INDEPENDENT DRILLING SYSTEM FOR DRAIN WELLS Russian patent published in 2012 - IPC E21B7/04 E21B43/11 

FIELD: oil and gas industry.

SUBSTANCE: drilling system of drain well sideways from well shaft includes drilling bit containing drilling tool of drain wells and self-propelled device adapted for movement of bit in drain well during drilling, relay block lowered to the well shaft and prepared for positioning of drilling bit opposite side wall of well shaft so that drilling process of drain well can be initiated, electric current supply cable to drilling bit, which is uncoiled from relay block, and mechanical system for removal of drilling slurry from drain well during drilling process. Relay block is lowered to the well shaft. At least one drain well is drilled sideways from the well shaft with drilling bit receiving the electric power through the electric current supply cable uncoiled from relay block. Drilling slurry is removed from drain well during drilling with mechanical system; at that, removed rock debris fall to the bottom of well. Oil or gas is extracted from natural reservoir through drain well and well shaft.

EFFECT: enlarging the exchange surface between natural reservoir and well.

15 cl, 9 dwg