gaap_InterestPaidNet" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Cash paid for interest, net of capitalized interest</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_InterestPaidNet" xlink:to="lab_us-gaap_InterestPaidNet" xlink:type="arc" order="1"/>
    <link:label id="lab_srt_SegmentGeographicalDomain_1a2f188e-1416-4727-825f-be9ce2c81fe0_terseLabel_en-US" xlink:label="lab_srt_SegmentGeographicalDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Geographical [Domain]</link:label>
    <link:label id="lab_srt_SegmentGeographicalDomain_label_en-US" xlink:label="lab_srt_SegmentGeographicalDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Geographical [Domain]</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_srt_SegmentGeographicalDomain" xlink:to="lab_srt_SegmentGeographicalDomain" xlink:type="arc" order="1"/>
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    <link:label id="lab_srt_ProductsAndServicesDomain_7c1a89dd-0bfb-40d1-bbd8-c0a8e0e0cb22_terseLabel_en-US" xlink:label="lab_srt_ProductsAndServicesDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Product and Service [Domain]</link:label>
    <link:label id="lab_srt_ProductsAndServicesDomain_label_en-US" xlink:label="lab_srt_ProductsAndServicesDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Product and Service [Domain]</link:label>
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    <link:label id="lab_us-gaap_ProvedOilAndGasPropertySuccessfulEffortMethod_0aff68b0-898b-4a76-9c7f-cc6d76f71d66_verboseLabel_en-US" xlink:label="lab_us-gaap_ProvedOilAndGasPropertySuccessfulEffortMethod" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Proved oil and gas properties</link:label>
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    <link:label id="lab_us-gaap_DebtInstrumentInterestRateStatedPercentage_eacab29c-410d-4441-9ff3-bfafeee61095_verboseLabel_en-US" xlink:label="lab_us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Senior Notes, interest rate, stated percentage</link:label>
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    <link:label id="lab_us-gaap_DerivativeContractTypeDomain_c13ca6be-949e-45a9-9922-277062410c08_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeContractTypeDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative Name [Domain]</link:label>
    <link:label id="lab_us-gaap_DerivativeContractTypeDomain_label_en-US" xlink:label="lab_us-gaap_DerivativeContractTypeDomain" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative Contract [Domain]</link:label>
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    <link:label id="lab_us-gaap_LiabilitiesNoncurrent_3b00f227-8c62-405a-9616-223f1980aa72_totalLabel_en-US" xlink:label="lab_us-gaap_LiabilitiesNoncurrent" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Total noncurrent liabilities</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LiabilitiesNoncurrent" xlink:to="lab_us-gaap_LiabilitiesNoncurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_sm_NYMEXHHMember_a3363f81-b3f4-4c4e-b9e9-3a938c806ce8_terseLabel_en-US" xlink:label="lab_sm_NYMEXHHMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">NYMEX HH</link:label>
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    <link:label id="lab_sm_NYMEXHHMember_documentation_en-US" xlink:label="lab_sm_NYMEXHHMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">NYMEX HH</link:label>
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    <link:label id="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_2bf81a90-228d-48da-9d06-7f61e7631ca7_terseLabel_en-US" xlink:label="lab_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Share-based Compensation Arrangement by Share-based Payment Award</link:label>
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    <link:label id="lab_us-gaap_ScheduleOfLineOfCreditFacilitiesTextBlock_406d2454-7a5c-4ef6-857b-ae4caa426b36_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfLineOfCreditFacilitiesTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Schedule of Line of Credit Facilities [Table Text Block]</link:label>
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    <link:label id="lab_us-gaap_RevolvingCreditFacilityMember_980454da-ce06-443c-8227-f047eb6edc66_terseLabel_en-US" xlink:label="lab_us-gaap_RevolvingCreditFacilityMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Revolving Credit Facility [Member]</link:label>
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    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentFairValueDisclosure_c38b3925-94cb-4915-80c1-b3103ddfaf36_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentFairValueDisclosure" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Property, Plant, and Equipment, Fair Value Disclosure</link:label>
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    <link:label id="lab_us-gaap_FairValueByMeasurementFrequencyAxis_ff2b44fa-8c86-4b30-8d39-ac82554d5bad_terseLabel_en-US" xlink:label="lab_us-gaap_FairValueByMeasurementFrequencyAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Measurement Frequency [Axis]</link:label>
    <link:label id="lab_us-gaap_FairValueByMeasurementFrequencyAxis_label_en-US" xlink:label="lab_us-gaap_FairValueByMeasurementFrequencyAxis" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Measurement Frequency [Axis]</link:label>
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    <link:label id="lab_us-gaap_NetCashProvidedByUsedInOperatingActivities_486d7d9c-7c7d-44f5-b01e-da9d3cec9500_totalLabel_en-US" xlink:label="lab_us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Net cash provided by operating activities</link:label>
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    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentOtherNet_205d1f5f-e791-41c4-accd-fa69422c6fbc_terseLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentOtherNet" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other property and equipment, net of accumulated depreciation of $65,462 and $63,662, respectively</link:label>
