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  <xs:element id="oke_TotalAggregateMaturitiesOfLongTermDebtOutstandingAndInterestObligationsOnDebtYearFour" abstract="false" name="TotalAggregateMaturitiesOfLongTermDebtOutstandingAndInterestObligationsOnDebtYearFour" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="oke_ScheduleofIntangibleAssetsTableTextBlock" abstract="false" name="ScheduleofIntangibleAssetsTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:textBlockItemType"/>
  <xs:element id="oke_SaddlehornMember" abstract="true" name="SaddlehornMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="oke_ThirdPartyFractionationCosts" abstract="false" name="ThirdPartyFractionationCosts" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="oke_NotesPayables1Due2022Member" abstract="true" name="NotesPayables1Due2022Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oke_FederalAndStateMember" abstract="true" name="FederalAndStateMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oke_EmployeeParticipationInPlanInHundredths" abstract="false" name="EmployeeParticipationInPlanInHundredths" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="oke_DerivativePositionByTransactionTypeDomain" abstract="true" name="DerivativePositionByTransactionTypeDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="oke_TotalAggregateMaturitiesOfLongTermDebtOutstandingAndInterestObligationsOnDebtYearFive" abstract="false" name="TotalAggregateMaturitiesOfLongTermDebtOutstandingAndInterestObligationsOnDebtYearFive" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="oke_AdditionalAdjustedEBITDA" abstract="false" name="AdditionalAdjustedEBITDA" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="oke_LongtermDebtRepurchasedFaceAmount" abstract="false" name="LongtermDebtRepurchasedFaceAmount" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="oke_A3.375NotesPayabledue2022Member" abstract="true" name="A3.375NotesPayabledue2022Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oke_NorthernBorderPipelineMember" abstract="true" name="NorthernBorderPipelineMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oke_OperatingLossCarryforwardsTypeAxis" abstract="true" name="OperatingLossCarryforwardsTypeAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="oke_RevenuePerformanceObligationRemainingContractTerm" abstract="false" name="RevenuePerformanceObligationRemainingContractTerm" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="oke_StockIssuedInAcquisitionValueConversionOfAwards" abstract="false" name="StockIssuedInAcquisitionValueConversionOfAwards" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="oke_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantedinPeriodFairValue" abstract="false" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantedinPeriodFairValue" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="oke_CommodityExchangesAndImbalancesLiabilitiesCurrent" abstract="false" name="CommodityExchangesAndImbalancesLiabilitiesCurrent" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="oke_FinancialContractsMember" abstract="true" name="FinancialContractsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oke_DefinedBenefitPlanTargetAllocationPercentageofAssetsDomesticandInternationalEquities" abstract="false" name="DefinedBenefitPlanTargetAllocationPercentageofAssetsDomesticandInternationalEquities" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="oke_A4.5NotesPayabledue2050Member" abstract="true" name="A4.5NotesPayabledue2050Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oke_DurationOfHistoricalVolatility" abstract="false" name="DurationOfHistoricalVolatility" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="oke_DerivativeNotionalAmountNewContracts" abstract="false" name="DerivativeNotionalAmountNewContracts" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="oke_A485NotesPayableDue2049Member" abstract="true" name="A485NotesPayableDue2049Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="oke_MedfordIncidentAxis" abstract="true" name="MedfordIncidentAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="oke_AggregateAmountOfCommonSharesAvailableForIssuanceAndSaleUnderEquityDistributionAgreement" abstract="false" name="AggregateAmountOfCommonSharesAvailableForIssuanceAndSaleUnderEquityDistributionAgreement" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="oke_A50NotesPayableDue2026Member" abstract="true" name="A50NotesPayableDue2026Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="oke_TotalAggregateMaturitiesOfLongTermDebtOutstandingAndInterestObligationsOnDebtYearTwo" abstract="false" name="TotalAggregateMaturitiesOfLongTermDebtOutstandingAndInterestObligationsOnDebtYearTwo" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="oke_SharesSoldUnderEmployeeStockPurchasePlan" abstract="false" name="SharesSoldUnderEmployeeStockPurchasePlan" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="oke_A4.55NotesPayabledue2028Member" abstract="true" name="A4.55NotesPayabledue2028Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oke_ReplacementEquityAwardsMember" abstract="true" name="ReplacementEquityAwardsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="oke_BasicEPSfromContinuingOperationsAbstract" abstract="true" name="BasicEPSfromContinuingOperationsAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="oke_A7.5NotesPayabledue2023Member" abstract="true" name="A7.5NotesPayabledue2023Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oke_RoadrunnerGasTransmissionMember" abstract="true" name="RoadrunnerGasTransmissionMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oke_NumberOfDefinedBenefitPensionPlans" abstract="false" name="NumberOfDefinedBenefitPensionPlans" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="oke_DerivativeInstrumentByMethodForSettingNotionalAmountAxis" abstract="true" name="DerivativeInstrumentByMethodForSettingNotionalAmountAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="oke_InsuranceRecoveriesIn2022Member" abstract="true" name="InsuranceRecoveriesIn2022Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oke_IndebtednessToAdjustedEbitdaCurrent" abstract="false" name="IndebtednessToAdjustedEbitdaCurrent" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:pureItemType"/>
