METHOD FOR DEVELOPMENT OF OIL FRINGE OF OIL-AND-GAS DEPOSIT OF BOTTOM TYPE Russian patent published in 2020 - IPC E21B43/22 C09K8/592 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil industry and, in particular, to development of reserves of hard-to-recover oil of oil-and-gas deposits of bottom type with large area of oil-gas contact. Injection and production wells are drilled by the method. Then, the wells are perforated in the oil fringe localization interval. Thereafter, pores of hydrocarbon solvent are pumped into thickness of oil formation through injection wells in amount of 0.02–0.05 of pore volume and with viscosity of not more than 5 mPa·s. Then, a stabilizing rim is pumped based on a water-soluble polymer providing a resistance factor of not less than 10 and not more than 100, in an amount equal to half the volume of the fringe of the solvent. After that, at stabilized pressure there performed is pumping of displacing agent in form of preliminary prepared water-gas mixture with volume ratio of water and gas providing value of density of water-gas mixture in range of 80–120 % of density of oil in reservoir conditions. Simultaneously, oil is extracted until gas breaks into production well.

EFFECT: increased degree of oil displacement due to increased injectivity of wells and stabilization of front of oil displacement at their combined action.

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