HYDROMECHANICAL SLOTTING PERFORATOR Russian patent published in 2003 - IPC

FIELD: oil producing industry; applicable in perforation of producing formations. SUBSTANCE: hydromechanical slotting perforator consists of body, two spring-loaded pistons with seals and cutting unit. One of pistons is integral in one unit with cantilever which has washing channel. Pistons are separated by gland with seals and interconnected by hollow rod. Hollow rod lower part has hole for fluid circulation through jet nozzle located on cantilever. Cutting unit includes extensible rolling roller connected with cantilever by means of crank carrying roller axle. Device has sliding support made as a part of cylinder. Its axis is parallel to axis of perforator and its diameter is equal to inner diameter of casing. Support is integrated in one unit with deflecting wedge located in its lower part. Wedge consists of two planes with hard-alloy inserts inclined to perforator axis, inserts come in contact with cranks having circular seals and located on both sides of rolling roller. Recess for motion of rolling roller is provided between planes. Upper part of sliding support is integrated with additional support for cantilever which has hole combined in transportation position with cantilever washing channel. Upper and lower parts of sliding support have bosses for its fastening in body with help of upper and lower inserts tightened by one lower nut. Upper insert has recess for accommodation of cantilever. Body lower part has rectangular through hole with walls parallel to perforator axis. Installed in said hole is sliding support with cranks and rolling roller. For return rolling roller to initial position, installed on both sides of sliding support are two plates with recesses parallel to planes of deflecting wedge. Located in recesses are projections of rolling roller. Pistons and gland have circular recesses for location of anticorrosive lubricant. They are located between seals. Recess lower face of pistons is made in form of truncated cone with small base upward, and in gland, with lower base downward. Hollow rod lower part is made in form of filter with diameter of holes smaller than diameter of jet nozzle. Upper part of perforator body has holes located in same plane. They communicate its internal and external spaces and are closed in transportation position by piston. Piston is locked relative to body by shear member located in one of holes. Piston upper seal is located above holes in perforator body, and piston lower seal is located under holes in body of this piston. EFFECT: extended technological potentialities of perforator and increased its service life. 6 dwg