Crude Oil-in-water Emulsion Flooding for EOR

Injection of oil-in-water emulsions has been identified as an effective oil recovery method. McAuliffe (1973) introduced emulsion injection as a mean to increase sweep efficiency. McAuliffe compared dilute emulsion flooding to water flooding to show that injection of emulsion into sandstone cores improved sweep efficiency. In this study, alaboratory investigation is performed to characterize crude oil-in-water emulsion and to evaluate the emulsion injection to improve oil recovery. The experiments consist of injecting crude oil-in-water emulsion with known droplet size distribution through Berea cores with different permeability values to explore the effect of drop to pore throat size ratio on the effectiveness of emulsion flooding. Results show that crude oil-in-water emulsion can effectively increase oil recovery. The blockage phenomena caused by emulsion injection can be effective even when emulsion is chased by waterflooding, but the response is a function of capillary number.