SURFACTANT/LSW FLOODING IN CARBONATES: AN INVESTIGATION OF HYBRID EOR METHOD DESIGN TO IMPROVE OIL DISPLACEMENT

Abstract

Carbonate reservoirs account for over 50% of the world’s conventional hydrocarbon reserves. Waterflooding is considered as principle IOR method in carbonates, worldwide. However, the performance of conventional waterflooding needs to be improved, concerning reservoir features. Experimental studies indicate that the efficiency of the waterflooding depends on several properties of injected water, such as ionic composition and salinity. Low-salinity waterflooding (LSWF) is a relatively recent proposed EOR technique that reduces residual oil saturation by changing the wettability to water-wet features and destabilizing oil layers. The underlying mechanisms behind surfactant injection are the abatement of interfacial tension (IFT) between crude oil and brine, wettability alteration, and an increase in the capillary number. Previous studies proved that LSWF with the combination of chemical EOR provides higher incremental oil recovery than either individual technique. Loss of surfactant due to adsorption is considered as an unfavorable phenomenon during flooding which is also affected by the application of the hybrid method....