EFFECT OF ELECTROOSMOSIS ON RELATIVE PERMEABILITIES OF SANDSTONES

Dynamic displacement experiments were performed to investigate the effect of electroosmosis on relative permeability. Berea sandstone cores, Arabian light crude oil and a 20 g/l NaCl aqueous solution were used. Direct electrical potential gradients of up to 3 V/cm were applied across the core with the cathode placed at the injection end. The application of the electrical potential gradient increased the oil relative permeability and decreased the water relative permeability. The changes in relative permeabilities increased with increasing the applied electrical potential gradient. The breakthrough water saturation at the outlet end generally shifted towards successively higher values with increasing electrical potential gradients, and the two-phase flow period increased resulting in higher breakthrough and ultimate recoveries.