METHOD FOR EXTRACTING DEEPLY IMMERSED HYDROCARBON FORMATIONS Russian patent published in 2007 - IPC E21B43/20 

FIELD: oil and gas extractive industry, possible use during extraction of deeply immersed oil-gas deposits of large volumes, having natural conditions allowing mixing of gas with formation oil.

SUBSTANCE: in accordance to method, deposits are drilled by product wells. Oil is extracted through aforementioned wells by fountain method until bed pressure is lowered below saturation pressure. Amount of hydrocarbon mass of deposit is determined in advance. It is divided by resources on two even shares (upper and lower). Each one of selected deposit shares are drilled by vertical and/or horizontal wells. Extraction is performed by realization of three main mode conditions. One of realization modes is resilient water-forcing mode with flow of resource of resilient energy of bed systems and liquids saturating them up to pressure at which oil is saturated with gas. Realized also is combined mode of filtration of fluids - oil, gas and water with gradual increase of coverage of oil-saturated collectors with diluted gas mode under conditions of bed pressure decrease for 50-90% below saturation pressure of saturation and intrusion of waters of water-forcing body. Realized additionally is deep development of diluted gas mode with influx of water from water-forcing body with three-phased filtration of bed fluids.

EFFECT: increased technological and economical efficiency of extraction of deeply immersed oil formations.

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