热流固-损伤多场耦合作用下干热岩水力压裂特征数值模拟

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中图分类号：TK521 文献标志码：A

Abstract：Hydraulic fracturing serves asacritical pathwayfortheeficient developmentofdryhotrockresources，and itscore processinvolves theinjectionoflowtemperatureandhigh-pressrefluidsintohigh-temperature，hig-stresrock foratios，in which coldshock-induced thermal stresscan playavitalroleinfracture initiationand propagationwithinthehotdryrock. However，theevolution characteristicsof stre/temperature and fracturepropagation patterns inhigh-temperaturerock matrix undercoupled thermo-stressinteractionsremainunclear.Inthisstudy，a thermo-hydro-mechanical-damagecoupledfracture propagationdelwastablised，corporatingwelloresresssuperpositioneects，rocktero-poroelasticespons，ela tic-britlefailurecriteriaandpermeability-porosityvariationswithmatrixdamage.Themodel'saccuracywasvalidatedhroughcomparisons withtheresultsofanalyticalsolutions forwelborecoolingandfracturepropagation.Numerical simulationsunder varyinggeothermalstressconditionsandfluid injection temperaturerevealthat，duringfracture initiation，trong thermalstresses nearthe welborecan promotemulti-directional fractureextension，whilethesubsequentpropagation becomes increasingly dominatedbyin-situstressdistribution，causingfracturereorientationtowards themaximum principal stress direction，whilethe variationof temperatureislocalizednearthewelloreregion.Largertemperaturediferentialscanenhancethermal stresses，reduce nitiationpressuresandfaciliatethedevelopment ofcomplexfracture networks.Smaller in-situ stressdiferetials（under constantmaximum principal stress）can weaken thecontrolof fracture initiation/propagationdirections bystressfield，promting the formation of complex fracture networks while inducing greater stress perturbations.

Keywords：hotdryrock；hydraulicfracturing;thermal-hydraulic-mechanical-damagecoupling model;thermalstress；in-situdifferential stress ； breakdown pressure； fracture propagation patterns

干热岩（hot dryrock，HDR）地热资源储量大、分布广，是一种极具潜力的可再生清洁能源。（剩余14898字）