METHOD OF DEVELOPMENT OF OIL DEPOSIT Russian patent published in 1997 - IPC

FIELD: oil producing industry, in particular, development of oil deposits by injection in formation of displacing agents. SUBSTANCE: method includes injection of water and gas into injection wells and recovery of oil from producing wells. Displacing fluid is injected in form of water-gas mixture formed in ejection process. Volume of sucking-in gas is maintained at the level at which viscosity of formed water-gas mixture in formation conditions is equal to viscosity of formation oil. Upon reaching of producing wells by displacement front, aeration degree of water-gas mixture is increased by 2-5 times to reduce intake capacity by 1.5-2.5 times. Then, injection pressure is raised by 1.1-1.5 times to restore initial intake capacity. Added to injected water is mixture of two surfactants - anionic and nonionic types with concentration of 0.1-1% with their ratio of (1:1)-(1:3). EFFECT: increased efficiency of displacement. 2 cl, 7 tbl