Coupled Discrete Crack and Porous Media Model for Hydraulic Fractures using the XFEM
A hydromechanical model for investigating fluid flow in the fractured porous media is presented in this study. The hydromechanical coupling equations are derived from the mass and momentum balance equation for the saturated porous media. The extended finite element method is employed to model the discontinuity for fluid flow and cracks inside the porous media. The Newton-Raphson method is utilized for solving the nonlinear coupling equation with an implicit time integration scheme. Finally, examples are presented to demonstrate the effectiveness of the presented model. Fracture propagation in the porous media under the influence of the preexisted pressurized zone is also studied. It is found that the cracks and preexisted pressurized region have a significant impact on the fluid flow and deformation patterns.
Keywords: hydromechanical model, porous media, hydraulic fracturing, XFEM, discrete crack