METHOD OF DEVELOPMENT OF HARD-TO-RECOVER HYDROCARBON DEPOSITS Russian patent published in 2021 - IPC E21B43/24 E21B43/30 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil and gas industry and can be used for extraction of hard-to-recover hydrocarbons and, in particular, shale oil and petroleum shale oil, super-heavy oil and natural bitumen using thermal effect on productive formation. Method involves drilling and equipment of a well cluster. Columns of heat-insulated tubing string are installed in wells and packers are installed. Hydrocarbon oil production is performed. Production is performed cyclically. Each of the cycles includes several sequentially executed stages. Heat carrier is pumped via tubing string to borehole environment of productive formation. Wells are shut-off and maintained in closed state for heating with heat carrier in borehole zone. Then oil products are extracted to day surface. At that on the day surface there are modules for oil production. Each of these modules includes two well clusters and equipment for heat carrier generation and its pumping into borehole wells. Each bush comprises three wells arranged in a row. One of the wells is drilled vertically. Two other wells are drilled inclined and so that well faces are located in productive formation in rows. Heat carrier used is fluid with temperature 600–650 °C generated from water, which for each well is pumped into borehole environment of productive formation under pressure exceeding hydrostatic pressure of well. Injection is performed till formation of borehole retort in productive formation. After that, pumping stage is stopped. Selection of oil products of each well is carried out after the stage of holding and is performed in well flowing mode. At the hydrocarbons extraction stage of each cycle in-situ pressure is controlled. As soon as this pressure drops to preset value higher than hydrostatic pressure, extraction is stopped. Oil production cycles at each well are repeated several times, increasing retort sizes with each cycle due to action of heat carrier. After connection of retort with each other mode of cyclic extraction of oil products is terminated and mode of continuous extraction is performed. One of the wells of the cluster of each module is used as an injection well. Heat carrier is injected into pay to this reservoir. Two other wells of the bush are used as production wells, through which oil products are extracted in the well flowing mode.

EFFECT: higher production efficiency.

4 cl, 10 dwg