OIL DEPOSIT DEVELOPMENT METHOD Russian patent published in 2013 - IPC E21B43/20 

FIELD: oil and gas industry.

SUBSTANCE: method involves delivery of water-gas mixture to oil deposit through an injection well; the mixture is prepared at the mouth of the injection well by means of a mixer and then delivered to the mixer under pressure of water and gas. According to the invention before delivery of gas stream light hydrocarbon fractions, foe example, oil, gas condensate, associated gas or a mixture of low-pressure gas with fractions of hydrocarbons C_2+higher are input into the mixer by means of an ejector. At that mixing of high-pressure gas with a stream of gas having high concentration of hydrocarbon fractions C_2+higher is carried out by means of an ejector installed in the gas well in production tubing over the roof of high-pressure gas formation. The stream of gas from high-pressure gas formation in drill string - borehole annulus is isolated by means of an isolating packer from the stream of low-pressure gas and delivered to high-pressure nozzle of the ejector. At that the stream of low-pressure gas with high content of C_2+higher fractions fed from the well mouth through borehole-drill string annulus of the gas well is sent to low-pressure chamber of this ejector.

EFFECT: improvement of oil recovery factor with simultaneous prevention of low-pressure gas compression using compressors or similar power plants.

4 cl, 1 dwg