WO2010040790A2

WO2010040790A2 - Apparatus and method for deforming the shape of a tubular element

Info

Publication number: WO2010040790A2
Application number: PCT/EP2009/063062
Authority: WO
Inventors: Wilhelmus Christianus Maria Lohbeck
Original assignee: Dynamic Dinosaurs B.V.
Priority date: 2008-10-07
Filing date: 2009-10-07
Publication date: 2010-04-15
Also published as: WO2010040790A3; GB2464275A; GB0818322D0

Abstract

An apparatus (10, 32, 46, 56, 66, 70) for deforming the shape of a tubular element (12) which comprises a compressible expansion body (18, 36, 50, 60, 66, 74) being locatable in proximity to an inner surface or an outer surface of a tubular element, the compressible expansion body being mountable on a tool body (16, 34, 48, 58, 72); at least one outer surface of the expansion body being contactable with the inner surface or the outer surface of the tubular element when the expansion body is in its uncompressed state, the tool body being moveable longitudinally along the tubular element; the expansion body being compressible against the inner surface or the outer surface of the tubular element by the longitudinal movement of the tool body longitudinally along the tubular element; and the compression of the expansion body against the inner surface or the outer surface of the tubular element causing deformation of the shape of the tubular element so as to change its diameter longitudinally along a portion of the tubular element.

Description

APPARATUS AND METHOD FOR DEFORMING THE SHAPE OF A TUBULAR

ELEMENT

Technical field

[0001] This invention relates to apparatus and methods for deforming the shape of a tubular element. More particularly the invention relates to apparatus and methods for deforming the shape of a tubular element such as a casing, pipe or other tubular element typically installed in oil or gas wells, or the like.

Background art

[0002] Tubular elements are used in various industries, particularly for the transport of fluids. In the oil and gas industries tubular elements such as casing and completion tubing, pipe, screens and other such devices are well known. In order for these tubular elements to be installed in a well, it is necessary that they have an outer diameter that is less than the inner diameter of the borehole in which they are to be installed. In fact, since the inner diameter of the borehole can vary and the trajectory of the borehole is often not straight, the maximum possible diameter can be significantly less than that of the borehole at any point.

[0003] When a borehole is being drilled, it is usually necessary to stop drilling after a certain depth and stabilise the borehole by placing a steel tubular casing in the well and filling the annulus between the outside of the casing and the borehole wall with cement. This operation may need to be repeated several times during the drilling of the well, each successive casing being necessarily smaller than the inside diameter of the preceding casing. This in turn leads to progressive reduction of the inner open diameter of the well which in turn places limitations on the quantities of fluids that can flow along the well.

[0004] To overcome this problem, it has been previously proposed to expand the casing in the well to reduce the annular space. Also, expansion of subsequent casings to match the diameter of the previous casing has also been proposed to avoid the progressive diameter reduction found with conventional casing techniques. [0005] Expansion is typically achieved using a cone shaped expanding tool which has a maximum diameter that is greater than the inside diameter of the casing to be expanded. Forcing the expanding tool through the casing causes it to expand. One difficulty in this operation is that because the outer diameter of the expansion tool is greater than the inner diameter of the casing, it is not possible to position the expanding tool in the casing; it must either start at the top or bottom and be moved either to the other end or back to its starting place to be removed from the casing. To address this, expanding tools have been proposed that are initially positioned in a contracted state and then are reconfigured into their operational configuration before being moved through the casing. However, since the outer diameter is typically still greater than the inner diameter of the casing, this must be done in an open section of the well or in a section of wider diameter. There are currently expanding tools which have smaller outer diameters than the inner diameter of the casing, but the deployment forces are not enough to start expansion.

[0006] It is an object of this invention to provide a method by which expansion can be initiated in a section of the casing or other tubular in its unexpanded state and so can create either a complete expansion, or a chamber in which a conventional expanding tool can be deployed. This invention achieves this object by the use of a compressible member on an expanding tool that can be squeezed to provide an expansion surface on an expanding tool that can fit in the unexpanded tubular element.

