Experimental and Theoretical Basis for a Wettability-Interfacial Area-Relative Permeability Relationship

摘要

Using an interfacial tracer technique, our experiments showqualitatively different trends of total interfacial area betweenthe wetting and non-wetting phases as a function of saturation,depending on whether the system is strongly or weaklywetted. A strongly wetted system is defined as one in whichthe wetting phase can spread as a thin film on the solidsurface. We assess the relative contributions of fluid/fluid andfluid/solid interfaces to the total area using thermodynamicarguments. The fluid/solid contribution to area plays a crucialrole in explaining the measurements.The influence of interfacial area on relative permeability is notstraightforward. Simple analysis based upon pore-leveldistribution of phases in a model porous medium allowsquantifying the differences in the relative permeabilities forboth weakly and strongly wetted systems, measuredsimultaneously with the interfacial area. Relative permeabilitycorrelates with fluid/solid area but not with fluid/fluidinterfacial area.