METHOD OF DEVELOPING WATER-FLOODED OIL POOL Russian patent published in 1998 - IPC

FIELD: oil-producing industry. SUBSTANCE: method includes injection into formation through at least one injection well and/or producing well of aqueous solution of salt of polyvalent metal and alkali solution with subsequent injection of working medium and oil is withdrawn through producing wells. Injected between injection of aqueous solution of polyvalent metal salt and alkali solution is displacement fluid. Aqueous solution of salt of polyvalent metal and/or displacement fluid, and/or alkali solution contain additionally water-soluble polymer. Alkali solution is used in the form of solution of alkali or salt solutions forming low-soluble compounds with salts of polyvalent metal or compounds containing them including production wastes. Polyvalent metal salts are used in the form of their technical grades or in the form of compositions containing them including production wastes. Displacement fluid is used in the form of working medium applicable of oil pool, and/or fresh water, and/or mineralized water. EFFECT: increased efficiency. 3 cl