[0007] It is a further object of the invention to provide apparatus and methods for deforming the shape of tubular elements where lubrication of the deformation components is easier and improved over those in the art as the movement providing deformation of the tubular elements takes place in a closed or confined chamber with a sealed arrangement.

[0008] It is yet a further object of this invention to provide various applications of the expansion apparatus, some of which reduce or avoid the need for the use of cementing in wells.

Disclosure of the invention [0009] One aspect of this invention provides an apparatus for deforming the shape of a tubular element, comprising:

- a compressible expansion body being beatable in proximity to an inner surface or an outer surface of a tubular element, the compressible expansion body being mountable on a tool body;

- at least one outer surface of the expansion body being contactable with the inner surface or the outer surface of the tubular element when the expansion body is in its uncompressed state;

- the tool body being moveable longitudinally along the tubular element;

- the expansion body being compressible against the inner surface or the outer surface of the tubular element by the longitudinal movement of the tool body longitudinally along the tubular element; and

- the compression of the expansion body against the inner surface or the outer surface of the tubular element causing deformation of the shape of the tubular element so as to change its diameter longitudinally along a portion of the tubular element.

[0010] In one form of the invention the expansion body is beatable inside a tubular element and is compressible against the inner surface of the tubular element so as to cause deformation of the tubular element by expansion and an increase in the diameter of the tubular element.

[0011] In another form of the invention the expansion body is beatable on the outside of a tubular element and is compressible against the outer surface of the tubular element so as to cause deformation of the tubular element by expansion and a decrease in the diameter of the tubular element.

[0012] The expansion body may comprise at least one ring. The ring may be mounted coaxially on the longitudinal axis of the tool body and is moveable along the longitudinal axis from one end to the other end of the tool body. Each of the ends of the tool body includes a non-expanding region, where the ring is beatable in a non-compressed state and an expanding region located between the two ends, where the ring is compressible against the inner surface of the tubular element and is able to cause deformation of the tubular element. The ring is moveable between the two ends of the tool body in a rolling motion, the rolling motion being caused by the tool body being moved longitudinally through the tubular element.

[0013] The expansion body may be in the form of a sleeve which is mounted around the longitudinal axis of the tool body. The travel of the tool body through the sleeve may cause the expansion body to expand against the inner surface of the tubular element in which it is located.

[0014] The expansion body may be formed from an elastomeric material. Preferably, the elastomeric material is polyurethane.

[0015] Further according to the invention the compressible expansion body may be mounted on the tool body such that the diameter of the expansion body is substantially the same as at least part of the outer diameter of the tool body and means are provided for axially compressing the expansion body such that its outer surface is expanded beyond the outer diameter of the tool body. The compressible expansion body may be mounted on the tool body such that it is beatable in at least a portion of an end of the tubular element. Preferably the diameter of the end of the tubular element is increased by the expansion body causing deformation of the shape of the tubular element in its expanded state.

[0016] Even further according to the invention an expansion body may be beatable around the outside of the tubular element and the tool body is mounted around the expansion body such that the expansion body is substantially enclosed around the tubular element.

[0017] In this case the means for compressing the expansion member may comprise a set of inner surfaces on the tool body and at least one of the inner surfaces being moveable and arranged such that the expansion body can be squeezed between the inner surfaces of the tool body and the outer surface of the tubular element. Compression of the expansion body and squeezing it expands it against the outer surface of the tubular element. The tool body may include a cylinder in which a piston is slidably located, the moveable inner surface being formed on the piston, the tool body includes a cylinder in which a piston is slidably located, the moveable inner surface of the tool body being formed on the piston. [0018] The expansion body may be treated with lubricant. Further, there is preferably a protective structure beatable around at least a portion of the expansion body. The protective structure may be a cage.

[0019] The invention may further comprise means for moving the tool body longitudinally along the tubular element.

[0020] A further aspect of the invention provides for a bridge plug including an apparatus for deforming the shape of tubular elements as described above.

[0021] Another aspect of the invention provides a selective placement tool including an apparatus for deforming the shape of tubular elements as described above. The selective placement tool may include a plurality of apparatuses and the expansion body in each apparatus may be in its expanded state. Preferably, the selective placement tool is slidable.

[0022] A further aspect of the invention provides for a sand screen expanding device including an apparatus for deforming the shape of tubular elements as described above.

