ENHANCED OIL RECOVERY METHOD OF BED Russian patent published in 2020 - IPC E21B43/22 C09K8/584 

FIELD: oil, gas and coke-chemical industries.

SUBSTANCE: invention relates to oil industry, in particular, to methods of increasing oil recovery of reservoirs that are non-uniform as per permeability due to use of complex effect on deposit. In the method of increasing oil recovery of the formation, including carrying out a complex of hydrodynamic investigations and pumping through the injecting well into the oil-displacing polymer composition with different permeability, with preliminary pumping of water-insulating compound containing polyacrylamide and chrome acetate, which is ahead of rim is pumped 0.5–0.8 wt. % aqueous solution of surface-active complex composition - SCC, which is 0.04–0.07 wt. % by cationic surfactant in terms of active substance, and oil-expelling composition is an aqueous solution of polyacrylamide with additive of 1–3 wt. % SCC, which is a mixture of nonionic and cationic surfactants in an aqueous solution of low-molecular polyglycol.

EFFECT: technical result is higher efficiency of oil production due to increased coverage of formation by displacement, increased coefficient of oil displacement and directed action of cross-linked polymer systems on high-permeable interlayers of oil deposit.

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