DOWNHOLE PIPE PUNCH Russian patent published in 2003 - IPC

FIELD: underground repair of oil, gas and other wells and also for communication of tubing and casing cavities with annular space for creation of circulation, injection of various reagents and solutions, equalizing pressure and other purposes. SUBSTANCE: downhole pipe punch is lowered into well on working string and has hollow body filled with fluid and having side channels communicating with body cavity. Installed in body side channel is piston with working member, and body is rigidly connected with hollow cylinder. Hollow cylinder accommodates rod for axial motion and piston connected with rod, which form rod and working chambers together with cylinder. Sub is rigidly connected to cylinder. Novelty consists in that working string is used in form of string with hydraulic channel for supply of force fluid as energy carrier from pump. Working string internal cavity is hydraulically connected with working chamber and well cavity through throttles made in sub. Rod chamber is communicated via hole in cylinder with well cavity and rod and piston are interconnected and spring-loaded for provision of rod position moved-out of body. Punch rod has inertial load for engagement with fluid contained in body. Installed in sub is slide valve communicating working chamber with well cavity. Slide valve locking member in closed position is fixed by means of pin broken by pressure action of force fluid. EFFECT: provided hole punching in well at any depth without use of rest and irrespective of weight of working string and higher reliability of device. 3 dwg