Lattice Boltzmann modeling and evaluation of fluid flow in heterogeneous porous media involving multiple matrix constituents

Geomaterials are typical heterogeneous porous media involving multiple types of matrix constituents which dominate the subsurface flow behavior. An improved lattice Boltzmann method (LBM) approach is developed for analyzing the detailed flow characteristics through multiple matrix constituents, investigating sample size effects on the permeability variation, and evaluating characteristic information at the representative elementary volume (REV) scale for the macroscale reference. Applications are conducted in both 2D and 3D to numerically investigate the impact of geometric topology and matrix property on the detailed velocity field, and effects of sample sizes on the permeability for evaluating effective REV scale fluid flow parameters. The simulation results demonstrate that the improved LBM approach is able to quantitatively describe and simulate complex fluid flow through multiple-matrix constructed heterogeneous porous media, which provides more realistic simulation results for up-scaled research and engineering.