OIL PRODUCTION USING MULTISTAGE SURFACTANT POLYMER CHEMICAL FLOOD

摘要

A process for recovering oil from an oil-bearing formation is disclosed comprising providing a first oil recovery formulation comprising a first surfactant able to create low interfacial tension with reservoir crude oil; injecting the first oil recovery formulation into the oil-bearing formation via an injection well (201); providing a second oil recovery formulation having a second surfactant with a higher solubility in water than the first formulation; injecting the second oil recovery formulation into the oil-bearing formation via the injection well; and producing oil to a production well (203).