Computation of Capillary Pressure and Global Mobility From Spontaneous Water Imbibition Into Oil-Saturated Rock

Abstract

Summary An approach was developed to extract the imbibition capillary pressure and the global mobility data from spontaneous water imbibition tests in oil/water/rock systems. Capillary pressure and global mobility data were calculated using this method with the experimental data of countercurrent spontaneous water imbibition tests in different rocks and at different interfacial tensions. The calculated capillary pressures were consistent with the change in interfacial tension. The oil/water/rock systems with greater interfacial tensions had greater capillary pressures. However, the oil/water/rock systems with greater capillary pressure may not have greater imbibition rate. The calculated values of the global mobility and the imbibition index explain why the oil recovery or the imbibition rate in systems with high interfacial tension was smaller than that in systems with low interfacial tension, which has been considered a paradoxical result for many years.