METHOD FOR INCREASING OIL RECOVERY OF RESERVOIR Russian patent published in 2023 - IPC E21B43/16 

FIELD: oil and gas industry.

SUBSTANCE: used to increase the rate of hydrocarbon recovery from reservoirs during surfactant-polymer flooding. The method for increasing oil recovery includes determining the injectivity of an injection well, preparing and pumping a mixture of surfactant with a polymer through the injection well, and withdrawing oil through production wells. At the same time, a section of an oil deposit is selected with a ratio of injection wells to production wells of 1:3-1:5. After that, oil is sampled through production wells to measure production rates, interfacial tension between oil and water, and water viscosity. Next, the arrival of the shaft of oil to one of the production wells is determined by the increase in production rates, a 2-fold decrease in the value of interfacial tension between oil and water, and an increase in 1.5 times the value of water viscosity. Then, after a decrease in the oil production rate from the maximum value by 12.5%, hydraulic fracturing is carried out in this production well. After the hydraulic fracturing of the reservoir, the production well is put into operation and the set of works is repeated on another production well that has responded to the injection of a mixture of surfactant with a polymer. The development is carried out before the development of a section of an oil deposit.

EFFECT: increased oil recovery of the formation is provided with simultaneous impact on production and injection wells due to hydraulic fracturing of the formation on production wells during the arrival of the oil shaft formed as a result of surfactant-polymer treatment.

1 cl, 1 dwg