RU100799U1 - Casing Repair Tool - Google Patents

Abstract

 1. A device for repairing a casing string in a well, comprising a drive with two expanding punches placed on one rod, and an expandable nozzle with a reduced inner diameter of the end sections, characterized in that the inner diameter of the end sections of the pipe is reduced by narrowing it without increasing the thickness moreover, the narrowed end sections of the pipe are pre-expanded at the ends to a length of at least two wall thicknesses of the pipe at its ends, and on the outside they are wearing elastic seals made e in the form of a thin-walled cylindrical shell and secured against movement with one end through the flange sleeve, wherein the upper punch set beneath the upper end portion at a distance sufficient to expand the lower end portion. ! 2. A device for repairing a casing string in a well according to claim 1, characterized in that for blocking long sections of the casing string, the pipe is made of several pipes connected to the wellhead by threading or welding.

Description

The utility model relates to the oil industry, in particular, to overhaul of wells.

A device for repairing a casing string is known, including an expandable pipe with a reduced inner diameter of the end sections due to their thickening inward (see USSR AS No. 1086118 publ. 15.04.84. Bull. No. 14).

Its disadvantage is the need to use large drive forces to expand the thickened end sections.

Closest in technical essence to the proposed device for repairing a casing string, including an expandable nozzle at the ends, the end sections of which having a wall thickness, like the whole nozzle, are narrowed with easily expandable inserts (see AS USSR No. 1153037 publ. 04/30/85. Bull. No. 16).

Its disadvantages are design complexity and low tightness due to the lack of a sealant.

The technical problems solved by the proposed device is to increase the tightness of the device and simplify its design.

This problem is solved by the proposed device for repairing the casing string in the well, including a drive with two expanding punches placed on one rod, and an expandable pipe with a reduced inner diameter of the end sections.

What is new is that the inner diameter of the end sections of the pipe was reduced by narrowing them without increasing the thickness, and the narrowed end sections of the pipe were previously expanded at the ends to a length of at least two pipe wall thicknesses at its ends, and elastic seals made of them in the form of a thin-walled cylindrical shell and secured against movement from one end on the collar of the pipe, the upper punch installed below the upper end portion at a distance sufficient for p Expansion of the lower end portion.

New is also the fact that for overlapping long sections of the casing string, the nozzle is made prefabricated from several pipes connected at the wellhead by thread or welding.

The figure shows a diagram of the device.

The device (see figure) contains a pipe 1 with lower 2 and upper 3 narrowed end sections, on which elastic seals 4 are mounted, fixed with the lower end on the shoulders 5. The narrowed sections 2 and 3 at the ends 6 and 7 are made expanded.

A rod 8 is placed inside the nozzle 1, connected to the lower punch 9 from the bottom, and to the upper 10, installed at a distance greater than the actuator stroke necessary to expand the lower end portion 2. There is a thread 11 on the upper end of the rod for attachment to the actuator (not shown in the figure).

The device operates as follows.

The device is lowered into the well on a string of tubing (tubing) together with a hydraulic drive (not shown in the figure) and installed so that the sealed section of the casing (not shown) is between the seals 4.

Then, liquid is supplied to the tubing string under pressure. Under the action of fluid pressure, the hydraulic drive pulls the rod 8 up together with the punches 9 and 10 mounted on it, while the pipe 1 abuts the upper end against the drive. Moving upward, the punch 9 expands the lower narrowed end portion 2, pressing the seal 4 against the walls of the casing. The upper punch 10 thus moves inside the pipe. Upon completion of the expansion of the lower section 2, the upper punch 10 reaches the upper end section 3 and expands it, pressing the seal 4 against the walls of the casing. After the upper punch 10 passes through the upper end portion 3, the pressure in the tubing is leveled and lifted from the well together with the hydraulic drive and rod 8 with the punches 9 and 10 installed on it.

In the borehole there remains a pipe 2 with seals 4 tightly pressed against the casing walls, cutting off the leaky casing interval from the borehole cavity.

Extensions 7 and 6 ensure the elimination of the end effect, which is expressed in the narrowing of the ends of the pipe 1 when it is expanded by the punches 9 and 10, and the protection of the seal 4 when the device is lowered into the well. The upper expansion 7 can also serve as the exit point for the upper punch or its thick part after the expansion of the upper section 3 is completed. In addition, the preliminary expansion of the ends of the narrowed sections also serves as a check of their integrity for the absence of internal defects that could lead to the formation of a crack during planting in the well , i.e. to the accident. The presence of elastic seals 4 ensures a tight pressing of the end sections 3 and 2 even in the presence of small scratches and shells on the inner surface of the casing. The shoulder 5 prevents the shift of the seals 4 when the device is lowered into the well.

The narrowed end sections 2 and 3 can be made directly on the pipe 1 or attached to it by welding or thread. If the sealing interval and, accordingly, the length of the pipe 1 is greater than the height of the mast of the lifting installation, the pipe 1 is collected at the wellhead from several pipes, connecting them with thread or welding.

Thus, the proposed utility model allows to simplify the design of the device and increase its tightness.

Claims (2)

1. A device for repairing a casing string in a well, comprising a drive with two expanding punches placed on one rod, and an expandable nozzle with a reduced inner diameter of the end sections, characterized in that the inner diameter of the end sections of the pipe is reduced by narrowing it without increasing the thickness moreover, the narrowed end sections of the pipe are pre-expanded at the ends to a length of at least two wall thicknesses of the pipe at its ends, and on the outside they are wearing elastic seals made e in the form of a thin-walled cylindrical shell and secured against movement with one end through the flange sleeve, wherein the upper punch set beneath the upper end portion at a distance sufficient to expand the lower end portion. 2. A device for repairing a casing string in a well according to claim 1, characterized in that for blocking long sections of the casing string, the nozzle is made of several pipes connected to the wellhead by threading or welding.