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    <link:label id="lab_us-gaap_ConcentrationRiskByTypeAxis_f6cfcb42-ed47-4493-b473-97a5f834773b_terseLabel_en-US" xlink:label="lab_us-gaap_ConcentrationRiskByTypeAxis" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Concentration Type [Axis]</link:label>
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    <link:label id="lab_us-gaap_AccumulatedOtherComprehensiveIncomeMember_e5ba3886-8750-4aef-86b7-0fe07911ef01_terseLabel_en-US" xlink:label="lab_us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Accumulated Other Comprehensive Loss</link:label>
    <link:label id="lab_us-gaap_AccumulatedOtherComprehensiveIncomeMember_label_en-US" xlink:label="lab_us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">AOCI Attributable to Parent [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
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    <link:label id="lab_sm_OilRevenueMember_f7a88340-02a8-4c0f-844c-ef71bdbb79ea_terseLabel_en-US" xlink:label="lab_sm_OilRevenueMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Oil production revenue</link:label>
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    <link:label id="lab_us-gaap_CommonStockSharesOutstanding_b6d080d5-11de-448f-81c1-45072795d002_terseLabel_en-US" xlink:label="lab_us-gaap_CommonStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Common Stock, Shares, Outstanding</link:label>
    <link:label id="lab_us-gaap_CommonStockSharesOutstanding_c8c59f03-ae3a-449d-854d-f927844b6058_periodStartLabel_en-US" xlink:label="lab_us-gaap_CommonStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Balances, Common Stock, Shares, Outstanding, Beginning</link:label>
    <link:label id="lab_us-gaap_CommonStockSharesOutstanding_16999373-6acd-41a4-b2a8-1c19a1c7ac30_periodEndLabel_en-US" xlink:label="lab_us-gaap_CommonStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Balances, Common Stock, Shares, Outstanding, Ending</link:label>
    <link:label id="lab_us-gaap_CommonStockSharesOutstanding_label_en-US" xlink:label="lab_us-gaap_CommonStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Common Stock, Shares, Outstanding</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockSharesOutstanding"/>
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    <link:label id="lab_sm_IfHscMember_16ba083d-7102-4dad-9dbe-042a63e69eb9_terseLabel_en-US" xlink:label="lab_sm_IfHscMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">IF HSC [Member]</link:label>
    <link:label id="lab_sm_IfHscMember_label_en-US" xlink:label="lab_sm_IfHscMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">IF HSC [Member]</link:label>
    <link:label id="lab_sm_IfHscMember_documentation_en-US" xlink:label="lab_sm_IfHscMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">IF HSC [Member]</link:label>
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    <link:label id="lab_us-gaap_OtherOperatingIncomeExpenseNet_0c3379f7-6b41-412d-b040-e90d1efb2d69_negatedLabel_en-US" xlink:label="lab_us-gaap_OtherOperatingIncomeExpenseNet" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other operating expense, net</link:label>
    <link:label id="lab_us-gaap_OtherOperatingIncomeExpenseNet_label_en-US" xlink:label="lab_us-gaap_OtherOperatingIncomeExpenseNet" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other Operating Income (Expense), Net</link:label>
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    <link:label id="lab_us-gaap_DerivativeTable_d7831558-f63a-49a5-bed7-1938517f3a95_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative [Table]</link:label>
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    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeTable"/>
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    <link:label id="lab_sm_SeniorUnsecuredNotesMember_ceb2e202-a22d-4e12-9ff9-0262559b119d_terseLabel_en-US" xlink:label="lab_sm_SeniorUnsecuredNotesMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Senior Unsecured Notes [Member]</link:label>
    <link:label id="lab_sm_SeniorUnsecuredNotesMember_label_en-US" xlink:label="lab_sm_SeniorUnsecuredNotesMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Senior Unsecured Notes [Member]</link:label>
    <link:label id="lab_sm_SeniorUnsecuredNotesMember_documentation_en-US" xlink:label="lab_sm_SeniorUnsecuredNotesMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Senior Unsecured Notes</link:label>
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    <link:label id="lab_sm_NYMEXOilCalendarMonthAverageRollDifferentialContractYear2Member_7a0ec7bf-3e6e-4984-919b-db49e6b70ca4_terseLabel_en-US" xlink:label="lab_sm_NYMEXOilCalendarMonthAverageRollDifferentialContractYear2Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">NYMEX Oil Calendar Month Average Roll Differential Contract, Year 2</link:label>
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    <link:label id="lab_sm_GasBasisSwapContractYear2Member_5fabebdb-f269-4f78-852e-4da0025c2963_terseLabel_en-US" xlink:label="lab_sm_GasBasisSwapContractYear2Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Gas Basis Swap Contract, Year 2</link:label>
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    <link:label id="lab_sm_GasBasisSwapContractYear2Member_documentation_en-US" xlink:label="lab_sm_GasBasisSwapContractYear2Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Gas Basis Swap Contract, Year 2</link:label>
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    <link:label id="lab_us-gaap_ConcentrationRiskBenchmarkDomain_1ca5bc62-2f13-4454-ad28-d82df6860906_terseLabel_en-US" xlink:label="lab_us-gaap_ConcentrationRiskBenchmarkDomain" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Concentration Benchmark [Domain]</link:label>
