METHOD FOR REPAIRING A TUBULAR

Abstract

A method for lining at least a portion of the inner wall of an upstanding tubular includes inserting a liner sleeve into the tubular. The liner sleeve includes a sleeve of flexible sheet material impregnated with and/or coated with a curable polymer composition. The liner sleeve is held in a tubular and a liner sleeve locating tool is inserted into the tubular and inside the liner sleeve. Operating the liner sleeve locating tool holds the outer surface of the liner sleeve in contact with the inner surface of the tubular; and curing the polymer composition bonds the liner sleeve to the inner wall. Alternatively the liner sleeve may be filled with fluid to hold its outer surface in contact with the tubular to allow curing and bonding

Claims

1. A method for lining at least a portion of the inner wall of an upstanding tubular; the method comprising: a) inserting a liner sleeve into a said tubular; wherein the liner sleeve comprises a sleeve of flexible sheet material impregnated with and/or coated with a curable polymer composition; b) holding the liner sleeve in the tubular; c) inserting a liner sleeve locating tool into the tubular and inside the liner sleeve; d) operating the liner sleeve locating tool to hold the outer surface of the liner sleeve in contact with the inner surface of the tubular; and e) curing the curable polymer composition to bond the liner sleeve to the inner wall of the upstanding tubular.

2. The method of claim 1 further comprising the step of: f) removing the liner sleeve locating tool.

3. The method of claim 1 wherein the liner sleeve locating tool is an inflating tube of a flexible sheet material that has a closed or closable end and is inflatable by a fluid; and, optionally, wherein, in use, the inflating tube extends to at least the full length of the liner sleeve.

4. (canceled)

5. The method of claim 1 wherein the liner sleeve locating tool is an inflating tube of a flexible sheet material that has a closed or closable end and is inflatable by a fluid; and, the fluid employed to inflate the inflating tube is water; and, optionally, wherein the inflating tube is pressurised with fluid when inflated.

6. (canceled)

7. The method of claim 1 wherein the inflating tube is inflated and deployed down the tubular in a single process step; and, optionally, wherein the single process step is commenced after; the end of the inflating tube distal to the closed or closable end is held open at or above the upper end of the tubular; the inflating tube is at least partly turned inside out with the length of the inflating tube extending downwards from its held open end and then turning inwards and then upwards away from the held open end to the closed or closable end; thereby providing a turned up end; and, optionally, wherein the single process step includes: introducing liquid into the turned up end as the inside out portion of the inflating tube is fed into the held open end, to deploy the inflating tube down into the tubular.

8. (canceled)

9. (canceled)

10. The method of claim 5 wherein the inflating tube is allowed to turn substantially completely the right way out.

11. The method of claim 1 wherein the liner sleeve locating tool is an inflating tube of a flexible sheet material that has a closed or closable end and is inflatable by a fluid; and wherein after the curable polymer composition is cured the inflating tube is removed from the tubular by withdrawing by use of a cable attached to the closed or closable end.

12. The method of claim 1, wherein the liner sleeve locating tool is an inflating tube of a flexible sheet material that has a closed or closable end and is inflatable by a fluid; and wherein the inflating tube is not removed from the tubular.

13. The method of claim 1 wherein a housing is fitted to the top end of the tubular.

14. The method of claim 1 wherein the liner sleeve is held in the tubular by fixing the upper end of the liner sleeve at or near the upper end of the tubular.

15. The method of claim 1 wherein the flexible sheet material of the liner sleeve comprises a fabric that is woven, non-woven, or knitted in construction.

16. The method of claim 11 wherein the fabric is a glass fibre fabric.

17. The method of claim 1 wherein the curable polymer composition is a curable epoxy resin polymer.

18. The method of claim 1 wherein the flexible sheet material of the liner sleeve includes one or more strength members, attached to or inside the flexible sheet material.

19. The method of claim 1 wherein the flexible sheet material of the liner sleeve is impregnated with and/or coated with the curable polymer composition by one of: passing through a bath of the curable polymer composition; contacting at least one coating roller coated the curable polymer composition; and spraying with the curable polymer composition.

20. The method of claim 1 wherein the liner sleeve is deployed by a machine including a drum for holding the liner sleeve before deployment; and drive means to move the liner sleeve from the drum and down an upstanding tubular; and, optionally, wherein the machine includes a coating station for coating and/or impregnating the flexible sheet material of the liner sleeve with the curable polymer composition; and, optionally, wherein the drive means includes drive rollers.

21. (canceled)

22. (canceled)

23. The method of claim 1 wherein the liner sleeve is held in the tubular by fixing the upper end of the liner sleeve at or near the upper end of the tubular; and wherein the liner sleeve is held in the tubular by the liner sleeve locating tool; and, optionally, wherein the liner sleeve locating tool is fitted inside the liner sleeve before the liner sleeve is put into the tubular and the liner sleeve locating tool is lowered into the tubular with the liner sleeve held to its outer surface or surfaces.

