SYSTEM AND METHOD OF DRILLING A PILOT HOLE THROUGH A WELL WALL Russian patent published in 2019 - IPC E21B43/11 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil and gas industry and is intended for perforation of walls of cased and uncased wells and opening of productive formations. Drilling system comprises a hollow tube, on one side connected to the engine, and on the other side with a leaf flexible shaft. Flexible shaft is connected to the bit body. Fluid medium hose passes through hollow tube, flap flexible shaft and bit body. Fluid hose is equipped with compensating piston arranged in hollow tube channel and sealing piston arranged in channel of bit case. Compensating piston has bypass channels for fluid medium, intended for compensation of pressure in hose at compression of flexible shaft. Proposed method comprises lowering drilling system and locking system in borehole in preset interval. System is directed by means of a diverting device to the drilling point in the well shaft wall. Channel is drilled by bit to feed fluid through hose.

EFFECT: perforation of casing strings and well shaft, extension of artificially created permeability channels and increased extraction of formation medium.

19 cl, 4 dwg