METHOD FOR DEVELOPMENT OF OIL DEPOSIT AT LATE STAGE OF OPERATION Russian patent published in 1999 - IPC

FIELD: oil production industry. SUBSTANCE: method is aimed at increasing oil recovery from beds and reducing flooding of producing wells. According to method, successively injected through injection wells is isolating Material which ensures levelling of injectivity profile, also injected is forcing-out agent. Prior to injection operations, collecting properties of beds are revealed in section of deposit. Used for isolation of high-permeable zones are polymer-dispersive systems. Used for fissured reservoirs are gel-forming compounds which fully plug fissures and prevent passing of forcing-out agent. Used for reservoirs of low or medium permeability are solutions of inorganic salts and alkalis which create settlements in result of their interaction. Forcing-out agent has viscosity which exceeds viscosity of oil in bed conditions and its interphase tension is not over 2.5 mN/m. Forcing-out agent is injected in amount of 20-30 thousand cub.m from combined pumping station. Application of aforesaid method ensures reduction of water recovery together with increasing coefficient of oil recovery from deposit. EFFECT: higher efficiency. 2 cl