RU2242582C2 - Device for pressurization of torn column in a well (variants) - Google Patents

Abstract

FIELD: underground well maintenance.

SUBSTANCE: device has tail piece provided with sub in upper portion with thread for removing tool during raising from well. Tail piece is made consisting of upper and lower portions, between which fixing elements in form of spring plates are placed, on external surface thereof flat fixers are placed, made with possible support against upper end of lower portion of torn column. Lower portion of tail piece is made with slant, while height of fixers is greater than space between column pipes, connected by sleeves. According to second variant, tail piece is made perforated and with ring recess placed in its center, in which fixers are placed in form of spring-loaded plates, made with possible support against upper end of lower portion of torn column. Lower portion of tail piece is made with slant. Height of fixers is greater than space between column pipes, connected by sleeves. According to third variant, upper and lower portion of tail piece are connected by inner bushing with forming of ring space. Tail piece is provided with fixer on its outer surface in ring recess, in form of T-shaped cross-section stopping spring ring, with possible support against upper end of lower portion of torn column. Height of fixer is greater than space between column pipes, connected by sleeves.

EFFECT: higher reliability.

3 cl, 7 dwg

Description

The invention relates to techniques and technologies for underground well repair, and in particular to devices for sealing fractured and displaced operational casing strings of oil, water and gas wells.

In practice, cases have been recorded when the casing string during operation of the well has a gap with a gap along the axis and with an offset in the cross section.

So, for example, well No. 4 of the Novo-Alekseevskoye field of the Maykop UDTG of Kubangazprom LLC. The total depth of the well is 4300 m, the string is lowered to the level of 4295 m, the artificial cement bridge is at a depth of 3940 m, the perforation interval (productive layer) is 3915-3925 m, the cement slurry in the annulus is raised to the level of 2278 m. This well has a transverse depth at 2014 m rupture of the casing string with a diameter of 140 mm with a gap (gap) along the axis of 800 mm and with a displacement in the cross section within 50 mm (figure 1).

A device for sealing a casing string is known, including lowering the complete assembly with the patch on the tool into the well, orienting the patch to rupture, creating excessive hydraulic pressure in the device and expanding the patch to mate the casing string with the turning head from top to bottom with a power pusher when applying wellhead / 1 /.

A device for repairing a casing string is known, including a corrugated patch with end seals on the rod and descent into the well after filling the cavity of the patch with a working agent NRS-1 (SIGB) on a water basis, the orientation of the patch against fracture, the process of swelling of the NRS-1, allowing the patch to expand to contact with the casing / 2 /.

However, these devices do not restore the centering of the transverse fracture of the casing with a gap (gap) along the axis by a significant amount and do not provide the strength of the repaired fracture of the casing from being crushed by external pressure due to the thinness of the patch, and therefore, the sealing of the string will not be achieved.

The closest in technical essence and the achieved result is a device for closing the casing rupture with pipes of smaller diameter (installation of shanks, flares) with subsequent cementing in the annulus, containing a shank equipped with a threaded adapter in the upper part for turning the tool up when lifting it from the well / 3 /.

The known device does not allow to center the broken and shifted in cross section sections of the string, since the lower end of the liner (flies) when running into the well abuts against the upper end of the broken and shifted lower part of the casing. And, as a result, the permeability of the tool is not restored, leakage of the column is not eliminated, the return of the well to the existing fund is not provided, the well is liquidated.

The technical result of the invention is the restoration of the patency of the tool, the elimination of leaks in the torn production casing string and the return of the well to the existing fund.

The technical result can be achieved by implementing one of three options by the fact that:

1. in a known device for sealing a broken column in a well containing a liner provided with a threaded adapter in the upper part for turning the tool when lifting it from the well, according to the invention, the liner is made up of upper and lower parts, between which are fixed spring elements plates, on the outer surface of which are flat clamps, made with the possibility of support on the upper end of the lower part of the broken column, while the lower part of the shank is made Helen with a bevel, and the height of the clamps is greater than the gap between the pipes of the column connected by couplings;

2. in a known device for sealing a broken column in a well containing a shank provided with a threaded adapter in the upper part for turning the tool when lifting it from the well, according to the invention, the shank is perforated and has a recess located in its center along the ring in which clamps in the form of squeezing spring petals, made with the possibility of support on the upper end of the lower part of the broken column, while the lower part of the shank is made with a bevel, and the height of the clamps is greater the gap between the pipes of the column connected by couplings;

3. in a known device for sealing a broken column in a well containing a shank provided with a threaded adapter in the upper part for turning the tool when lifting it from the well, according to the invention, the shank is perforated, consisting of upper and lower parts connected by an inner center sleeve with the formation of an annular gap and provided on its outer surface in the annular gap with a latch in the form of a T-shaped in cross section of the retaining spring ring, made with the possibility of s on the upper end of the lower part of the broken string, the lower portion of the shank is provided with a bevel, and the height of the retainer over the gap between the pipe string connected couplings.

