True-to-mechanism model of steady-state two-phase flow in porous media, using decomposition into prototype flows

A true-to-mechanism model is proposed, which considers steady-state two-phase flow in porous media (SS2 phi PM) as a composition of two prototype flows, namely ganglion dynamics (GD) and connected-oil pathway flow (CPF). Coupling of the prototype flows is effected with the simple rule that the macroscopic pressure gradient is the same in both. For a given set of values of the flow system parameters, a domain of admissible flow combinations is obtained. The solution is determined by assuming that each point in this domain has equal probability of being 'visited'. This leads to unique values for the flow arrangement variables (FAV), the rate of mechanical energy dissipation, and the relative permeabilities. The new model accounts for the non-linearity of the flow as well as for the effects of all the system parameters (notably those affecting interfaces), and its predictions are in very good agreement with existing data. (C) 2001 Published by Elsevier Science Ltd.