[0023] Both the selective placement tool and the sand screen expanding device may further include a protective structure.

[0024] Another aspect of the invention provides a method for deforming the shape of a tubular element, comprising:

- positioning an apparatus as claimed in any preceding claim at a predetermined position in close proximity to an inner surface or an outer surface of the tubular element; and

- compressing the expansion body such that its outer surface expands against the inner surface or the outer surface of the tubular element, and causes deformation of the shape of the tubular element so as to change its diameter longitudinally along a portion of the tubular element.

[0025] In one form of the invention the apparatus used in the method may be positioned on the inside of the tubular element. In another form of the invention the apparatus may be positioned on the outside of the tubular element.

[0026] The method according to the invention may further comprise moving the apparatus with the expansion body longitudinally along the tubular element to progressively deform a length of the tubular element. Even further the method may include releasing the expansion body from compression such that it returns to its uncompressed shape, moving the tool body to another location in the tubular element and repeating expansion of the tubular element at the other location.

[0027] Preferably, the method may further include protecting the expansion body around at least a portion of the expansion body.

[0028] In a further form of the invention the expansion body may be compressible by travel through an area which has an inner diameter which is less than the outer diameter of the compression body in its uncompressed state.

[0029] According to a further aspect of the invention there is provided an apparatus for deforming the shape of tubular elements, comprising an expansion body that is compressible by travel through an area inside a tubular element, where the tubular element has an inner diameter which is less than the outer diameter of the expansion body when the expansion body is in its uncompressed state.

[0030] Further according to the invention the expansion body may be compressible by a device which applies force directly to the expansion body.

[0031] Other uses will be apparent from the description below.

Brief description of the drawings

[0032] Figure 1 shows a schematic cut through side view of an apparatus for deforming the shape of tubular elements according to one embodiment of the invention;

Figure 2 shows a schematic side view of an apparatus for deforming the shape of tubular elements according to a second embodiment of the invention;

Figure 3 shows a schematic side view of an apparatus for deforming the shape of tubular elements according to a third embodiment of the invention;

Figure 4 shows a schematic side view of an apparatus for deforming the shape of tubular elements according to a fourth embodiment of the invention; Figure 5 shows a schematic side view of an apparatus for deforming the shape of tubular elements according to a fifth embodiment of the invention; and

Figure 6 shows a schematic side view of an apparatus for deforming the shape of tubular elements according to a sixth embodiment of the invention.

Mode(s) for carrying out the invention

[0033] Figure 1 shows an apparatus 10 according to a first embodiment of the invention located in a tubular element 12. Tubular element 12 may be, for example, a pipeline, casing, drillpipe or tubing such as those used in oil or gas wells, or the like. It is preferable that tubular element 12 be a thin tube, such as cladding, or a screen for easier expansion. Apparatus 10 comprises a tool body 16 and a compressible expansion body in the form of a ring 18 which may be made from an elastomeric material such as elastomeric polyurethane. Tool body 16 is shown to comprise two end portions 20 with an elongate shaft 22 extending between them. End portions 20 each include a terminal end section 24 and a non-expanding region 26 where the ring 18 is mounted in its non-compressed state. Elongate shaft 22 comprises the expanding region 28 of tool body 16 and has a larger diameter than that of the non-expanding region 26.

[0034] When mounted in the expanding region 28 the ring 18 is compressible against the inner surface of thin tubular element 12. This compression causes the ring 18 to expand against the inner surface 30 of the tubular element 12 and this expansion in turn causes deformation of the tubular element by increasing the diameter of the tubular element. The ring 18 is moveable between the two end portions 20 of the tool body 16 in a rolling motion. This rolling motion is shown by arrows A in a multiple stage progression. Ring 18 is shown to be moving over the tool body 16 when tool body 16 is moved longitudinally along in direction B through the tubular element 12.

[0035] It will be noted that while the apparatus 10 is transported to the position of interest in tubular element 12, ring 18 is retained in the non-expanding region 26. Once apparatus 10 has reached the position of interest in tubular element 12 where expansion is required, expansion is initiated by ring 18 being released from non-expanding region 26 and being pushed to expanding region 28.

