HYDROMECHANICAL SLOT-TYPE PERFORATOR Russian patent published in 2015 - IPC E21B43/114 

FIELD: oil and gas industry.

SUBSTANCE: hydromechanical slot-type perforator includes pusher stem, cutting sections with retractable cutting discs, cutting disc retraction unit in the form of an arm with one side rotating on the arm axle mounted in the work stem while the other side with a cutting disc mounted on the axle engages with deflecting wedge attached in the work cylinder. A through longitudinal slot is made in the work cylinder opposite to the cutting disc. Cutting sections are installed in line, their work stems can travel axially in one direction when actuated by the pusher stem and in the opposite direction under effect of return spring. Supporting sections are installed in front of and behind the cutting sections, each supporting section is a hollow bushing with connection threads at ends and with central through orifice where a bushing pusher is installed so as to allow for axial travel, and ports are made in the side bushing surface along the diameter where rollers are mounted on axles.

EFFECT: reduced friction of reciprocal travel of perforator during slot cutting in casing column, improved reliability of perforator.

7 cl, 3 dwg