Viscosity Reduction WAG: An Effective EOR Process for North Slope Viscous Oils

Abstract A novel EOR method, Viscosity Reducing Water-Alternating-Gas injection (VR-WAG), has been developed to improve oil recovery from viscous oil reservoirs and under-saturated light oil reservoirs. Heavy components are mixed with produced lean gas to manufacture viscosity-reducing injectant (VRI). When VRI is injected into a heavy oil reservoir, oil viscosity can be reduced by up to 90% and the oil recovery can be improved by 15-20%. VR-WAG may be widely applied in Alaska's heavy oils. The first enriched gas application will be the West Sak 1-J EOR Project (WS-1J) at Kuparuk. Additional projects are likely to utilize VR-WAG, including the Prudhoe Bay satellite fields, Orion and Polaris, and the S-pad EOR Project at Milne Point. Laboratory experimental data, numerical simulation results, and potential project scopes from each of these fields are included.