HYDRAULIC PERFORATOR Russian patent published in 2002 - IPC

FIELD: oil, gas and water extraction, perforation of wells. SUBSTANCE: perforator has body with cylinders and conduit, piston with hole coming in the form of conical or cylindrical sections with common axis. Piston is located in one cylinder with degree of freedom to move along and around own axis and limited axial movement. It is supported by butt and cylindrical bearings. Rotation axis crosses axis of hole in parallel planes at angle chosen on basis of assignment of number of revolutions of piston and maintenance of perforation potential of outgoing jet. Distance between points of crossing of these axes with internal surface of perforated column is equal to planned radius of perforation conduit. To limit axial movement of piston which maximum value is computed on condition of its non-power contact with internal surface of column during its maximum stroke internal butt of piston carries flange along which holes inside conical section of hole are drilled. External butt surface of piston comes in the form of part of sphere with conduits and recess in its butt around through cylindrical hole in piston and radius equal to radius of internal surface of column. Conical transitions to conduit supplying liquid are made inside body in front of piston. EFFECT: reduced perforation time. 1 cl, 4 dwg