24. (canceled)

25. The method of claim 17 wherein the liner sleeve locating tool comprises an inflatable tube or other shaped bladder of flexible sheet material fitted to a base.

26. The method of claim 17 wherein the liner sleeve locating tool comprises panels that move radially outwards to hold the liner sleeve against the tubular.

27. A method for lining at least a portion of the inner wall of an upstanding tubular; the method comprising: a) inserting a liner sleeve into a said tubular; wherein the liner sleeve comprises a sleeve of flexible sheet material impregnated with and/or coated with a curable polymer composition and has a closed or closable end; b) holding the liner sleeve in the tubular with the closed or closable end distal to the top end of the tubular; c) filling the liner sleeve with fluid to hold the outer surface of the liner sleeve in contact with the inner surface of the tubular; d) curing the polymer composition to bond the liner sleeve to the inner wall of the upstanding tubular; and e) opening the closed or closable end of the liner sleeve.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0057] FIG. 1 a shows in schematic partial perspective, a liner sleeve being inserted into a tubular;

[0058] FIGS. 1b and 1c show in cross section, a liner sleeve inside a tubular;

[0059] FIG. 1d shows in schematic partial perspective (cut-away), a liner sleeve in a tubular;

[0060] FIG. 2 shows in in schematic partial cross section, the deployment of an inflating tube in a tubular containing a liner sleeve;

[0061] FIG. 3 shows in schematic partial cross section, an inflating tube end inside a tubular;

[0062] FIG. 4 shows in schematic perspective, a machine for liner sleeve deployment;

[0063] FIGS. 5 and 5a show an alternative machine for liner sleeve deployment;

[0064] FIGS. 6a to 6e show in schematic partial perspective views, clamping arrangements; and

[0065] FIG. 7 shows in schematic partial perspective view (cut-away) deployment of a sleeve liner in a tubular using a liner sleeve locating tool.

DESCRIPTION OF THE INVENTION WITH REFERENCE TO SOME EMBODIMENTS

[0066] FIG. 1a shows in a partial schematic perspective view an upstanding tubular 1, such as a caisson as can be found on an offshore oil platform, passing through a floor 2, towards the sea (not shown, in the direction of arrow S). A liner sleeve 4 of a woven flexible sheet material that has been impregnated with a curable polymer composition is being fed into the top end 6 of tubular 1. The woven texture of liner sleeve 4 is suggested only by a small area of cross hatch 8, for clarity and simplicity.

[0067] FIG. 1b shows the tubular 1 of FIG. 1 a in a plan view, to show the folding of liner sleeve 4 that allows it to pass easily down the tubular. FIG. 1c shows an alternative folding arrangement where the liner sleeve 4 has a single inwardly directed longitudinal fold 10 that allows the liner to adopt a generally heart shaped cross sectional shape, of reduced diameter.

[0068] FIG. 1d shows a schematic cross-sectional view of tubular 1 with liner sleeve 4 deployed inside the tubular. The top end 12 of the liner sleeve is held open by being turned over the top edge 14 of the tubular to form a turned over end 16.

[0069] As can be seen in schematic cross section FIG. 2, the turned over end 16 may be clamped into place at the top of the tubular 1 as suggested by arrows C (see also FIG. 6a). Also shown in this figure is an inflating tube 18 (see also FIGS. 3 and 5). The inflating tube 18 has a held open end 20 turned over around the top edge 14 of the tubular 14 in this example. Again clamping in place is suggested by arrows C. The inflating tube 18 extends down into the tubular 1, inside the liner sleeve 4, for a short distance before turning inside out and upwards to form turn up 22. The inside out portion 24 of the inflating tube 18 extends upwards and then around pulley wheel 26 to one side, where the inflating tube ends at a closed end 28 which attaches to the cable 30 of a hoist (not shown, see FIG. 4). As indicated by arrows D the inflating tube 18 is deploying by moving around pulley 26 and down into the tubular 1, assisted by water 27 from a source suggested by arrow W; that fills the turn up 22.

[0070] FIG. 3 shows the bottom end 32 of tubular 1 in schematic cross section. In this view the inflating tube 18 is filled with water 27 and fully deployed. The liner sleeve 4 is held in good contact with the inner wall of the tubular 1 until it has cured. After curing is complete the inflating tube is recovered, as suggested by arrow R, from tubular 1 by use of the cable 30 attached to a hoist (not shown). In this example an openable panel 34 at the bottom of the inflating tube 18 may be opened (for example by use of a probe or by cutting with a high pressure water jet), to allow water easy escape as the recovery of the inflating tube 18 is carried out. Alternatively the water in the inflating tube can be removed simply by pumping from the top, e.g. by suction pumps, as the inflating tube is removed or even before the inflating tube is removed. As a further alternative the action of withdrawing the inflating tube may be used to allow the water to overflow from the top of the tubular. In general a controlled exit of water is undertaken as is convenient for the task and location.

