CAPILLARY PRESSURE-SATURATION RELATIONS IN POROUS-MEDIA INCLUDING THEEFFECT OF WETTABILITY

In this work a functional relationship between capillary pressure and wetting phase saturation has been developed. Both the imbibition and d rainage of a wetting phase liquid into a porous medium consisting of c lean unconsolidated silica particles have been considered. In all, two bead packings, with average particle diameters of 120 mu m and 360 mu m, and three liquids-water, ethanol, and refrigerant-113-were studied . It was found that the Leverett function worked very well in describi ng the relation between capillary pressure and saturation for each liq uid using both packings; however, it did not provide adequate correlat ion for all three liquids. The functional relationship presented here considers the dependence of capillary pressure upon the contact angle of the fluid-solid interface, and also conveys how this dependence var ies with saturation. The inclusion of the contact angle dependence pro vides extension of the correlation to any wetting phase liquid of unif orm properties.