METHOD FOR DEVELOPING AN OIL RESERVOIR THAT IS HETEROGENEOUS IN TERMS OF PERMEABILITY Russian patent published in 2022 - IPC E21B43/22 E21B43/16 C09K8/584 

FIELD: oil industry.

SUBSTANCE: invention relates to the development of an oil field and can be used in the development of oil deposits with heterogeneous permeability formations to control the injectivity profile of an injection well, increase the oil displacement efficiency by involving low-permeability oil-saturated formation zones that were not previously affected. A method for developing an oil reservoir that is heterogeneous in permeability includes determining the injectivity of an injection well, pumping a rim of an invert emulsion containing an emulsifier and an aqueous solution, a composition consisting of oxyethylated alkylphenol AF9-6 and oleic acid in a ratio of 2:1, as well as a benzene-containing fraction is used as an emulsifier , and the total concentration of ethoxylated alkylphenol AF9-6 and oleic acid in the emulsifier is 15-39%, the rest is the benzene-containing fraction, mineralized water is used as an aqueous solution. When the injectivity of the injection well is below 250 m³/day, a slug of emulsion polymer is pumped into the injection well at the following ratio of components, wt.%: polyacrylamide 0.1-0.2, hydrocarbon solvent 18.7-29.7, surfactant 2, 2-4.95, water - the rest, while a mixture of hydrocarbons of the limiting aliphatic and aromatic series is used as a hydrocarbon solvent, alkylphenol with a carbon chain length of C-9 and a degree of oxyethylation of 6 is used as a surfactant, the emulsion polymer slug is pressed into formation with mineralized water with a density of 1060 to 1190 kg/m³, in a volume of 0.5-1 of the volume of the invert emulsion slug, then the invert emulsion slug is injected, the ratio of the emulsion polymer slug and the invert emulsion is (from 4 to 5): 1. When the injectivity of the injection well is higher than or equal to 250 m³/day, an invert emulsion slug is injected into the injection well, the invert emulsion slug is forced into the formation with mineralized water with a density of 1060 to 1190 kg/m³, in a volume of 0.5-1 of the volume of the invert emulsion slug, then a slug of emulsion polymer is pumped in with the following ratio of components, wt.%: polyacrylamide 0.1-0.2, hydrocarbon solvent 18.7-29.7, surfactant 2.2-4.95, water - the rest, with in this case, a mixture of hydrocarbons of the limiting aliphatic and aromatic series is used as a hydrocarbon solvent, alkylphenol with a carbon chain length of C-9 and a degree of oxyethylation of 6 is used as a surfactant, while the ratio of the rims of the invert emulsion and the emulsion polymer is 1: (from 5 to 6).

EFFECT: efficiency of the method for developing an oil reservoir heterogeneous in permeability is increased by increasing the coverage of the reservoir by the stimulation by creating filtration resistance by pumping an invert emulsion and increasing the oil displacement efficiency by involving low-permeability oil-saturated previously untreated zones of the reservoir by pumping an emulsion polymer slug into the development.

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