METHOD FOR ISOLATION OF BRINE WATER INFLOW Russian patent published in 1998 - IPC

FIELD: oil and gas production industry. SUBSTANCE: method for isolation of brine water inflow to injection and producing wells implies injection of water solution or water suspension containing 1-30 mass% of salt of polybasic acid or mixture of salts of polybasic acids made with water containing up to 20 g/l of calcium and magnesium salts, and subsequent injection of water solution of alkali-earth metal and monobasic acid. Content ratio of polybasic acid salt of mixture of salts of plybasic acids and salt of alkali-earth metal and monoacid salt is selected within 1:(0.1-1). Used as polybasic acid salt are primarily sulfates, carbonates, silicates of metals, and used as salt of alkali-earth metal and monobasic acid are chlorides of magnesium, calcium, barium. Method is realized by injection into oil bed of solution or suspension of polybasic acid salt or mixture of salts of polybasic acids in water with subsequent injection of buffer water, which is followed by injection of solution of alkali-earth metal salt and monobasic acid. Then, well is started for operation. EFFECT: higher efficiency. 2 cl, 1 tbl