Back to results
US 4,284,517 AGranted
Oil recovery by waterflooding employing anionic polymeric surfactants
AssigneeMobil Oil Corporation
InventorsCatherine S. H. Chen, Edward W. Sheppard
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeMobil Oil Corporation
InventorsCatherine S. H. Chen, Edward W. Sheppard
Estimating the term…
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.
In a method for the recovery of oil from a subterranean oil reservoir penetrated by spaced injection and production systems in which an aqueous fluid is introduced into said reservoir via said injection system to displace oil to said production system, the improvement comprising including in said fluid an anionic surfactant in an amount sufficient to reduce the interfacial tension between oil and water to less than 0.1 dyne per centimeter, said anionic surfactant comprising the polymeric reaction product of:
In a method for the recovery of oil from a subterranean oil reservoir penetrated by spaced injection and production systems in which an aqueous fluid is introduced into said reservoir via said injection system to displace oil to said production system, the improvement comprising including in said fluid anionic surfactant in an amount sufficient to reduce the interfacial tension between oil and water to less than 0.1 dyne per centimeter, said anionic surfactant comprising a water soluble styrene-maleic anhydride copolymer in which at least 20 mol percent of the anhydride groups have been converted into succinimide or succinamide groups by reacting said anhydride groups with a primary amine, said amine having the formula:
Dependencies are inferred from the claim text.