| 摘 要： | The plastic deformation and numerous natural joints of shale pose a great challenge for the predic⁃ tion of the hydraulic fracture geometry extension. Based on the finite element method, a fully coupled numeri⁃ cal model for elastoplastic hydraulic fractures was established with natural fractures and bedding planes consid⁃ ered. The numerical model was validated with the KGD analytical solution and Blanton’s curve. The numerical results show that, compared with the numerical model solution of linear elasticity, the hydraulic fractures are prone to enter the natural weak interface due to the rock plastic deformation. The rock plastic deformation area mainly lies in the reservoir layer during the fracture propagation. In the case of rock ductile damage, the hy⁃ draulic fracture is more likely to penetrate the bedding plane. Hydraulic fractures can directly penetrate natural fractures and bedding planes at high injection rates due to large driving forces. The study provides new insights in terms of hydraulic fracture extension in elastoplastic formations. © 2023 Editorial Office of Applied Mathematics and Mechanics. All rights reserved.
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