Prediction of three-phase relative permeabilities using a pore-scale network model anchored to two-phase data

A first attempt has been made to predict three-phase relative permeability experimental data of a water-wet Berea sandstone obtained by Oak (1990) using the three-phase flow network model for arbitrary wettability developed by van Dijke and Sorbie (2002a). First, the network model is anchored to the corresponding two-phase relative permeability and capillary pressure data using an idealized representation of the pore geometry and a simple parameter-fitting procedure. Then, predictions of three-phase properties are made, which are compared with experimental data as well as previous predictions from different network models. The present study has confirmed that the relatively simple network model, anchored to experimental data, is able to predict three-phase relative permeabilities with reasonable accuracy, comparable to the accuracy of more-complex models. On the basis of these preliminary results, a limited sensitivity study is carried out with respect to different wettability states and two combinations of interfacial tensions (IFTs). This study reveals some new results with respect to the invariance of relative permeability to interfacial-tension combinations and the trend of water relative permeability as a function of the fraction of oil-wet pores in systems of nonuniform wettability. Copyright © 2007 Society of Petroleum Engineers.