Selecting salinities in micellar flooding

Abstract From the Canadian patent

In the displacement of crude oil through a subterranean reservoir with an aqueous displacement fluid improved oil recovery is obtained by providing a salinity contrast between the displacement fluid and aqueous formation fluid. The salinity of the displacement fluid is selected such that at least one mixture of the aqueous displacement and the aqueous formation fluid will have the minimum interfacial tension between the displaced crude oil and mixtures of these fluids. The minimum interfacial tension between crude oil and mixtures of aqueous displacement and formation fluids can be determined by mixing these fluids such that some mixtures contain from essentially none to essentially all …