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    <link:label id="lab_us-gaap_PropertyPlantAndEquipmentNet_15f10d2e-f51f-4988-9ed8-adb3b4bbbf92_totalLabel_en-US" xlink:label="lab_us-gaap_PropertyPlantAndEquipmentNet" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Total property and equipment, net</link:label>
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    <link:label id="lab_us-gaap_OtherLiabilitiesNoncurrent_075486d8-1788-43ad-a177-32dbf4d50686_terseLabel_en-US" xlink:label="lab_us-gaap_OtherLiabilitiesNoncurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other noncurrent liabilities</link:label>
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    <link:label id="lab_sm_FairValueAssumptionsMeasurementInput_documentation_en-US" xlink:label="lab_sm_FairValueAssumptionsMeasurementInput" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Assumption used in valuing an instrument.</link:label>
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    <link:label id="lab_us-gaap_EarningsPerShareAbstract_label_en-US" xlink:label="lab_us-gaap_EarningsPerShareAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Earnings Per Share [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EarningsPerShareAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EarningsPerShareAbstract" xlink:to="lab_us-gaap_EarningsPerShareAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_sm_Derivativesettlementgainorloss_87113f2f-125a-41f1-8304-1ba149434700_terseLabel_en-US" xlink:label="lab_sm_Derivativesettlementgainorloss" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative settlement (gain) loss</link:label>
    <link:label id="lab_sm_Derivativesettlementgainorloss_label_en-US" xlink:label="lab_sm_Derivativesettlementgainorloss" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative settlement gain or loss</link:label>
    <link:label id="lab_sm_Derivativesettlementgainorloss_documentation_en-US" xlink:label="lab_sm_Derivativesettlementgainorloss" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Realized gain or loss recognized in earnings from the settlement of derivative instruments not designated as hedges.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_Derivativesettlementgainorloss" xlink:href="sm-20210930.xsd#sm_Derivativesettlementgainorloss"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_sm_Derivativesettlementgainorloss" xlink:to="lab_sm_Derivativesettlementgainorloss" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_DocumentQuarterlyReport_aa32b655-3481-4dab-8170-d6ab0a2c02b5_terseLabel_en-US" xlink:label="lab_dei_DocumentQuarterlyReport" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Document Quarterly Report</link:label>
    <link:label id="lab_dei_DocumentQuarterlyReport_label_en-US" xlink:label="lab_dei_DocumentQuarterlyReport" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Document Quarterly Report</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentQuarterlyReport" xlink:href="https://xbrl.sec.gov/dei/2021/dei-2021.xsd#dei_DocumentQuarterlyReport"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_DocumentQuarterlyReport" xlink:to="lab_dei_DocumentQuarterlyReport" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_Revenues_5cda0ff6-d176-4079-98f7-992f45b5967d_totalLabel_en-US" xlink:label="lab_us-gaap_Revenues" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Total operating revenues and other income</link:label>
    <link:label id="lab_us-gaap_Revenues_label_en-US" xlink:label="lab_us-gaap_Revenues" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Revenues</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Revenues"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_Revenues" xlink:to="lab_us-gaap_Revenues" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_1f1d8f76-c9c1-4cc6-8c3d-5c983ea6450f_terseLabel_en-US" xlink:label="lab_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Exercise Price of Warrants</link:label>
    <link:label id="lab_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_label_en-US" xlink:label="lab_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Class of Warrant or Right, Exercise Price of Warrants or Rights</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xlink:to="lab_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_45599029-89a6-442c-a3eb-c4642f042f8d_terseLabel_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Revolving credit facility, current borrowing base</link:label>
    <link:label id="lab_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_label_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Line of Credit Facility, Current Borrowing Capacity</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity" xlink:to="lab_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity" xlink:type="arc" order="1"/>
    <link:label id="lab_sm_ImpairmentofProvedOilandGasProperties_72e20505-f5ec-42bf-b006-da341f591fe6_terseLabel_en-US" xlink:label="lab_sm_ImpairmentofProvedOilandGasProperties" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Impairment of Proved Oil and Gas Properties</link:label>
    <link:label id="lab_sm_ImpairmentofProvedOilandGasProperties_label_en-US" xlink:label="lab_sm_ImpairmentofProvedOilandGasProperties" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Impairment of Proved Oil and Gas Properties</link:label>
    <link:label id="lab_sm_ImpairmentofProvedOilandGasProperties_documentation_en-US" xlink:label="lab_sm_ImpairmentofProvedOilandGasProperties" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">The impairment expense recorded to reduce the value of proved oil and gas assets.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_ImpairmentofProvedOilandGasProperties" xlink:href="sm-20210930.xsd#sm_ImpairmentofProvedOilandGasProperties"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_sm_ImpairmentofProvedOilandGasProperties" xlink:to="lab_sm_ImpairmentofProvedOilandGasProperties" xlink:type="arc" order="1"/>
