Reservoir simulation of fractured media in compressible single-phase flow in 2D, 2.5D and 3D unstructured gridding

摘要

This work presents an efficient and accurate algorithm for multicomponent compressible single-phase flow in fractured media. The model covers 2D, 2.5D and 3D unstructured gridding and accounts for heterogeneity and anisotropy. The fracture cross-flow equilibrium approach (FCFE) is applied in triangular finite elements (FE) in 2D and prism and tetrahedra (FE) in 2.5D and 3D, respectively. One can then simulate flow in fractured media with fractures in different orientations. Unstructured gridding with FCFE allows simulating realistic fractured porous media efficiently. In addition, FCFE in unstructured gridding alleviates the limitation of the number of intersecting fractures. In rectangular and hexahedron FE, the number is limited to 2 in 2D and 3 in 3D. To generate domains with complicated boundaries, we have developed a computer-aided design (CAD) interface. We demonstrate the efficiency and accuracy of our model by several numerical examples. Our examples include comparison with analytical solution and convergence rate.