OIL RESERVOIR DEVELOPMENT METHOD Russian patent published in 2024 - IPC E21B43/22 E21B43/30 

FIELD: oil industry.

SUBSTANCE: invention relates to oil industry and can be used in development of oil deposit with different type of reservoir. Disclosed is a method for development of an oil formation, characterized by that the main horizontal shaft of a branched well is drilled in the middle of a productive carbonate reservoir. Then, from the main horizontal shaft, branched shafts are drilled at an angle of not less than 60–65° from the main shaft towards the roof and bottom of the reservoir, wherein length of branching shafts to roof and to bottom of the reservoir makes at least 1.5 of thickness of productive reservoir while distance between bores of branching shafts makes 50–70 m. Further, 12–15% aqueous solution of hydrochloric acid is pumped into the main horizontal shaft of the well and branching shafts using a displacement fluid for 6 days at pressure of 1.5 MPa. Then, for 2 days, the hydrochloric acid solution is pushed deeper into the formation by displacement fluid – salt water, after which pumping is interrupted and stopped for holding for 5 days. Further, oil withdrawal is started and at reduction of oil flow rate of horizontal well with branches by 50%, the second cycle of acid treatment is performed.

EFFECT: increased oil recovery due to larger drainage coverage and treatment of bottomhole formation zone.

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