RU2282013C1 - Jet pipe cutter - Google Patents

Abstract

FIELD: mining, particularly devices for longitudinal cutting pipes lowered in well.

SUBSTANCE: jet pipe cutter comprises strong sealed body with tip and head, elongated hollow-charge shell with blasting means and pressing means. Head is connected with pressing means by two screws spaced apart in height direction. The connection between elongated hollow-charge shell and head is secured by means of stop screw screwed into shell cavities. Device is provided with flat spring. Flat spring and stop screw are arranged from opposite longitudinal cutter axis sides.

EFFECT: increased efficiency and reliability.

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Description

The invention relates to the field of mining and specifically to devices for creating a longitudinal cut in pipes lowered into the well, for example, with the aim of releasing stuck pipes.

A known design of a cumulative pipe cutter containing a robust sealed housing with a tip and a head, an elongated cumulative charge with an explosive and a clamp device / 1 /.

A disadvantage of the known design is:

- insufficient reliability of the device for clamping the pipe cutter body to the pipe wall with the help of permanent magnets placed close enough to the area of the explosion of the charge, which leads to their demagnetization or even destruction and inability to reuse;

- in the prospectus / 2 / the known design is given in more detail. To orient the cumulative jet towards the clamp of the pipe cutter body against the pipe wall, the cumulative charge is fixed by a rod fixed in the head and tip in a given direction. This rod is placed inside the cumulative recess of the charge and passes along the entire length of the charge. The need for such a rod is caused by the fact that the charge is composed of individual short elements. However, the location of the rod in the cumulative recess reduces the charge efficiency.

The technical result of the invention is to increase the efficiency and reliability of the cumulative pipe cutter by connecting the head to the clamp device using two screws spaced apart in height, as well as by fixing the elongated cumulative charge with the head with a locking screw screwed into the cumulative recess of the charge, and the clamp device is equipped with a tape spring while the tape spring and the locking screw are located on opposite sides from the longitudinal axis of the pipe cutter.

The required result is achieved by the fact that in the known cumulative pipe cutter containing a robust sealed housing with a tip and a head, an elongated cumulative charge with an explosive device and a clamp device, the head is connected to the clamp device using two screws spaced apart in height, the elongated cumulative charge is connected to the head is fixed by a locking screw screwed into the cumulative recess of the charge, and the clamping device is equipped with a tape spring, while the tape spring and the locking screw m located at opposite sides of the longitudinal axis of the cutter.

The device of the proposed cumulative pipe cutter is shown in the drawing. The cumulative pipe cutter contains a robust sealed housing 1, a head 2 and a tip 3. An elongated cumulative charge 4 with a cumulative recess and blasting means 5 are placed in the housing. The tightness of the housing is ensured by O-rings 6 and a sealed electric lead 7. The pipe cutter is lowered into the well on a cable 8 connected to the locator of the pipe couplings 9. Between the body and the locator there is a clamping device 10, which is connected to the pipe cutter body using two screws spaced apart in height 11. The clamping device ma is provided with a longitudinal trough to accommodate a cable center conductor (CFA's) 12 and a spring strip 13. Fastening clamp the latter to a device carried by screws 14. The clamp apparatus is provided with additional fastening holes 15, allowing the spring to adjust the belt to the actual inside diameter of the pipe. The connection of the elongated cumulative charge 4 with the head 2 is fixed by a locking screw 16, screwed into the cumulative recess of the charge.

Cumulative pipe cutter works as follows. When descending into the well, due to the tape spring and gravity, the pipe cutter body is always pressed against the pipe wall, while the cumulative recess of the charge is directed to the place on the pipe inner wall, through which the pipe cutter body is currently in contact with the pipe wall. At a given depth with the help of a locator pipe couplings carry out the installation of an elongated cumulative charge against the selected coupling pipe connection. An electric current pulse undermines an explosive device, the detonation from which is transmitted to an elongated cumulative charge with a cumulative notch. When the elongated cumulative charge is triggered, a cumulative jet is formed, which, when it moves, first cuts the wall of the pipe cutter body, and then carries out a longitudinal cut of the pipe coupling, against which it was installed before undermining. The locator of the pipe couplings and the clamp device when lifting the cable are removed to the surface and used repeatedly. The cut coupling loses its strength, partially expands, and when the pipes are tensioned at the wellhead, their lower end leaves the coupling. Released pipes are removed to the surface.

The proposed cumulative pipe cutter can also be used to create a longitudinal gap in the pipes in order to restore circulation, to receive communication with the reservoir, etc. This design eliminates the accidental installation of the cumulative recess in a position different from the required, and the clamping device provides effective multiple use in pipes of various internal diameters.

Information sources

1. Patent US 5720344, 02.24.1998.

2. Prospectus of the company "Owen Oil Tool Inc", USA, 1998.

Claims (1)

A cumulative pipe cutter containing a robust sealed housing with a tip and a head, an elongated cumulative charge with an explosive and a clamp device, characterized in that the head is connected to the clamp device using two screws spaced apart in height, the elongated cumulative charge is connected to the head with a locking screw, screwed into the cumulative recess of the charge, and the clamping device is equipped with a tape spring, while the tape spring and the locking screw are located opposite to oron the longitudinal axis of the cutter.