METHOD FOR DEVELOPMENT OF OIL DEPOSITS Russian patent published in 1997 - IPC

FIELD: production of oil from wells. SUBSTANCE: method allows for increase of oil production from reservoirs due to enlarged embracing of collector by displacing agents. Drilling-over of oil deposit is started with most elevated part, and initially drilled wells are operated at low bottom-hole pressures so as to create degassing zone around them. Then, new rows of wells are drilled, with starting gas injection into initially drilled wells. Operation of producing wells is continued until extreme gas factor is achieved. For higher operating efficiency, at first stage, injected into reservoir is beneficated gas in amount of 1 to 40% of volume of pores of oil-saturated part of deposit with subsequent pushing of created fringe of beneficated gas by dry gas. At second stage, beneficated gas is injected in amount of 1.0 to 40% of volume of pores of entire deposit, then dry gas is injected. Wells which are drilled at second stage are operated at bottom-hole pressures which exclude degassing of oil in entire volume of reservoir. At second stage, gas and water are injected into reservoir alternately. EFFECT: high efficiency. 4 cl, 2 dwg