METHOD OF OIL DISPLACEMENT FROM FORMATION Russian patent published in 2001 - IPC

FIELD: oil producing industry, particularly, methods of oil displacement from formation by injection of physico-chemical substances. SUBSTANCE: method includes injection of water through annular space of injection well and gas through tubing. Formed on bottom hole is water-gas mixture by ejection. Oil is displaced toward producing wells. Ejecting device is installed on bottom hole of injection well and provided with check valve in point of gas introduction into ejecting device. Line of tubing string of injection well is connected with annular space of producing wells. Periodically added to injection well is surfactant with 0.5-1.1% concentration. After operation of check valve of ejecting device, formation is treated with solutions of acids forming water-soluble salts in content with carbonate rock skeleton. EFFECT: higher efficiency of method. 1 dwg, 1 tbl