BOREHOLE PERFORATOR Russian patent published in 2005 - IPC

FIELD: oil production industry, particularly well forming and repairing, namely to create perforation channels in casing pipe.

SUBSTANCE: perforator comprises body with chamber formed as wedge with grooves and connected to cable from top thereof. Device has cylinder with piston arranged so that cylinder part located under piston communicates with well interior and cylinder part located above the piston communicates with body chamber located above the cylinder. Perforator also has support with radial grooves and cutters. The cutters may be inserted in wedge grooves and in radial grooves of the support. Chamber is composite and includes upper and lower parts concentrically connected one to another so that upper and lower parts may be displaced in axial direction in air-tight manner one towards another. Outer surface of lower chamber part additionally has self-sealing collar providing flow in bottom-top direction. Upper chamber part communicates with well interior and is additionally provided with pusher having conical surface. In working position conical pusher surface presses self-sealing collar to well walls. Upper support part is provided with inner cylindrical depression for wedge insertion and is made of conical part, cylindrical part and rest arranged one after another in top-bottom direction. Support additionally has anchoring unit located on cylindrical part thereof and may be displaced in axial direction. Anchoring unit comprises rigid centrators with guiding pin and dies spring-loaded inwards. In working position dies may cooperate with conical support part. Outer surface of cylindrical support part has grooves cooperating with guiding pin. The grooves include a number of short axial grooves and one long axial groove connected by channel so that when anchor unit reciprocates relative support guiding pin passes in turns in long and short axial groove parts.

EFFECT: increased reliability and efficiency.

3 dwg