    <link:label id="lab_sm_LineofCreditFacilityAggregateLenderCommitments_53158e36-51d3-457d-becb-fd0317aa790d_totalLabel_en-US" xlink:label="lab_sm_LineofCreditFacilityAggregateLenderCommitments" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Revolving credit facility, aggregate lender commitments</link:label>
    <link:label id="lab_sm_LineofCreditFacilityAggregateLenderCommitments_label_en-US" xlink:label="lab_sm_LineofCreditFacilityAggregateLenderCommitments" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Line of Credit Facility, Aggregate Lender Commitments</link:label>
    <link:label id="lab_sm_LineofCreditFacilityAggregateLenderCommitments_documentation_en-US" xlink:label="lab_sm_LineofCreditFacilityAggregateLenderCommitments" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Line of Credit Facility, Aggregate Lender Commitments</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_LineofCreditFacilityAggregateLenderCommitments" xlink:href="sm-20210930.xsd#sm_LineofCreditFacilityAggregateLenderCommitments"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_sm_LineofCreditFacilityAggregateLenderCommitments" xlink:to="lab_sm_LineofCreditFacilityAggregateLenderCommitments" xlink:type="arc" order="1"/>
    <link:label id="lab_sm_IndexPercentOfNaturalGasFixedSwaps_a0e8ee62-9e6f-42fa-ba6d-893db0628a68_terseLabel_en-US" xlink:label="lab_sm_IndexPercentOfNaturalGasFixedSwaps" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Index percent of natural gas fixed swaps</link:label>
    <link:label id="lab_sm_IndexPercentOfNaturalGasFixedSwaps_label_en-US" xlink:label="lab_sm_IndexPercentOfNaturalGasFixedSwaps" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Index percent of natural gas fixed swaps</link:label>
    <link:label id="lab_sm_IndexPercentOfNaturalGasFixedSwaps_documentation_en-US" xlink:label="lab_sm_IndexPercentOfNaturalGasFixedSwaps" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Index percent of natural gas fixed swaps</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_IndexPercentOfNaturalGasFixedSwaps" xlink:href="sm-20210930.xsd#sm_IndexPercentOfNaturalGasFixedSwaps"/>
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    <link:label id="lab_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAbstract_c1da43f1-6ac4-435a-91ad-e5fb748248ce_terseLabel_en-US" xlink:label="lab_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Derivative Instruments Not Designated as Hedging Instruments [Abstract]</link:label>
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    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAbstract" xlink:to="lab_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LineOfCreditFacilityTable_8f5e8ec2-3d57-4d59-ad14-9d1c78c8d6e4_terseLabel_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Line of Credit Facility [Table]</link:label>
    <link:label id="lab_us-gaap_LineOfCreditFacilityTable_label_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Line of Credit Facility [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityTable" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LineOfCreditFacilityTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LineOfCreditFacilityTable" xlink:to="lab_us-gaap_LineOfCreditFacilityTable" xlink:type="arc" order="1"/>
    <link:label id="lab_sm_GasBasisSwapContractFourthQuarterYear1Member_372730e5-9762-4cd5-adad-0df542387f39_terseLabel_en-US" xlink:label="lab_sm_GasBasisSwapContractFourthQuarterYear1Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Gas Basis Swap Contract Fourth Quarter, Year 1</link:label>
    <link:label id="lab_sm_GasBasisSwapContractFourthQuarterYear1Member_label_en-US" xlink:label="lab_sm_GasBasisSwapContractFourthQuarterYear1Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Gas Basis Swap Contract Fourth Quarter, Year 1 [Member]</link:label>
    <link:label id="lab_sm_GasBasisSwapContractFourthQuarterYear1Member_documentation_en-US" xlink:label="lab_sm_GasBasisSwapContractFourthQuarterYear1Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Gas Basis Swap Contract Fourth Quarter, Year 1</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_GasBasisSwapContractFourthQuarterYear1Member" xlink:href="sm-20210930.xsd#sm_GasBasisSwapContractFourthQuarterYear1Member"/>
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    <link:label id="lab_us-gaap_OtherCommitmentsLineItems_bd3f1cbf-7a3d-442b-bf1b-b1ba7175b3d7_terseLabel_en-US" xlink:label="lab_us-gaap_OtherCommitmentsLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Commitments and Contingencies [Line Items]</link:label>
    <link:label id="lab_us-gaap_OtherCommitmentsLineItems_label_en-US" xlink:label="lab_us-gaap_OtherCommitmentsLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other Commitments [Line Items]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentsLineItems" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherCommitmentsLineItems"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_OtherCommitmentsLineItems" xlink:to="lab_us-gaap_OtherCommitmentsLineItems" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_EntityCommonStockSharesOutstanding_497644cf-3e37-4816-8554-7e3822e310b8_terseLabel_en-US" xlink:label="lab_dei_EntityCommonStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Entity Common Stock, Shares Outstanding</link:label>
    <link:label id="lab_dei_EntityCommonStockSharesOutstanding_label_en-US" xlink:label="lab_dei_EntityCommonStockSharesOutstanding" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Entity Common Stock, Shares Outstanding</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCommonStockSharesOutstanding" xlink:href="https://xbrl.sec.gov/dei/2021/dei-2021.xsd#dei_EntityCommonStockSharesOutstanding"/>
