METHOD OF DEVELOPING LOW-PERMEABLE OIL DEPOSIT USING SEPARATE INJECTION OF WATER AND GAS Russian patent published in 2020 - IPC E21B43/20 

FIELD: oil, gas and coke-chemical industries.

SUBSTANCE: invention relates to oil industry and can be used in development of low-permeability oil deposit with application of separate injection of water and gas. Method includes deactivation of the wells in conservation as production and injection wells, isolation of the productive stratum in the given wells, injection of working fluid into the injection wells with creation of vertical lateral displacement, extraction of products from production wells. According to the invention, the deposit with total oil-filled formation thickness of not less than 50 m is selected, at least one development element is selected, which is an injection well with production around, wells are selected so that the distance between the boreholes of the injection and production wells in the productive part of formation is 300–1000 m, for this, if necessary, vertical and/or directional wells are additionally drilled, after initial extraction of the formation product and reducing formation pressure to a level not lower than oil saturation pressure of gas, injection wells are started to conduct simultaneous separate injection of water and gas, perforating not more than 1/3 of the formation at the roof and not more than 1/3 of the formation at the foot, wherein the gas is pumped to the roofing part of the formation, and the water is poured into the bottom part of the formation, the product is withdrawn from the production wells, and respectively, and the perforation is performed in the middle part of the productive formation, not more than 1/3 of the thickness, wherein the number of injection wells, ratio and type of water and gas are determined from results of laboratory studies on oil displacement and hydrodynamic simulation with volumes of water and gas, available for pumping in the area of given deposit and with achievement of maximum oil recovery, in the process of development, monitoring of injection and withdrawal is performed by means of hydrodynamic simulation, working agent breakthrough to production wells, as well as prevention of reduction of formation pressure below oil saturation pressure by gas are controlled by modes and operating time of all wells of the deposit, periodically replacing pumping of working agents - pumping of gas is carried out in the bottom part of the formation, and water - in the roofing part of the formation.

EFFECT: higher oil recovery.

1 cl, 2 ex