METHOD OF LEVELING THE INJECTIVITY PROFILE OF INJECTION WELLS Russian patent published in 2018 - IPC E21B43/22 C09K8/512 

FIELD: oil industry.

SUBSTANCE: invention relates to petroleum industry, in particular to the methods for leveling the injectivity profile of injection wells, and is aimed at increasing the oil recovery of deposits with carbonate and terrigenous reservoirs with an increased content of carbonates. In a method for leveling the injectivity profile of injection wells in carbonate and terrigenous reservoirs with an increased carbonate content, including injecting into the injection well an aqueous solution of a crosslinking polymer composition containing polyacrylamide with a molecular weight of 5 to 15 million and a degree of hydrolysis of 5-30% and chromium acetate, and extraction of oil through production wells, before injection of said solution, a solution margin of the aqueous solution of chromium acetate at a concentration not exceeding 0.1% in volume equal to the volume of said solution is pumped at a minimum speed, and after pumping of said solution, water is pumped to push it to the required depth and the well is left for the reaction to perform.

EFFECT: technical result is an increase in the leveling efficiency of the injectivity profile of injection wells due to the enhancement of the adhesion of the rock to the polymer and, accordingly, the increase in the residual resistance factor.

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