DEVICE FOR WELL HYDRAULIC PERFORATION Russian patent published in 1995 - IPC

FIELD: construction; well development, operation and repair. SUBSTANCE: device for well hydraulic perforation includes hollow body with side holes to receive hard alloy nozzles. There is centralizer of hydraulic action which is made in form of extensible member. Made in body lower part is landing seat in form of ball for shutoff member. Piston is located in body hollow above centralizer. Piston is spring-loaded relative to body. Filter is blind and located above piston. Body hollow under piston is covered by plug to form chamber. Chamber is filled with oil. Nozzles are made in form of pipes with tangential inlets. They are spring-loaded relative to body and located above piston. Extensible members of centralizer are located at different level. They are made in form of piston-rods spring-loaded relative to body. Their above piston space is hydraulically communicated with body hollow. Body is made with peripheral axial channels communicating body hollow above piston with its hollow under plug. Besides, device has shear bushing which is installed in body above nozzles. Body has circulating holes against bushing. EFFECT: higher reliability of device operation. 2 cl, 5 dwg