This paper investigates the physics of two-phase, immiscible flow in stratified porous media. A review of previous studies reveals the major role played by the interaction of heterogeneity and viscous forces in the development of large-scale flow regimes. The stabilizing effects of gravity for flow in vertically layered porous media is introduced in a first order theoretical model and illustrated with the results of Monte Carlo simulations.
Two-phase flow; heterogeneity; Monte Carlo