环空压力对固井界面完整性的影响分析

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中图分类号：TE21 文献标志码：A 文章编号：2095-2945(2025)27-0092-05

Abstract:Duringshalegaswelsmulti-stagefracturing caneasilyleadtowelboresealing filureandthuscreatea sustainedcasing presure(SCP)problem.Inordertoensurethewelboresafeproduction,whentheSCPreachesthewellhead permisiblepressure,itwillbereleased,andthefrequentpresurereleasewillsubjectthecementinginterfacetoalterating stress，whichmayleadtothecementinginterfacedebonding.Therefore，basedonthedamagemechanicsandfiniteelement method,athree-dimensionalumericalmodelofcasing-cementsheathformationwithanularbyinsertingazero-thickness cohesiveelementbetweencementingintefaceswasestablished，andtheefectsofannularpresureandinterfacestrengthonthe cementinginterfacesintegritywereexplored.Theresultsofthestudyshowedthattheinterfacialdamageareaanddegree graduallyincreaseswiththeincreaseofannularpresureandthenumberofpresurzation-relief times;improvingtheinterface strengthcanefectivelyreducetheareaanddegreeofintefacialdamageandensuretheefectivesealingofthecement sheath. Theshearstrengthofthecementsheath-formationinterfacehaslitleeffectoninterfacedamage,，butwhentheshearstrengthof thecasing-cementsheath interfaceisincreaseditcanefectivelyreducethedegreeandareaof interfacedamage，ensurethe cementseatheffectivesealingduring theanularpressurefrequentreliefandpresurization.Theaboveworkisofsome reference significance for the research on the SCP safety evaluation.

Keywords:shale gaswell;annular pressure;cementing interface； integrity； interface damage;sealing failure

页岩气作为非常规油气，常通过体积压裂技术实现对储层的改造，提高产量及采收率[1-。（剩余10138字）