CASED WELL PERFORATION SYSTEM Russian patent published in 2019 - IPC E21B43/112 

FIELD: soil or rock drilling.

SUBSTANCE: invention relates to drilling equipment, in particular, to means of producing liquid or gaseous fluids from boreholes, and can be used in well penetration of deep penetrating perforation of primary or repeated opening of productive formations. System for perforation of cased wells includes tubing string, clamping device, anchor, suspension in form of logging cable, screw downhole motor, flexible shaft with cutting tool at end. Piston is arranged in damping device, which is located between screw-like face motor and flexible shaft. Damping device is made in the form of tube of square cross-section. Piston is also square-shaped and is connected with flexible shaft. Housing of screw downhole motor is fixed in pipe string by means of key assembly, at that output shaft of screw downhole motor is connected to damping device with possibility of transfer of torque and axial force to flexible shaft and cutting tool. Screwed downhole motor in end part is equipped with adapter, which is installed in thrust coupling of engine mounting connected with damping device. Adapter in its central part is made with through hole for shaft of screw-down engine.

EFFECT: stable accident-free casing drilling mode and preset depth of productive formation opening, smooth feed of the tool, as well as reduced time consumption.

1 cl, 1 dwg