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    <link:label id="lab_us-gaap_CostsAndExpensesAbstract_5282131e-fe0e-4e92-ae9b-d9e224eb943b_terseLabel_en-US" xlink:label="lab_us-gaap_CostsAndExpensesAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Operating expenses:</link:label>
    <link:label id="lab_us-gaap_CostsAndExpensesAbstract_label_en-US" xlink:label="lab_us-gaap_CostsAndExpensesAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Costs and Expenses [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostsAndExpensesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CostsAndExpensesAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CostsAndExpensesAbstract" xlink:to="lab_us-gaap_CostsAndExpensesAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PaymentsToExploreAndDevelopOilAndGasProperties_e167b50a-4fc4-4786-a292-f0e8a7f67009_negatedLabel_en-US" xlink:label="lab_us-gaap_PaymentsToExploreAndDevelopOilAndGasProperties" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Capital expenditures</link:label>
    <link:label id="lab_us-gaap_PaymentsToExploreAndDevelopOilAndGasProperties_label_en-US" xlink:label="lab_us-gaap_PaymentsToExploreAndDevelopOilAndGasProperties" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Payments to Explore and Develop Oil and Gas Properties</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToExploreAndDevelopOilAndGasProperties" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsToExploreAndDevelopOilAndGasProperties"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PaymentsToExploreAndDevelopOilAndGasProperties" xlink:to="lab_us-gaap_PaymentsToExploreAndDevelopOilAndGasProperties" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_StockIssuedDuringPeriodValueOther_16a0f0a5-5276-4d13-84b4-949fa3ad671b_terseLabel_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodValueOther" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Issuance of common stock through cashless exercise of warrants (Amount)</link:label>
    <link:label id="lab_us-gaap_StockIssuedDuringPeriodValueOther_label_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodValueOther" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Stock Issued During Period, Value, Other</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueOther" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueOther"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockIssuedDuringPeriodValueOther" xlink:to="lab_us-gaap_StockIssuedDuringPeriodValueOther" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AllocatedShareBasedCompensationExpense_9f1620e5-1569-4427-a161-5c7d46c5b0c8_terseLabel_en-US" xlink:label="lab_us-gaap_AllocatedShareBasedCompensationExpense" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Stock-based compensation expense</link:label>
    <link:label id="lab_us-gaap_AllocatedShareBasedCompensationExpense_label_en-US" xlink:label="lab_us-gaap_AllocatedShareBasedCompensationExpense" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Share-based Payment Arrangement, Expense</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AllocatedShareBasedCompensationExpense" xlink:to="lab_us-gaap_AllocatedShareBasedCompensationExpense" xlink:type="arc" order="1"/>
    <link:label id="lab_sm_StockIssuedDuringPeriodValueRestrictedStockUnitsAndPerformanceShareUnits_7177a12c-126e-4834-b3a7-910ba9c01883_terseLabel_en-US" xlink:label="lab_sm_StockIssuedDuringPeriodValueRestrictedStockUnitsAndPerformanceShareUnits" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Issuance of common stock upon vesting of RSUs and settlement of PSUs, net of shares used for tax withholdings (Amount)</link:label>
    <link:label id="lab_sm_StockIssuedDuringPeriodValueRestrictedStockUnitsAndPerformanceShareUnits_label_en-US" xlink:label="lab_sm_StockIssuedDuringPeriodValueRestrictedStockUnitsAndPerformanceShareUnits" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Stock Issued During Period, Value, Restricted Stock Units And Performance Share Units</link:label>
    <link:label id="lab_sm_StockIssuedDuringPeriodValueRestrictedStockUnitsAndPerformanceShareUnits_documentation_en-US" xlink:label="lab_sm_StockIssuedDuringPeriodValueRestrictedStockUnitsAndPerformanceShareUnits" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Aggregate change in value for shares issued during the period as a result of vesting of RSUs and settlement of PSUs, net of shares used for tax withholdings.</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_StockIssuedDuringPeriodValueRestrictedStockUnitsAndPerformanceShareUnits" xlink:href="sm-20210930.xsd#sm_StockIssuedDuringPeriodValueRestrictedStockUnitsAndPerformanceShareUnits"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_sm_StockIssuedDuringPeriodValueRestrictedStockUnitsAndPerformanceShareUnits" xlink:to="lab_sm_StockIssuedDuringPeriodValueRestrictedStockUnitsAndPerformanceShareUnits" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_DocumentFiscalPeriodFocus_b863a4ef-5d71-43cd-993d-e84f1e6985e3_terseLabel_en-US" xlink:label="lab_dei_DocumentFiscalPeriodFocus" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Document Fiscal Period Focus</link:label>
    <link:label id="lab_dei_DocumentFiscalPeriodFocus_label_en-US" xlink:label="lab_dei_DocumentFiscalPeriodFocus" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Document Fiscal Period Focus</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalPeriodFocus" xlink:href="https://xbrl.sec.gov/dei/2021/dei-2021.xsd#dei_DocumentFiscalPeriodFocus"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_DocumentFiscalPeriodFocus" xlink:to="lab_dei_DocumentFiscalPeriodFocus" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_LongTermPurchaseCommitmentTable_0c5b3e86-f032-4665-8c17-ac45d9fc4d59_terseLabel_en-US" xlink:label="lab_us-gaap_LongTermPurchaseCommitmentTable" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Long-term Purchase Commitment [Table]</link:label>
