RECOVERY OF VISCOSITY-INCREASING SURFACTANTS IN FLUIDS FOR ACTION ON FORMATION AFTER EXPOSURE TO SHEAR FORCE Russian patent published in 2022 - IPC E21B43/22 C09K8/60 

FIELD: oil industry.

SUBSTANCE: invention relates to production of surface-active fluids increasing oil recovery. Method for reducing recovery time of a fluid system with a viscosity-increasing surfactant after exposure to a shear force involves introduction of a system of fluid medium with a viscosity increasing surfactant into a subterranean formation. Said fluid medium contains a surfactant and a hydrophobically modified associative polymer in concentration of 0.005 to 0.1 wt %. Said hydrophobically modified associative polymer contains: at least one water-soluble portion selected from a group, consisting of acrylamide, methacrylamide, acrylic acid, methacrylic acid, 2-acrylamidomethylpropane sulphonic acid, N-vinylpyrrolidone, N-vinylformamide and mixtures of said compounds; and at least one water-insoluble portion selected from the group consisting of ethylhexyl acrylate, stearyl acrylate, octadecyldimethylallylammonium chloride, n-lauryl-2-methylacrylamide and mixtures of said compounds.

EFFECT: high level of viscosity characteristics of fluid medium at high temperatures and reduced time of recovery after exposure to shear force.

8 cl, 1 tbl, 1 ex