Modelling two-phase equilibrium in three-dimensional porous microstructures

This work presents a methodology for determining the interface between wett ing and non-wetting phases inside a three-dimensional (3D) porous space at a given equilibrium state. The work is limited to the study of mechanical e quilibrium. Mass transfer between different phases is not considered. The m ethod is based on a 3D extension of the opening: method from image analysis , applied on 3D stochastically reconstructed porous microstructures. The ad vantage of the presently proposed methodology with respect to percolation n etworks conception is that simplifying assumptions regarding the geometry o f the porous space are not required. In fact, invasion of wetting fluid int o a real porous structure in imbibition and wetting fluid retention at the later stages of drainage occur spatially through a complex structure of cor ners and intrinsic irregularities of pore surfaces that are very difficult to model by using percolation networks. Simulation results were compared wi th experimental data related to mercury intrusion and water-oil capillary c urves for a Berea sandstone. (C) 1999 Elsevier Science Ltd. All rights rese rved.