CASING PIPE PERFORATING MACHINE Russian patent published in 2010 - IPC E21B43/112 

FIELD: oil and gas production.

SUBSTANCE: casing pipe perforating machine comprises a tube and support housings, a cylinder connected to the support housing and comprising an actuating piston with a return spring and a slip pusher equipped with working cutters longitudinally movable in relation to the slip pusher when actuated by the support housing, a valve gear with its casing mounted above the cylinder, and a secondary return spring. The tube housing is connected to the piston to perform constrained longitudinal movement. The cylinder above the support housing is provided with a ring seat; the piston has a collar, and the return spring is mounted between the external collar of the piston and the ring seat of the cylinder. The tube housing has a seat above the ring collar of the piston, while the secondary return spring is mounted between the seat and the piston in the cylinder. The valve gear casing is rigidly connected to the tube housing and accommodates on its top a valve seat, and at the bottom - a leaky internal seat. The spring is applied to press the valve to the seat of the valve gear casing from the internal seat so that to hold a liquid column forcing the valve in the perforation range.

EFFECT: enhancement, production simplification and reduction in price, higher design reliability.

2 cl, 3 dwg