DEVELOPMENT METHOD OF HYDROCARBON DEPOSITS Russian patent published in 2015 - IPC E21B43/16 

FIELD: oil and gas industry.

SUBSTANCE: according to the method intervals of a well are completed opposite the gas-saturated part, so called gas cap, and oil-saturated part of a productive stratum. A tubing string is run in to the well. The gas cap is isolated by a packer. Gas is injected to the gas-saturated part of the productive stratum and the product is extracted by a borehole pump. Simulated completion opposite the gas-saturated part of the productive stratum is ensured by the creation of drainage channels oriented radially inward the stratum. Then two coaxially mounted tubing strings of a different diameter are run in to the well. The tubing string with a lesser diameter is run in to the level of the oil-saturated part of the stratum and equipped with the borehole pump connected by an exhaust line to the ground separator intended for the separation of associated gas. The tubing string with a bigger diameter is run in to the level of the gas-saturated part of the stratum and connected to a pressure line of the separated associated gas from the ground gas compressor. Oil is extracted through the tubing string of a lesser diameter. Injection of the separated gas is made through the tubing string of a bigger diameter. At that the separated gas under pressure is delivered to a space between packers in the gas-saturated part of the stratum over gas-oil contact (GOC) thus supporting energy of the stratum at a permanent level. As far as to oil extraction from the oil-saturated part of the stratum and injection of the separated gas to the gas-saturated part of the stratum, GOC boundary is shifted stage by stage as per the thickness of the stratum from its roof to the bottom thus ensuring the gradual oil draw-down rate.

EFFECT: reduced labour costs at implementing associated gas injection to oil wells in order to maintain the reservoir pressure during operation of hydrocarbon deposits and improvement of their productivity.

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