METHOD FOR DEVELOPMENT OF OIL FIELD Russian patent published in 1994 - IPC

FIELD: oil producing industry. SUBSTANCE: method consists in injection of aqueous solution of ammonium salt through injection wells, heating of ammonium salt solution in formation and oil recovery through producing wells. Ammonium salts are used in form of ammonium carbonate and ammonium nitrate. Aqueous solution of ammonium carbonate is injected in form of fringe amounting up to 0.2-0.4 of pore space, then, aqueous solution of mixture of ammonium nitrate and acid with pH 3 is injected in form of fringe amounting up to 0.1-0.4 of pore space and then, water is injected. Besides, injected between fringes of aqueous solution of ammonium carbonate and aqueous solution of mixture of ammonium nitrate and acid is water fringe amounting to 0.05-0.2 pore space. EFFECT: higher oil recovery. 2 cl, 1 tbl