The Statistical Damage Constitutive Model of Longmaxi Shale under High Temperature and High Pressure

Abstract In the exploitation of shale gas in deep and ultradeep formations, mechanical properties change under action high temperature pressure. High-temperature stimulation can effectively release damage water phase trapping, which was caused during drilling completion hydraulic fracturing reservoirs. this paper, experiments have twelve groups samples (three per group) four target temperatures, 25, 200, 400, 600°C as well confining pressure set 0 MPa, 15 30 MPa. The servo testing machine is used to perform triaxial compression tests on specimens that undergone temperature. porosity, permeability, velocity are also obtained different temperatures. A statistical constitutive model after thermal established. Based characteristics random distribution rock strength strain theory, apply relevant knowledge mechanics consider failure microprotocol nonlinear relationship between elastic modulus According test results, parameters discussed. considering given also; a comparison with results uniaxial shows rationality reliability. This work not only enriches theory pattern but contributes development at