DEVICE FOR MAKING PERFORATION CHANNELS IN CASING STRING Russian patent published in 1996 - IPC

FIELD: well drilling and operation, particular, well perforation. SUBSTANCE: device for making perforation channels in casing string has hollow body with side channels. Cylinder with shoes is arranged outside of the body and forms hydraulic chamber together with body. Hydraulic chamber accommodates piston. Device also has cone (connected with body), cutters and valve. Connected with shoe is pusher. It is engageable with valve shutoff member. There are wedges with through longitudinal recesses, against which cone with blind recesses is made. Cutters are spring-loaded relative to the shoe and have shanks and cutter holder. They are connected with wedges for motion relative to each other. EFFECT: simplified technology of casing string perforation. 4 dwg