Figure 1 shows the imprint 1 of the displacement of the lower part relative to the upper part of the broken column on the end seal 2.

Figure 2 presents a General view of the device (option 1) in the transport position in a longitudinal section without the upper and lower parts of the liner during descent into the well.

Figure 3 - the device is in the operating position at the time of fixation of the torn production casing after alignment along the axis.

Figure 4 presents a General view of the device (option 2) in the transport position in a longitudinal section without upper and lower parts of the liner during descent into the well.

Figure 5 - the device is in the working position at the time of fixation of the torn production casing after alignment along the axis.

Figure 6 presents a General view of the device (option 3) in a longitudinal section in the transport position without the upper and lower parts of the liner during descent into the well.

In Fig.7 - the device is in the working position at the time of fixation of the torn production casing after alignment along the axis.

The proposed device according to option 1 (FIGS. 2 and 3) consists of a lower 1 with a bevel and an upper 2 parts of the shank, interconnected by fixing elements in the form of spring plates 3, on the outer surface of which there are latches 4. The latches 4 are made flat, the height of which more gaps between the casing pipes connected by couplings, not less than 1.5 times. The latches 4 are based on the upper end of the lower part of the torn columns.

The device according to option 2 (FIGS. 4 and 5) consists of a solid shank 6 with perforation 7 and a recess in the ring 8, in which the latches 9 are located in the center of the shank.

The latches 9 are made in the form of squeezing spring petals, the height of which is greater than the gaps between the casing pipes connected by couplings at least 1.5 times.

The device according to option 3 (FIGS. 6 and 7) consists of a shank 10 with an inner central hub 11 and a perforation 12, a retainer 13 in the form of a locking T-ring. The height of the latch is greater than the gaps between the casing pipes connected by couplings, not less than 1.5 times.

The shank in all cases has: in its lower part, a bevel, with which the rotation of the tool ensures that the device enters the lower part of the broken and shifted production casing and its centering along the axis, in the upper part there is a sub with left (right) thread for turning the tool when his ascent from the well.

The device operates as follows.

The device on the tool (tubing or drill pipe) is lowered into the well to the fracture site of the production casing 5 and the rotation and weight of the tool provide, due to the bevel in the liner, the liner to enter the lower part of the broken string.

Upon exit, the retainers 4 (option 1, FIGS. 2 and 3) and the retainers 9 (option 2, FIGS. 4, 5), and the retainer 13 (option 3, FIG. 6, 7) from the top of the broken column 5 in space, possessing the properties of a constrained spring, they extend radially and rest on the upper end of the lower part of the broken column, thereby securing the shank and the passage of the tool through the shank in the gap interval.

After this, turning the tool to the left (right) from the shank and lifting it to the surface.

Then, in a known manner, cementing is carried out behind the column, the time for hardening the grouting (cement) mortar, drilling out the remains of the hardened mortar, crimping and other technological operations for putting the well into operation are maintained.

Using the proposed technical solution will allow to restore the patency of the tool, eliminate leaks in the operational casing string and return the well to the existing fund.

The economic effect of using the proposed invention exceeds several times in comparison with the construction of a new well.

Sources of information

1. Patent RU 2154149, 2000.

2. SU 1538581, 1989.

3. Suleymanov A.B. and others. Technique and technology of overhaul of wells. - M .: Nedra, 1987, p. 236-238.

Claims (3)

1. A device for sealing a broken column in a well, comprising a shank provided with a threaded adapter in the upper part for turning the tool when lifting it from the well, characterized in that the shank is made up of upper and lower parts, between which are fixed elements in the form of spring plates, on the outer surface of which are flat retainers, made with the possibility of support on the upper end of the lower part of the broken column, while the lower part of the shank is made with a bevel m, and the height of the clamps is greater than the gap between the pipes of the column connected by couplings. 2. A device for sealing a broken column in a well, comprising a shank provided with a threaded adapter in the upper part for turning the tool when lifting it from the well, characterized in that the shank is perforated and has a recess located in its center along the ring in which the latches are located in the form of squeezing spring petals, made with the possibility of support on the upper end of the lower part of the broken column, while the lower part of the shank is made with a bevel, and the height of the clamps is greater than the gap between the tubing connection of the coupling. 3. A device for sealing a broken string in a well, comprising a shank provided with a threaded adapter in the upper part for turning the tool when lifting it from the well, characterized in that the shank is perforated, consisting of upper and lower parts connected by an inner sleeve to form an annular the gap, and is provided on its outer surface in the annular gap with a latch in the form of a T-shaped in cross section of the retaining spring ring, made with the possibility of support on the upper end face It torn portion of the column, the lower part of the shank is provided with a bevel, and the retainer height is greater than the gap between the pipe string connected couplings.

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