    <link:label id="lab_us-gaap_LongTermPurchaseCommitmentTable_label_en-US" xlink:label="lab_us-gaap_LongTermPurchaseCommitmentTable" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Long-term Purchase Commitment [Table]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermPurchaseCommitmentTable" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermPurchaseCommitmentTable"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_LongTermPurchaseCommitmentTable" xlink:to="lab_us-gaap_LongTermPurchaseCommitmentTable" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_EffectiveIncomeTaxRateContinuingOperations_fde8b615-2614-4a5b-8372-aaa85bec02a5_terseLabel_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Effective tax rate</link:label>
    <link:label id="lab_us-gaap_EffectiveIncomeTaxRateContinuingOperations_label_en-US" xlink:label="lab_us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Effective Income Tax Rate Reconciliation, Percent</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperations"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:to="lab_us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AccountsReceivableGrossCurrent_700cf2cd-1b98-44a1-85ae-e2d871e6d6a2_terseLabel_en-US" xlink:label="lab_us-gaap_AccountsReceivableGrossCurrent" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Accounts receivable from contracts with customers</link:label>
    <link:label id="lab_us-gaap_AccountsReceivableGrossCurrent_label_en-US" xlink:label="lab_us-gaap_AccountsReceivableGrossCurrent" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Accounts Receivable, before Allowance for Credit Loss, Current</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableGrossCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccountsReceivableGrossCurrent"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AccountsReceivableGrossCurrent" xlink:to="lab_us-gaap_AccountsReceivableGrossCurrent" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_PaymentsToAcquireOilAndGasPropertyAndEquipment_cfd04d67-4516-4572-b4b0-6814c366dc46_negatedTerseLabel_en-US" xlink:label="lab_us-gaap_PaymentsToAcquireOilAndGasPropertyAndEquipment" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Acquisition of proved and unproved oil and gas properties</link:label>
    <link:label id="lab_us-gaap_PaymentsToAcquireOilAndGasPropertyAndEquipment_label_en-US" xlink:label="lab_us-gaap_PaymentsToAcquireOilAndGasPropertyAndEquipment" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Payments to Acquire Oil and Gas Property and Equipment</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireOilAndGasPropertyAndEquipment" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsToAcquireOilAndGasPropertyAndEquipment"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_PaymentsToAcquireOilAndGasPropertyAndEquipment" xlink:to="lab_us-gaap_PaymentsToAcquireOilAndGasPropertyAndEquipment" xlink:type="arc" order="1"/>
    <link:label id="lab_sm_GasCollarContractYear2Member_89ad55d3-b3ca-4573-a8e6-6abcfd2a289b_terseLabel_en-US" xlink:label="lab_sm_GasCollarContractYear2Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Gas Collar Contract, Year 2</link:label>
    <link:label id="lab_sm_GasCollarContractYear2Member_label_en-US" xlink:label="lab_sm_GasCollarContractYear2Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Gas Collar Contract, Year 2 [Member]</link:label>
    <link:label id="lab_sm_GasCollarContractYear2Member_documentation_en-US" xlink:label="lab_sm_GasCollarContractYear2Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Gas Collar Contract, Year 2</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_GasCollarContractYear2Member" xlink:href="sm-20210930.xsd#sm_GasCollarContractYear2Member"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_sm_GasCollarContractYear2Member" xlink:to="lab_sm_GasCollarContractYear2Member" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_StockIssuedDuringPeriodSharesOther_0b38fa8e-8cc0-41ed-ae90-45692f41bfeb_terseLabel_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesOther" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Issuance of common stock through cashless exercise of warrants (Shares)</link:label>
    <link:label id="lab_us-gaap_StockIssuedDuringPeriodSharesOther_label_en-US" xlink:label="lab_us-gaap_StockIssuedDuringPeriodSharesOther" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Stock Issued During Period, Shares, Other</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesOther" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesOther"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StockIssuedDuringPeriodSharesOther" xlink:to="lab_us-gaap_StockIssuedDuringPeriodSharesOther" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_CommonStockParOrStatedValuePerShare_19569db4-ca57-4eeb-869d-8dd30c8e8722_terseLabel_en-US" xlink:label="lab_us-gaap_CommonStockParOrStatedValuePerShare" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Common Stock, Par Value Per Share</link:label>
    <link:label id="lab_us-gaap_CommonStockParOrStatedValuePerShare_label_en-US" xlink:label="lab_us-gaap_CommonStockParOrStatedValuePerShare" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Common Stock, Par or Stated Value Per Share</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_CommonStockParOrStatedValuePerShare" xlink:to="lab_us-gaap_CommonStockParOrStatedValuePerShare" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_MeasurementInputDiscountRateMember_b0ab4706-e922-4985-8628-af45dc17f5ad_terseLabel_en-US" xlink:label="lab_us-gaap_MeasurementInputDiscountRateMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Measurement Input, Discount Rate</link:label>
