DEVICE FOR PERFORATION OF CASED WELL Russian patent published in 1999 - IPC

FIELD: oil production industry. SUBSTANCE: device is made in the form of cylindrical body with central passage, circular groove, bypass passage, whipstock, and radial passages. Inserted atop into central passage is bush with external cone, piston and side passage. Hydraulic cylinder with piston, wedge-type slips interacting with external cone installed outside of bush create mechanism for locking in well. Located in lower part of body is mechanism for cutting out window in casing string. This mechanism has end milling cutter or drill bit, two pairs of gears, spindle, screw for axial feed of end milling cutter, shaft, hydraulic motor, and reverser. Located in body in area of window cutting mechanism is thrust mechanism with hydraulic cylinder, piston, wedge, and radial stops. Mechanism for extension of flexible hose with hydraulic giant nozzle through cut out window beyond limits of casing string into deposit bed has body which contains hydraulic cylinder, piston on hollow rod with radial holes. Arranged in body is mechanism for its axial movement with hydraulic cylinder and piston. Piston stroke, distance between axes of end milling cutter and nozzle and distance from lower end-face of bush to circular groove are made similar. Distance between radial holes and radial passages are made to be equal to piston stroke. Delivery of hydraulic working fluid at pressure of one of three values into each hydraulic cylinder and hydraulic motor is effected through hydraulic system with cut-off valve and control valves with respectively regulated springs. Hydraulic system ensures autonomous and automatic operation of each mechanism together with sending signal to ground surface through fluid delivery line about finishing of each operation, with return of mechanism to initial position. Application of aforesaid embodiment of device gives reliable and convenient functioning, reduction of power and cost inputs, longer service life together with intact of cement stone in hole clearance. EFFECT: higher efficiency. 2 dwg