METHOD FOR DEVELOPMENT OF OIL DEPOSIT Russian patent published in 1999 - IPC

FIELD: oil production industry. SUBSTANCE: method relates to development of oil deposits with lower oil-saturation of oil-bearing rock. According to method, drilled are producing and injection wells, gas and water are injected into injection wells, and oil is recovered from producing wells. Gas and water are injected in three stages. At first stage, gas is injected. At second stage, gas and water are injected by multiple alteration. At third stage, water is injected. At first stage, gas is being injected into each injection well until recovery of injected gas reaches amount of not less than 500 cu. m per 1 t of oil. At second stage, gas and water are injected into each injection well by multiple alteration. At each period, gas and water are injected in volume equal in bed conditions to 1-2% of initial geological reserves of oil in deposit section served by given well. Volumetric proportions of gas and water are correspondingly equal to 70-90% and 10-30%. Injection operation is carried out until recovery of injected gas from producing well reaches amount of not less than 500 cu.m per 1 t of oil. After that, injection of water is initiated at third stage. Application of aforesaid method ensures increase of oil recovery from beds. EFFECT: higher efficiency.