METHOD OF DEVELOPMENT OF NONUNIFORM PERMEABLE FORMATIONS Russian patent published in 2003 - IPC

FIELD: oil producing industry. SUBSTANCE: method includes alternating injection into producing formation between fringes of displacement fluid of suspension of water-soluble polymer in inert fluid carrier and aqueous solution with pH below 5.0 or above 8.0. Suspension of water-soluble polymer in inert fluid carrier additionally contains substances crystallizing in aqueous medium in amount of 0.5-50 wt.p.p. per 100 vol.p.p. of suspension. Displacement fluid is used in form of alcohols, glycols, ethers and other fluids preventing contact of isolating composition with aqueous solution and formation water in wellbore. Inert fluid carrier is used in form of pure oil, gasoline, gas-oil, hexane, diesel fuel, distillate, kerosene, condensate, natural bitumen or compositions on their base. Substances crystallizing in aqueous medium are used in form of cement or cement-limestone mixture. EFFECT: higher efficiency of development of nonuniform permeable formations due to increased reliability of isolation of water-encroached interlayers. 4 cl, 2 tbl, 2 ex