Abstract
We present a finite element scheme which combines the dual permeability method (DPM) and the extended finite element method (XFEM) to simulate coupled deformation and fluid flow in fractured porous media. The scheme incorporates spatial variability in fracture properties without requiring the fracture to be discretized or aligned with the computational mesh. DPM is used to describe the fluid flow interaction between the porous matrix and fractures, whilst XFEM is used to address the discontinuous displacement field within elements which intersect fractures. The method is strongly coupled and solves the stress and flow equations simultaneously for each time increment.
DPM-XFEM uses the level set method (LSM) to define existing fractures and eliminates the need for their explicit discretization during simulation. The method performs well on coarse structured grids and does not require complex, difficult to generate meshes to conduct simulations. Comparison between the proposed method and the discrete fracture method (DFM) shows its ability to adequately determine the displacement and fluid pore pressure distribution within a fractured domain.
