Permeability analysis of fractured vuggy porous media based on homogenization theory

Based on the characteristics of fractured vuggy porous media, a novel mathematical model was proposed to model fluid flow in such media on fine scale, i.e., the discrete fracture-vug network model. The new model consists of three systems: porous rock system, fracture system, and vug system. The fractures and vugs are embedded in porous rock, and the isolated vugs could be connected via the discrete fracture network. The flow in porous rock and fractures follows Darcy's law, and the vugs system is free fluid region. Using a two-scale homogenization limit theory, we obtained a macroscopic Darcy's law governing the media on coarse scale. The theoretical formula of the equivalent permeability of the fractured vuggy porous media was derived. The model and method of this paper were verified by some numerical examples. At the end the permeability of some fractured vuggy porous media with typical fracture-vug structures was analyzed.