BOREHOLE PERFORATOR Russian patent published in 2005 - IPC

FIELD: oil production industry, particularly well building and repairing and for creating perforation channels in casing pipes.

SUBSTANCE: perforator comprises body including wedge with grooves, cylinder filled with liquid and having piston and low-pressure chamber, which are arranged in series above the wedge, as well as supports having upper radial grooves. Cutters are installed in wedge grooves and in radial grooves of the support to provide synchronous displacement thereof. Cylinder part arranged under the piston cooperates with inner well space. Cylinder part located above the piston cooperates with low-pressure chamber through valve. Body between the wedge and cylinder is provided with additional cylinder with additional piston, which is rigidly connected with cylinder piston from above and with rod from below. Perforator comprises additional cylinder. Additional cylinder part located above piston communicates with that of the cylinder. Additional cylinder part located below piston communicated with well interior. Provided on outer part of low-pressure chamber are guiding means and bush displaceable in axial direction and having spring centrators and pin cooperating with the guiding means. Outer part of low-pressure chamber has limiter, which supports valve from outside when valve is installed in transport position. Limiter has inner cylindrical recess arranged in front of the valve in working position. Low-pressure chamber additionally is provided with release valve arranged from top thereof and fixed with shear screw. Release valve top is connected to rope, low part thereof has rest. Guiding means is made as a number of short axial grooves and one long axial groove connected by channels so that when bush reciprocates relative low-pressure chamber pin moves in series from one short axial groove to another one towards long axial groove, in which the pin is arranged in its working position. Bush and limiter may cooperate one with another in working position.

EFFECT: simplified structure and production.

3 dwg