METHOD FOR CONSTRUCTION OF MULTI-HOLE WELL IN UNSTABLE RESERVOIRS Russian patent published in 2024 - IPC E21B7/06 

FIELD: mining.

SUBSTANCE: invention relates to methods of well completion in complicated conditions. Method includes drilling a horizontal shaft in the formation, lowering a casing string into it for securing unstable rocks of the formation, lowering into the casing of a coiled tubing pipe with a wire line, a deflector and a hydraulic monitor containing working and jet nozzles, a logging device, inclinometer and hydraulic monitor trajectory control unit, arrangement of annular space, tripping operations in well by coil tubing with deflector and hydraulic monitor, hydraulic monitor performs sidetracking, drilling and treatment of offshoots with washing with process agent through coiled tubing, and real-time use of logging tool, inclinometer and hydraulic monitor trajectory control unit during drilling of offshoots. Swellable pear-shaped packers are included in the casing string at a certain interval during its lowering, which are used for additional fixation of unstable formation rocks at the level of these packers. Said packers contain holes for sidetracking, which are arranged along one generatrix in the expanded part of the packers and oriented once during the casing string lowering taking into account the formation structure. Each hole is provided with a mark in the form of a section of discontinuity of the ring of a permanent magnet installed in the packer. Simultaneously with drilling of the offshoot, it is processed in a pulsed mode. Hydraulic monitor used is a repression-pulse hydraulic monitor with the possibility of its entry into the holes of the packers after their swelling in the well. Hydraulic monitor comprises inflatable packer located between working and jet nozzles, valve motor with pump and control unit for activation of inflatable packer, generation of hydraulic pulses and control of hydraulic monitor trajectory during drilling in specified direction. Hydraulic monitor is connected through bellows to coiled tubing pipe, which is made as combined – larger diameter in upper part of well and smaller diameter in lower part of well and its offshoots. Deflector is lowered at the end of the coiled tubing pipe of a smaller diameter and is used for selective entry by this pipe with a hydraulic monitor into the holes of the swelling packers with the possibility of subsequent kick-off through them, directional drilling, sidetracking, as well as installation of liners in a single cycle from one position of the deflector in the well. Deflector is made with possibility of its rotation, positioning and placement in the well at the level of any selected hole swelling packers, for this purpose the deflector is equipped with a unit of electric energy transfer to it, a control unit, an electric lock, an electric motor, a receiver of a magnetic mark, as well as a retractable centraliser and a ram retainer.

EFFECT: enabling the possibility of construction of a multi-hole well from a horizontal cased hole in an unstable section and weakly cemented reservoirs, improvement hydraulic monitor trajectory control, increased efficiency of drilling, sidetracking and well production.

1 cl, 10 dwg