Oil recovery by waterflooding employing succinimido aryl sulfonate

Abstract

A method for the recovery of oil from an oil-containing subterranean formation by waterflooding employing as an injection medium an aqueous solution of an anionic surfactant comprising a hydrocarbyl substituted succinimido aryl sulfonate and/or its succinamic acid derivative. Such surfactants retain their detergency and do not precipitate in aqueous systems containing high concentrations of brine, e.g., over 20,000 ppm Ca.sup.++, over 10,000 ppm Mg.sup.++ and over 50,000 ppm Na.sup.+. These surfactants are effective in mobilizing tertiary oil under highly saline environments and demonstrate low adsorptive losses. When used as cosurfactants, these materials significantly improve the brine tolerance of more sensitive surfactants, such as petroleum sulfonates. In accordance with one form of the invention, the solution of a minor amount of such surfactants with petroleum sulfonates increased the tolerance of the petroleum sulfonates four-fold with respect to sodium ions and seventy-fold with respect to calcium and magnesium ions. According to a preferred form of the invention, the surfactants comprise the condensation products of a C.sub.10 -C.sub.50 hydrocarbyl substituted succinic anhydride with either an aminobenzenedisulfonic acid or an amino naphthalene di- or tri-sulfonic acid.