PROCEDURE FOR UTILISATION OF LOW PRESSURE GAS Russian patent published in 2011 - IPC E21B43/00 E21B43/34 F04F5/54 

FIELD: oil and gas production.

SUBSTANCE: procedure for utilisation of low pressure gas in field consists in supply of low pressure oil gas from end separation unit ESU into ejector of "gas-liquid", whereat oil field drain water is used as working agent. Further, the procedure consists in compression of low-pressure oil gas in the said ejector and in production of water-gas mixture, in supply of produced water-gas mixture to a stage of purification of oil field drain water from oil, in separation of gas from oil field drain water and in utilisation of separated gas as a flotator, in supply of oil field drain water purified by flotation into a tank for further purification by the method of gravitation settling. Purified water is supplied to a cluster pump station to be pumped into a reservoir. Oil separated during flotation is supplied to the ESU. Separated gas as passive gas is directed to the ejector of "gas-gas" type, wherein high pressure gas is used as active gas. Passive gas is compressed to pressure sufficient for transporting it to a consumer together with high pressure gas.

EFFECT: reduced power expenditures and workload on separation stage of high pressure gas, increased efficiency of oil field drain water purification, utilisation of low pressure gas of separation and flotation stages.

4 tbl, 2 dwg