[0071] FIG. 4 shows in schematic perspective a machine for liner sleeve deployment 36. In this example a drum 38 is loaded with a folded sleeve of flexible sheet material 40 (such as of woven glass fibre), for dispensing via a series of rollers 42 and a coating station 44, down into the tubular 1, as in the schematic view of FIG. 1a. The coating station 44 includes bath 46 for a curable polymer composition. The sheet material 40 is impregnated with curable polymer composition in bath 46 before passing through drive rollers 48 which remove excess polymer composition.

[0072] FIG. 5 shows an alternative machine for carrying out the invention. In this example a more manual operation is contemplated. A drum 38 (see detail perspective FIG. 5a) is manually operated by crank handle 50 or by motor (not shown). The drum can be used to deploy a cable 52 attached to a closed end of an inflating tube 18.

[0073] In this example the drum 38 includes a reduced diameter central portion 54 that may be employed for coils of the cable 52. The reduced diameter portion may also find use for holding a sleeve of flexible sheet material 40 to be deployed down a tubular before the inflating tube 18 is put into position for its own deployment.

[0074] As shown in the figure cable 52 is deploying inflating tube 18 by means of a pulley assembly 56 mounted on a support assembly 58. The tubular 1 is shown in cross section in this figure to allow viewing of the contents. A liner sleeve 4 has already been deployed inside the tubular 1 and is in the process of being held against the inner surface of the tubular 1 by the inflating tube 18 as it descends (turns outside out) and is filled with water 27 from a source W, as suggested by arrow D.

[0075] In this example a cylindrical housing 60 is fitted to the top 6 of the tubular 1 and water inlets 62 deliver the water to the interior. After completion of the descent of the inflating tube 18 into the tubular 1, a lid 64, (shown in a raised position) may be fitted onto the top 66 of the housing 60 to allow slight pressurisation of the water 27 to firmly hold the liner sleeve 4 in position until the curable polymer composition it is impregnated and/or coated with, has completed curing. The lid 64 has a passage 65 through it to allow the cable 52 passage. After the lid 64 is put into place for pressurisation, sealant may be used around passage 65 to allow pressurisation.

[0076] Alternative arrangements may be made. For example a main cable 52 may attach to a lifting lug or padeye 67 on the top of lid 64 (see also FIG. 6e). A similar lug (not shown) on the underside of the lid 64 may have a secondary cable attached to it that connects to the inflating tube 18 in the same way as cable 52 does in the arrangement depicted in the figure.

[0077] The liner sleeve 4 is held at the top 6 of the tubular 1 by clamping ring 68. The inflating tube 18 is similarly held by clamping ring 70 at the top of the housing 60. (See FIGS. 6a to 6e)

[0078] After curing of the polymer composition the lid 64 may be removed and the water 27 may be pumped out or simply allowed to overflow out as the inflating sleeve 18 is retrieved as suggested by the arrow R, making use of the cable, pulley and drum system 52, 56, 50. The inflating tube 18 peels away from the liner sleeve 4. The housing 60 and other components of the system may then be removed.

[0079] FIGS. 6a to 6e illustrate the clamping arrangements in partial schematic perspective views.

[0080] In FIG. 6a, a tubular 1 passing through a floor 2 or deck of an installation; such as an oil rig; has a liner sleeve 4 deployed down through its interior. The top 12 of liner sleeve 4 has been turned over the top edge 6 of the tubular and is being secured in place by a clamping ring 68.

[0081] As can be seen in FIG. 6b the clamping ring 68 may be employed to also clamp housing 60 to the top of the tubular 6.

[0082] In FIG. 6c the arrangement has an inflating tube 18 fitted inside the liner sleeve 4 which is being clamped by clamp ring 70 to the top of the housing 60. FIG. 6d shows the fitting of a lid 64 to the housing 60 to allow water pressurisation through water inlets 62 (only one visible).

[0083] FIG. 6e shows lid 64 and clamp ring 70 in place and in more detail. Also shown is lug 67 for attachment of a cable.

[0084] FIG. 7 shows in partial cut away perspective an arrangement for lining a tubular 1 making use of a liner sleeve locating tool to carry the liner sleeve 4 down the tubular 1 and then hold it against the interior surface of the tubular to allow curing and bonding.

[0085] As can be seen in the figure, in this example a liner sleeve locating tool 72 includes a cylindrical base 74 (typically of metal) about which an inflatable bladder 76 is disposed. The tool 72 has been deployed down the tubular 1, suspended on cable 52. A liner sleeve 4 coated and/or impregnated with a curable polymer composition is disposed around bladder 74, and held by slight tension caused by partial inflation of the bladder via pipe 78. The inflating fluid employed may be water or a gas for example. The liner sleeve is held at the depth of a defect, such as a hole, in the tubular 1. This is suggested here by dashed line 78. The bladder 74 is then inflated further to hold the liner sleeve firmly against the tubular until the curable polymer composition is cured. The bladder 74 may then be deflated and the tool 72 retrieved (as suggested by arrow R). If required eyelet 80 may be used for attachment of a ballast weight, as an aid to deployment (suggested by arrow D).