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ASolutionWhichEnablesContinuedSafeProductioninWellswithUnplannedTCAorCCAPressureAllrightsreservedPetroleumTechnologyCompany(hereinafterPTC)2016.Reproduction,distributionorstorageofanykindwithoutthewrittenconsentfromPTCisprohibited.AbstractSustained casing/casing annulus (CCA) or tubing/casing annulus (TCA) pressure is a common well integritymanagementchallenge.Itoftenresultsinwellsbeingclosedinpendingworkover.Thiswhitepaperdescribesanewuseforfieldproventechnologies,whichcanallowproductiontocontinue,whilecostlyworkoverscanbedelayedorinsomecasesavoided.WhyWellswithUnplannedPressureintheTCA/CCAareClosedin?UnplannedTCApressureisusuallyaresultofaleakinacompletioncomponentorlinertoppacker,whileunplannedCCApressureisusuallyduetoacementationfailure.MostOPCO’sfollowa‘doublebarrierenvelope’wellintegritypolicy, where these items are elements of the ‘primary barrier envelope’. If the double barrier policy iscompromised, it is usually necessary to close in the well, while awaiting workover to identify and address theproblematicbarrierelement.HowarewellswithPlannedPressureintheTCAManaged?Gas Lifted wells were historically the highest risk wells with planned TCA pressure. Over recent years newtechnologieshavebeenadopted,whichnowensurearobustdoublebarrierenvelopeisinplacetomitigateagainstthereleaseofliftgasfromtheTCA.

The technologies take advantage of the threaded profile (the VR profile), which ismachinedintobothsideoutletsonallwellheads.Specifically,a‘wellbarrierelementqualified’Pressure/Temperaturesensor‘VRSense’[1] is installed in one of the VR profiles, and a hydraulically actuated ‘Master SurfaceAnnulusSafety’(MSAS)valve(withsimilarfunctionalitytoasubsurfacesafetyvalve) isinstalledintheother.They,alongwiththewellheadandproductioncasing,combinetoformaprimarybarrierenvelopearoundthepressurizedTCA. Theoutercasingstringandassociatedwellheadand valves in the first casing / casing annulus (CCA1), forms the secondary barrierenvelope.

UsingVRSenseandMSASonwellswithunplannedTCA/CCApressureThe approach used in gas lifted wells can, without the need for a workover, be used on wells with unplannedTCA/CCA pressure. By restoring double barrier integrity in this way, continued production while planning theworkovercanbefacilitated,orinsomecasestheneedforworkoveravoided,deliveringsignificantcostsavings.Theonlydifferenceisthatinthecaseofgasliftedwells,theplannedannuluspressureisknown,sotheoutercasingstringpressureratingisspecifiedaccordingly.InwellswithunplannedTCA/CCApressure, theTCA/CCApressuremustbemanagedbelowthemaximum allowable pressure of the installednextoutercasing.This canbeachievedusingahydraulic control power unit (HCPU), whichreadsannuluspressuredataprovidedbytheVRSense. The HCPU can be programmed so thatwhenMAASP is approached, theMSASvalve isopened to automatically bleed off the annuluspressuretoasuitablelocation.[1]PTCWhitePaper:AnewApproachtoAnnulusPressureMonitoring:ImprovingDataReliabilityandWellIntegrity,whileReducingLifecycleCosts

MSASG

VRSense

Copyright©PetroleumTechnologyCompany2016