Simulation of liquid-liquid interfaces in porous media

The properties of the interface of two immiscible fluids play an important role in several processes such as membrane supported liquid extraction, enhance oil recovery, aquifer remediation, etc. In this paper the spatial distribution of two immiscible liquids in non-dispersive contact via a porous media is studied by using numerical simulations. The simulations are carried at pore-scale by minimizing the total interfacial energy using the simulated annealing method. This technique allows us to compute the spatial distribution of fluids in the pores without assuming the geometry of the solid or the interface. The studied solids are made of randomly packed spheres either monodispersed or bi-dispersed. The effect of pore size distribution, tortuosity, porosity and contact angle on the liquid-liquid interface extent and geometry is analyzed. The simulations demonstrate that liquid-liquid interface follows a simple linear correlation with the contact angle. At low contact angle the wetting phase extents into the non-wetting phase forming pendular liquid bridges. The continuity of the phases is evaluated. The liquid-liquid interface is mostly continuous for all the contact angles. (C) 2015 Elsevier B.V. All rights reserved.