FLOODING WITH MICELLAR SYSTEMS AFFECTED BY COSURFACTANTS

1520563 Oil recovery MARATHON OIL CO 22 June 1976 [11 Aug 1975] 25904/76 Heading E1F In an oil recovery process, the viscosity of a micellar dispersion comprising a hydrocarbon, surfactant, cosurfactant and water is determined by the hydrophilicy of the cosurfactant. Preferably the dispersion comprises 4-20% by volume surfactant, 4-86% by volume hydrocarbon, 10-92% by volume water, 0.01-20% by volume cosurfactant and 0.001-10% by volume electrolyte. The surfactant may be anionic, cationic, nonionic or mixtures thereof and is preferably a petroleum sulphonate. The hydrocarbon may be crude oil, a fraction thereof, unreacted vehicle oil within the surfactant, synthesised hydrocarbons, or mixtures thereof; and the electrolyte may be water-soluble inorganic salts, inorganic bases, inorganic acids or mixtures thereof and is preferably ammonium sulphate or sulphite, or sodium sulphate or sulphite. The cosurfactant may be an amide, amino compound, ester, aldehyde, or ketone and is preferably an alcohol.