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

A true-to-mechanism model is proposed, which considers steady-state two-phase ̄ow in porous media (SS2uPM) as a composition of two prototype ̄ows, namely ganglion dynamics (GD) and connected-oil pathway ̄ow (CPF). Coupling of the prototype ̄ows is e€ected with the simple rule that the macroscopic pressure gradient is the same in both. For a given set of values of the ̄ow system parameters, a domain of admissible ̄ow 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 ̄ow arrangement variables (FAV), the rate of mechanical energy dissipation, and the relative permeabilities. The new model accounts for the non-linearity of the ̄ow as well as for the e€ects of all the system parameters (notably those a€ecting interfaces), and its predictions are in very good agreement with existing data. Ó 2001 Published by Elsevier Science Ltd.