Oil recovery process employing cyclic wettability alteration

Abstract From the Canadian patent

Docket 870037-A, OIL RECOVERY PROCESS EMPLOYING CYCLIC WETTABLILITY ALTERATION ABSTRACT, A surfactant solution is injected into an oil-wet fractured formation and becomes the preferred wetting phase of the matrix blocks in the formation thereby displacing oil from the matrix blocks into the fracture network. The formation is then flooded with water to displace the oil from the fracture network to the surface while returning the matrix blocks to an oil-wet condition. The injection cycle is repeated until the formation is depleted.