    <link:label id="lab_us-gaap_MeasurementInputDiscountRateMember_label_en-US" xlink:label="lab_us-gaap_MeasurementInputDiscountRateMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Measurement Input, Discount Rate [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputDiscountRateMember" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MeasurementInputDiscountRateMember"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_MeasurementInputDiscountRateMember" xlink:to="lab_us-gaap_MeasurementInputDiscountRateMember" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract_5d4952fc-dfc3-4f15-b88d-db50f2714854_terseLabel_en-US" xlink:label="lab_us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Statement of Comprehensive Income [Abstract]</link:label>
    <link:label id="lab_us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract_label_en-US" xlink:label="lab_us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Statement of Comprehensive Income [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:to="lab_us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_AssetsCurrentAbstract_24e48828-850e-416d-b62f-6b44259ce0b6_terseLabel_en-US" xlink:label="lab_us-gaap_AssetsCurrentAbstract" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Current assets:</link:label>
    <link:label id="lab_us-gaap_AssetsCurrentAbstract_label_en-US" xlink:label="lab_us-gaap_AssetsCurrentAbstract" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Assets, Current [Abstract]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrentAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AssetsCurrentAbstract"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_AssetsCurrentAbstract" xlink:to="lab_us-gaap_AssetsCurrentAbstract" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities_c65e86c8-07d0-4ed9-a594-911963302228_terseLabel_en-US" xlink:label="lab_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Other, net</link:label>
    <link:label id="lab_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities_label_en-US" xlink:label="lab_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Proceeds from (Payments for) Other Financing Activities</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromPaymentsForOtherFinancingActivities"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities" xlink:to="lab_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_EntityCentralIndexKey_9b37e2a1-b7bf-4ece-a52a-ea4e22b9ad1b_terseLabel_en-US" xlink:label="lab_dei_EntityCentralIndexKey" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Entity Central Index Key</link:label>
    <link:label id="lab_dei_EntityCentralIndexKey_label_en-US" xlink:label="lab_dei_EntityCentralIndexKey" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Entity Central Index Key</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey" xlink:href="https://xbrl.sec.gov/dei/2021/dei-2021.xsd#dei_EntityCentralIndexKey"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_EntityCentralIndexKey" xlink:to="lab_dei_EntityCentralIndexKey" xlink:type="arc" order="1"/>
    <link:label id="lab_dei_SecurityExchangeName_81f5f733-c472-491f-89ba-5b469144daf8_terseLabel_en-US" xlink:label="lab_dei_SecurityExchangeName" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Security Exchange Name</link:label>
    <link:label id="lab_dei_SecurityExchangeName_label_en-US" xlink:label="lab_dei_SecurityExchangeName" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Security Exchange Name</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName" xlink:href="https://xbrl.sec.gov/dei/2021/dei-2021.xsd#dei_SecurityExchangeName"/>
    <link:labelArc xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_dei_SecurityExchangeName" xlink:to="lab_dei_SecurityExchangeName" xlink:type="arc" order="1"/>
    <link:label id="lab_us-gaap_ScheduleOfNonvestedPerformanceBasedUnitsActivityTableTextBlock_be46bc0f-be6a-4946-bd0e-7fe1fe87c71c_terseLabel_en-US" xlink:label="lab_us-gaap_ScheduleOfNonvestedPerformanceBasedUnitsActivityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Schedule of non-vested PSUs</link:label>
    <link:label id="lab_us-gaap_ScheduleOfNonvestedPerformanceBasedUnitsActivityTableTextBlock_label_en-US" xlink:label="lab_us-gaap_ScheduleOfNonvestedPerformanceBasedUnitsActivityTableTextBlock" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Schedule of Nonvested Performance-based Units Activity [Table Text Block]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfNonvestedPerformanceBasedUnitsActivityTableTextBlock" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfNonvestedPerformanceBasedUnitsActivityTableTextBlock"/>
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    <link:label id="lab_us-gaap_LiabilitiesCurrent_a682a1d3-242c-42e4-8a58-f6c1c50a3ef3_totalLabel_en-US" xlink:label="lab_us-gaap_LiabilitiesCurrent" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Total current liabilities</link:label>
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    <link:label id="lab_sm_A6125SeniorUnsecuredNotesDue2022And50SeniorUnsecuredNotesDue2024Member_label_en-US" xlink:label="lab_sm_A6125SeniorUnsecuredNotesDue2022And50SeniorUnsecuredNotesDue2024Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">6.125% Senior Unsecured Notes Due 2022 and 5.0% Senior Unsecured Notes Due 2024 [Member]</link:label>
    <link:label id="lab_sm_A6125SeniorUnsecuredNotesDue2022And50SeniorUnsecuredNotesDue2024Member_documentation_en-US" xlink:label="lab_sm_A6125SeniorUnsecuredNotesDue2022And50SeniorUnsecuredNotesDue2024Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">6.125% Senior Unsecured Notes Due 2022 and 5.0% Senior Unsecured Notes Due 2024</link:label>
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    <link:label id="lab_sm_WTIHoustonMEHNYMEXWTIMember_195c3cfd-e53f-4348-b4b6-2761e6b6c4dd_terseLabel_en-US" xlink:label="lab_sm_WTIHoustonMEHNYMEXWTIMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">WTI Houston MEH NYMEX WTI</link:label>
