Numerical Modelling of Two-Phase Flow in Heterogeneous, Anisotropic Porous Media

Abstract

A numerical model for flow of two immiscible, incompressible fluids in a two-dimensional, incompressible, heterogeneous, and possibly anisotropic porous medium is developed. The numerical model actually incorporates two different formulations. One formulation solves for the wetting-phase pressure and saturation as primary unknowns, while the other formulation solves for the wetting-phase pressure and capillary pressure. Both formulations of the model are verified through comparison with an analytical solution for two-phase flow. The formulations exhibit differing degrees of internal mass balance. One of the model formulations is used to simulate a laboratory experiment involving the inundation of a heterogeneous sand pack by tetrachloroethylene (PCE). PCE distributions implied by the numerical model agree reasonably well with observed distributions, although no quantitative distribution data were available.