OIL POOL DEVELOPMENT METHOD Russian patent published in 2000 - IPC

FIELD: oil and gas production. SUBSTANCE: when developing oil pool in the late development phase, working agent is injected through injection wells and product is taken out of productive wells. At least one productive well is shut off. Initially perforated intervals are insulated. From the depth level above upper perforation interval, new slant borehole is drilled, which can pass into of horizontal hole within productive formation. Horizontal or slant hole is led through the upper boundary of productive formation to the half distance between working wells. New bottomhole is placed at distance not less than 100 m from initial bottomhole. When producing oil through well, formation depression no higher than 1 MPa is maintained. EFFECT: increased oil pool recovery.