    <link:label id="lab_sm_WTIHoustonMEHNYMEXWTIMember_label_en-US" xlink:label="lab_sm_WTIHoustonMEHNYMEXWTIMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">WTI Houston MEH NYMEX WTI [Member]</link:label>
    <link:label id="lab_sm_WTIHoustonMEHNYMEXWTIMember_documentation_en-US" xlink:label="lab_sm_WTIHoustonMEHNYMEXWTIMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">WTI Houston MEH NYMEX WTI</link:label>
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    <link:label id="lab_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_c4ddaa9e-160f-4e2f-aab3-8e7c93bb4da5_terseLabel_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Revolving credit facility, maximum loan amount</link:label>
    <link:label id="lab_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_label_en-US" xlink:label="lab_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Line of Credit Facility, Maximum Borrowing Capacity</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
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    <link:label id="lab_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_9e03efeb-7212-4706-b707-190885359d4e_verboseLabel_en-US" xlink:label="lab_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Oil, gas, and NGL production revenue</link:label>
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    <link:label id="lab_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_label_en-US" xlink:label="lab_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Revenue from Contract with Customer, Including Assessed Tax</link:label>
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    <link:label id="lab_us-gaap_SegmentReportingInformationLineItems_12cf219c-1f56-444b-973a-1cac71ec63df_terseLabel_en-US" xlink:label="lab_us-gaap_SegmentReportingInformationLineItems" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Segment Reporting Information [Line Items]</link:label>
    <link:label id="lab_us-gaap_SegmentReportingInformationLineItems_label_en-US" xlink:label="lab_us-gaap_SegmentReportingInformationLineItems" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Segment Reporting Information [Line Items]</link:label>
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    <link:label id="lab_dei_EntityAddressPostalZipCode_712a94fd-abaa-4bc3-9dc8-19d0131de618_terseLabel_en-US" xlink:label="lab_dei_EntityAddressPostalZipCode" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Entity Address, Postal Zip Code</link:label>
    <link:label id="lab_dei_EntityAddressPostalZipCode_label_en-US" xlink:label="lab_dei_EntityAddressPostalZipCode" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Entity Address, Postal Zip Code</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode" xlink:href="https://xbrl.sec.gov/dei/2021/dei-2021.xsd#dei_EntityAddressPostalZipCode"/>
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    <link:label id="lab_sm_OPISNormalButaneMontBelvieuMember_748ce842-8287-4d95-877d-3d60af75d803_terseLabel_en-US" xlink:label="lab_sm_OPISNormalButaneMontBelvieuMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">OPIS Normal Butane Mont Belvieu Non-TET [Member]</link:label>
    <link:label id="lab_sm_OPISNormalButaneMontBelvieuMember_label_en-US" xlink:label="lab_sm_OPISNormalButaneMontBelvieuMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">OPIS Normal Butane Mont Belvieu [Member]</link:label>
    <link:label id="lab_sm_OPISNormalButaneMontBelvieuMember_documentation_en-US" xlink:label="lab_sm_OPISNormalButaneMontBelvieuMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">OPIS Normal Butane Mont Belvieu</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_OPISNormalButaneMontBelvieuMember" xlink:href="sm-20210930.xsd#sm_OPISNormalButaneMontBelvieuMember"/>
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    <link:label id="lab_sm_NaturalGasRevenueMember_cfca8c81-1714-4a89-aa2c-162136d28edb_terseLabel_en-US" xlink:label="lab_sm_NaturalGasRevenueMember" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Gas production revenue</link:label>
    <link:label id="lab_sm_NaturalGasRevenueMember_label_en-US" xlink:label="lab_sm_NaturalGasRevenueMember" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Natural Gas Revenue [Member]</link:label>
    <link:label id="lab_sm_NaturalGasRevenueMember_documentation_en-US" xlink:label="lab_sm_NaturalGasRevenueMember" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">Natural Gas Revenue [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_NaturalGasRevenueMember" xlink:href="sm-20210930.xsd#sm_NaturalGasRevenueMember"/>
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    <link:label id="lab_sm_A675SeniorUnsecuredNotesDue2026Member_3e0ab71b-033f-460e-bd99-5657ba040a86_terseLabel_en-US" xlink:label="lab_sm_A675SeniorUnsecuredNotesDue2026Member" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">6.75% Senior Unsecured Notes due 2026</link:label>
    <link:label id="lab_sm_A675SeniorUnsecuredNotesDue2026Member_label_en-US" xlink:label="lab_sm_A675SeniorUnsecuredNotesDue2026Member" xlink:role="http://www.xbrl.org/2003/role/label" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">6.75% Senior Unsecured Notes Due 2026 [Member]</link:label>
    <link:label id="lab_sm_A675SeniorUnsecuredNotesDue2026Member_documentation_en-US" xlink:label="lab_sm_A675SeniorUnsecuredNotesDue2026Member" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:type="resource" xmlns:xml="http://www.w3.org/XML/1998/namespace" xml:lang="en-US">6.75% Senior Unsecured Notes Due 2026 [Member]</link:label>
    <link:loc xlink:type="locator" xlink:label="loc_sm_A675SeniorUnsecuredNotesDue2026Member" xlink:href="sm-20210930.xsd#sm_A675SeniorUnsecuredNotesDue2026Member"/>
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