Mobil Oil Corporation

Edward W Sheppard

Catherine S Chen

Frederick C Schwab

Don E Byham

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 polymeric surfactant formed by reacting a polymer including succinic anhydride moieties with a primary amine to provide a polymeric reaction product in which at least 20 mol percent of the anhydride moieties have been converted, by reaction with said amine, to succinimide or succinamide groups. The polymeric anionic surfactants of the invention exhibit good physical and chemical stability, are shear stable, are effective in maintaining the salt stability of other surfactants (such as petroleum sulfonates) and also function as viscosifiers, even in the presence of significant concentrations of divalent metal ions. According to a preferred form of the invention, the surfactants comprise the reaction product of a copolymer of styrene and maleic anhydride and triethylammonium aniline disulfonate, in which reaction product from 20 mol percent to 40 mol percent of the anhydride moieties have been converted to succinimide or succinamide groups.

Oil recovery by waterflooding employing an anionic polymeric surfactant

Oil recovery by waterflooding employing anionic polymeric surfactants

Waterflood oil recovery process involving the use of an amphoteric polyelectrolyte as a thickening agent for mobility control. The amphoteric polyelectrolyte is a copolymer of a quaternary vinyl pyridinium sulfonate and a water-insoluble alpha olefin or hydrogenated diene. Specifically disclosed are vinyl pyridinium sulfonate-styrene block copolymers. The amphoteric polyelectrolytes are stable in high temperature and high brine environments.

Oil recovery process involving the injection of thickened water

This specification discloses a waterflooding process for producing oil from an oil-containing subterranean formation that is penetrated by an injection well and a production well. An aqueous solution of a water soluble copolymer having segments formed of blocks of an aromatic monomer and blocks of an olefinic monomer chemically modified to have an anionic function on the olefinic segments is injected into the formation to improve the recovery of oil therefrom.

Waterflooding process employing anionic-nonionic copolymer

This specification discloses a waterflooding process for producing oil from an oil-containing subterranean formation penetrated by an injection well and a production well. An aqueous solution of a copolymer formed of hydrophobic olefinic segments and cationic aromatic hydrophilic segments is injected into and driven through the formation in the production of oil therefrom.

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Lambertville, NJ, United States of America

Edward W Sheppard