An efficient tool for reconstruction of hydrodynamic connection between the tubing and casing clearance in the well by means of the stalks’ wall perforation while performing repairs or other technological activities.

PNKT perforator is indispensable at conducting repair works in the well; when lifting tubing (NKT) on the surface is connected with the risk of oil or the well’s fluid spill, in cases of piston break and impossibility to catch the cone in the wells equipped by plunger pumps (Sucker-Rod Pump).

Perforation necessity arises at damping of flowing well, when a blockage occurs or at emergency conditions when hydraulic disintegration of stratum (packer breakdown) takes place and also at the shut down of a well, equipped by electrical centrifugal pump, when it is impossible to “hit off” the valve .

The perforator is a hydraulic two-stage pressure transformer, in which, due to hydro-statistic liquid pressure in the drilling string, pressure increases for 16 times, which is enough for mechanical perforation of an orifice by the ramrod cone, at the designated point of the tubing wall.

The device is drawn down into the tubing string through the lubricator with a help of a hoist, which uses scratch wire, logging cable or, when there is a necessity, in loose condition.

The perforator snapping into action and assembling of its working constituents into starting position happen due to the action of hydro-static pressure of the spout in the tubing string, when the amount of this pressure is enough to shear stud.

Otherwise the perforator snapping into action takes place as a result of shearing the stud under the action of resultant pressure – overpressure at the wellhead and hydro-static pressure of the spout. All this helps the device to surface.