METHOD OF DEVELOPMENT OF OIL POOL Russian patent published in 1999 - IPC

FIELD: oil production. SUBSTANCE: method includes maintaining of formation pressure by injection into formation of displacement agent. For this purpose, subject to determination on section of oil pool are oil withdrawal volume of injected displacement agent and time for observation of the process, and efficiency of process of maintaining of formation pressure and its effect on formation. Technology of maintaining of formation pressure is varied. Displacement agent in varied technology of maintaining of formation pressure is used in form of CO₂ margin generated in formation and forced over formation with water. In this case, CO₂ margin is produced in formation by successive injection of aqueous solution of neutral salt of carbonic acid with addition of 0.5-1 wt.% of surfactant, 0.05-0.2 wt.% of water-soluble polymer of acryl series, and acid solution. Efficiency of maintaining of formation pressure and its effect on formation are assessed by Herst's index determined in course of process. Technology of maintaining of formation pressure is varied with Herst's index amounting to less than 0.5. EFFECT: higher efficiency of system f maintaining of formation pressure and oil recovery from formation. 3 cl, 2 tbl