  <xs:element id="oke_IssuedUnderEquityAgreementMember" abstract="true" name="IssuedUnderEquityAgreementMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oke_ShareBasedPaymentArrangementShareIssueStockPriceTrigger" abstract="false" name="ShareBasedPaymentArrangementShareIssueStockPriceTrigger" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:perShareItemType"/>
  <xs:element id="oke_BusinessInterruptionSettlementProceedsMember" abstract="true" name="BusinessInterruptionSettlementProceedsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oke_DilutedEPSfromContinuingOperationsAbstract" abstract="true" name="DilutedEPSfromContinuingOperationsAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="oke_TotalReceivables2022Member" abstract="true" name="TotalReceivables2022Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oke_PowerGWsMember" abstract="true" name="PowerGWsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="oke_NaturalGasLiquidsDomain" abstract="true" name="NaturalGasLiquidsDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oke_NotesPayableDue2025Member" abstract="true" name="NotesPayableDue2025Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oke_BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuableEntitySharesIssuedPerAcquireeShare" abstract="false" name="BusinessCombinationConsiderationTransferredEquityInterestsIssuedAndIssuableEntitySharesIssuedPerAcquireeShare" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="oke_NaturalGasGatheringandProcessingIntersegmentMember" abstract="true" name="NaturalGasGatheringandProcessingIntersegmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oke_DerivativeInstrumentByMethodForSettingNotionalAmountDomain" abstract="true" name="DerivativeInstrumentByMethodForSettingNotionalAmountDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oke_CoverageOfPipelineAcquisition" abstract="false" name="CoverageOfPipelineAcquisition" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="oke_A61NotesPayableDue2032Member" abstract="true" name="A61NotesPayableDue2032Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oke_A5.0NotesPayabledue2023Member" abstract="true" name="A5.0NotesPayabledue2023Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oke_DerivativesByCommodityAxis" abstract="true" name="DerivativesByCommodityAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="oke_DefinedBenefitPlanTargetAllocationPercentageOfAssetsTotal" abstract="false" name="DefinedBenefitPlanTargetAllocationPercentageOfAssetsTotal" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="oke_OperatingLossCarryforwardsIndefiniteCarryforwardPeriodMember" abstract="true" name="OperatingLossCarryforwardsIndefiniteCarryforwardPeriodMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="oke_NaturalGasPipelinesMember" abstract="true" name="NaturalGasPipelinesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oke_IntersegmentRevenuesByNameDomain" abstract="true" name="IntersegmentRevenuesByNameDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="oke_IntersegmentRevenuesbyNameAxis" abstract="true" name="IntersegmentRevenuesbyNameAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="oke_FinancialDerivativeInstrumentMember" abstract="true" name="FinancialDerivativeInstrumentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oke_UnamortizedPortionOfDebtIssuanceCostsAndTerminatedSwaps" abstract="false" name="UnamortizedPortionOfDebtIssuanceCostsAndTerminatedSwaps" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="oke_ServicesMember" abstract="true" name="ServicesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oke_MedfordIncidentMember" abstract="true" name="MedfordIncidentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oke_A64NotesPayableDueMay2037Member" abstract="true" name="A64NotesPayableDueMay2037Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="oke_NumberOfUnconsolidatedAffiliates" abstract="false" name="NumberOfUnconsolidatedAffiliates" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="oke_NaturalGasLiquidsRefinedProductsAndCrudeOilMember" abstract="true" name="NaturalGasLiquidsRefinedProductsAndCrudeOilMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="oke_BridgeTexMember" abstract="true" name="BridgeTexMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="oke_A5.2NotesPayabledue2048Member" abstract="true" name="A5.2NotesPayabledue2048Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oke_A42NotesPayableDue2047Member" abstract="true" name="A42NotesPayableDue2047Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="oke_CrudeOilPipelineLength" abstract="false" name="CrudeOilPipelineLength" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="oke_DefinedBenefitPlanTargetAllocationPercentageOfAssetsRealEstate" abstract="false" name="DefinedBenefitPlanTargetAllocationPercentageOfAssetsRealEstate" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="oke_OperatingStorageCapacity" abstract="false" name="OperatingStorageCapacity" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:volumeItemType"/>
  <xs:element id="oke_InterestRateSwapsAndTreasuryLocksMember" abstract="true" name="InterestRateSwapsAndTreasuryLocksMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="oke_A5.85NotesPayabledue2026Member" abstract="true" name="A5.85NotesPayabledue2026Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oke_NaturalGasLiquidsMember" abstract="true" name="NaturalGasLiquidsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oke_ConstructionContracts1Member" abstract="true" name="ConstructionContracts1Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="oke_A6.2NotesPayabledue2043Member" abstract="true" name="A6.2NotesPayabledue2043Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oke_FixedPriceMember" abstract="true" name="FixedPriceMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
</xs:schema>
