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

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.Digitized from paper copies provided by the Department of Hydrology & Atmospheric Sciences