METHOD OF OIL RESERVOIR EXTRACTION (VERSIONS) Russian patent published in 2016 - IPC E21B43/22 C09K8/584 C09K8/588 

FIELD: oil industry.

SUBSTANCE: invention relates to oil industry, to methods of oil reservoir extraction, in particular. Method of oil reservoir extraction includes successive water solution of alkali with SAS and water solution of polymer pumping into reservoir through fringe injector well with subsequent flooding and oil extraction through production wells, water-soluble oxyethylated alkylphenol (WOA) is used as SAS, polymer is polyacrylamide (PAA), initial intake capacity of injection well at pumping pressure is measured at first, maximum allowable production string pressure is calculated, volume ratio of pumping fringes depending on initial intake capacity of injection well is measured, mineralization of pumped water is additionally specified and if its value is 0.15-45 g/l, first fringe is pumped in until pumping pressure is increased by 15-30 % of initial pumping pressure, mixture of aqueous solution of alkali with WOA and PAA is used as first fringe containing following proportions, wt %: alkali - 0.1-3.0, WOA - 0.05-0.3, PAA - 0.05-0.8, water with mineralization from 0.15 up to 45 g/l - the rest, second fringe is pumped in until pumping pressure is increased by 30-70 % of the initial pumping pressure to maximum allowable production string pressure, mixture of aqueous solution of PAA and PAA is used as second fringe containing following proportions, wt %: PAA - 0.05-0.8, WOA - 0.05-0.3, water with mineralization from 0.15 up to 45 g/l - the rest, volume ratio of fringes is 1:1 with intake capacity of 100-250 m³/day and (1-2):1 with intake capacity of 250-400 m³/day, and before pumping of mentioned fringes water solution of PAA with concentration of 0.05 to 0.5 wt % is pumped in volume equal to the first fringe volume or pumped amount of water with mineralization from 0.15 up to 45 g/l in amount of 10-20 m³. In another version of this method with mineralization of 45-300 g/l first fringe is pumped until pumping pressure is increased by 15-30% of the initial pumping pressure, mixture of aqueous solution of alkali with WOA is used as first fringe with their component ratio, wt %: alkali - 0.1-3.0, WOA-0.001-0.15, water with mineralization 45-300 g/l - the rest. mixture of aqueous solution of PAA and WOA is used as second fringe with their component ratio, wt %: PAA - 0.05-0.8, WOA - 0.05-0.3, water with mineralization 45-300 g/l - the rest, second fringe is pumped in until pumping pressure is increased by 30-70% of the initial pumping pressure to maximum allowable production string pressure, volume ratio of fringes is 1:(1-2) with intake capacity of 100-250 m³/day and 1:(1-3) with intake capacity of 250-400 m³/day, and before pumping of mentioned fringes water solution of PAA with concentration of 0.05 to 0.5 wt % is pumped in volume equal to the first fringe volume or pumped amount of water with mineralization from 45 up to 300 g/l in amount of 10-20 m³.

EFFECT: technical result is increase of efficiency of oil displacement from reservoir, reduced loss of SAS and alkali.

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