DEPRESSION-REPRESSION DRILLING ASSEMBLY FOR COMPLETION AND REPAIR OF WELL Russian patent published in 2019 - IPC E21B37/00 E21B21/00 E21B43/26 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to drilling, cleaning, flushing, treatment, hydraulic fracturing, exploration and investigation of oil and gas producing wells. Assembly contains a single pipe string, a hydraulic motor with a spindle sealed by means of a seal, an output shaft, a near-dock adapter and a chisel, a hydraulic engine sub, two packers – upper and lower, an inter-packer port for pumping process liquid, jet pump fed with active medium by surface pump and including nozzle connected to active medium feed channel, diffuser with output to upper packer above-packer zone and mixing chamber connected with under-packer zone of upper and lower packer by channel of passive medium supply. Packers are made inflatable, hydraulic engine installed first in the direction of active medium supply, and jet pump installed by the second one, are hydraulically connected in series with possibility of all active medium direction after downhole motor into nozzle of jet pump. Spindle seal is made in the form of a rubber ring and two inflatable seals arranged second in the direction of medium leakage and interacting with the cavity of increased pressure of the jet pump. Lower hollow part of the output shaft contains a hole between two inflatable seals and connected by pass channel of passive medium supply to the mixing chamber. Inter-packer port in the spindle is connected to the active medium feed channel. Spindle comprises lower-packer opening-closing system, passive medium supply channel from under-packer zone of upper and lower packer and inter-packer port in form of four solenoid valves, control unit, pressure sensor and power supply unit controlled via hydraulic communication line. Upper packer is installed on bushing equipped with inflatable seal, which is put on outer smooth side of double pipe string, introduced between hydraulic engine sub and single pipe string with possibility of axial movement relative to bushing. Bushing is equipped with a system of opening-closing of the upper packer in the form of an oil electric pump, a control unit, a differential pressure sensor, a power supply unit and an electromechanical lock with a position sensor connected to the control unit, which is controlled via a hydraulic communication line. Hydraulic motor is equipped with an external channel connecting the diffuser of the jet pump through the external channel of the sub-adapter of the hydraulic engine with annular space of the double pipe string, having an outlet through the external channel of the introduced additional sub in the above-packer zone of the upper packer.

EFFECT: increased depression to the formation, increased reliability of operation in various well conditions, possibility of interval-by-interval action on the formation.

1 cl, 5 dwg