Ultra-deep shale gas wells are susceptible to deformation damage of casing during the perforating process. Taking the exploitation of ultra-deep shale gas wells in the Longquan-Jianyang block of the Sichuan Basin as an example, focusing on the change of casing stress during perforation, considering the interaction of non-uniform ground stress, perforation explosion temperature field and detonation pressure field in shale formation, the finite element software was used to build a calculation model of perforated casing stress in ultra-deep shale gas wells and conduct a mechanical performance test to investigate the influence of working condition parameters, cement sheath parameters and perforating parameters on casing stress. The results show that, in the cementing process design, the elastic modulus of cement sheath should be greater than 5 GPa, the Poisson's ratio of cement sheath be minimized, and the thickness of cement sheath be increased. In the perforating process design, the perforation diameter should be controlled between 10 mm and 16 mm, the high density (˃24 perforations per meter) perforating process be selected, and the perforating phase angle be 120° and 180°.The research results provide theoretical basis for the optimization of design parameters of cementing and perforating operations in ultra-deep wells.
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