Extended finite element modeling of production from a reservoir embedded with an arbitrary fracture network

A numerical scheme based on the eXtended Finite Element Method (XFEM) is proposed to simulate complex fluid flow in a fractured porous reservoir. By enriching the elements fully cut by the fracture and the near-tip region, the flow mechanism including the tip flux singularity can be exactly represented in the XFEM formulation. Fluid transfer between the matrix and the fractures can be easily coupled, and XFEM also overcomes the sensitivity to the mesh used in the traditional unstructured discretizations, regardless of the complexity of the fracture network. The method is validated for a simple case by the exact analytical solution. Results are compared between XFEM and FEM. Case studies are presented to illustrate the power, efficiency, accuracy, and flexibility of the proposed method for simulating transient productive flow in reservoirs with complex fracture networks.