[0036] Figure 2 shows an apparatus 32 according to a second embodiment of the invention located in a tubular element 12. Apparatus 32 comprises a tool body 34 and a compressible expansion body in the form of a sleeve 36 which may also be made from an elastomeric material such as elastomeric polyurethane. Sleeve 36 is mounted around the longitudinal shaft 38 and an enlarged section 40 of the tool body 34. Enlarged section 40 may be conical or spherical in shape. As can be seen sleeve 36 includes a middle elongate section 42 and two end sections 44 which have a smaller thickness than the middle elongate section 42. The enlarged section 40 of the tool body 34 is housed in one of the two end sections 44.

[0037] Travel of the tool body 34 through the sleeve 36 moves the enlarged section 40 from the one end section 44 to the other end section 44. During this movement the enlarged section 40 compresses the middle elongate section 42 of sleeve 36 and expands it against the inner surface 30 of the tubular element 12 in a longitudinal direction. In this way this section of tubular element 12 is expanded and its diameter is increased in this area. As indicated by directional arrow C in Figure 2, the tool body 34 may be moved in either direction along the longitudinal axis of tubular element 12. Once a particular section of tubular element 12 has been expanded in this way, apparatus 32 may be moved to another location in the tubular element 12 and the expansion of the tubular element 12 may be repeated at this other location.

[0038] In Figure 3 an apparatus 46 according to a third embodiment of the invention located in a tubular element 12 is shown. Apparatus 46 comprises a tool body 48 and a compressible expansion body in the form of a sleeve 50 which may also be made from an elastomeric material such as elastomeric polyurethane. Sleeve 50 is mounted on the tool body 48 so that it extends from an end portion 52 into the end 54 of the tubular element 12. The diameter of the sleeve 50 is substantially the same as the outer diameter of the end portion of the tool body 48. Tool body 48 includes an elongate portion 51 and end portion 52, which has means for axially compressing sleeve 50 such that its outer surface is expanded beyond the outer diameter of tool body 48, as shown in Figure 3. Elongate section 51 slides into tubular element 12 when a compression force is applied during expansion. The result of this expansion is that the diameter of an end 54 of tubular element 12 is increased by the expansion body in its expanded state.

[0039] Figure 4 shows an apparatus 56 according to a fourth embodiment of the invention located in a tubular element 12. Apparatus 56 comprises a tool body 58 and a compressible expansion body in the form of a sleeve 60 which may also be made from an elastomeric material such as elastomeric polyurethane. Tool body 58 has an enlarged portion 64 along a portion of its longitudinal axis. Sleeve 60 is located on the inside of the tubular element 12 and is kept in place inside tubular element 12 by means of steel end plates 62. As tool body 58 travels longitudinally through tubular element 12 the enlarged portion 64 compresses the sleeve 60 in that area and causes sleeve 60 to expand against the inner surface 30 of tubular 12. This leads to the expansion of tubular element 12 and thus an increase in the diameter of tubular element 12 as apparatus 56 moves through it. As shown by arrow D in Figure 4, tool body 58 may move through the tubular element 12, in either direction.

[0040] An apparatus according to a fifth embodiment of the invention is shown in Figure 5 located in a tubular element 12. Tubular element 12 may, for example, be a thin walled pipe used for cladding in this instance and may itself then be located inside another pipe 68. In this embodiment the apparatus is a ball 66 of elastomeric material such as elastomeric polyurethane which may be forced down the inside of tubular element 12. For example, ball 66 may be forced through tubular element 12 by compressed air which can be forced through the tubular element 12 by a compressor, or ball 66 may be forced through tubular element 12 by a ram type device. The ball 66, in its uncompressed state, has a general diameter that is larger than the internal diameter of tubular element 12. Thus when it is forced through tubular element 12, it expands against the inner wall 30 of tubular element 12 and causes tubular 12 to expand against pipe 68.

[0041] Figure 6 shows an apparatus 70 according to a sixth embodiment of the invention located in a tubular element 12. Apparatus 70 comprises a tool body 72 and a compressible expansion body in the form of a ring 74 which may also be made from an elastomeric material such as elastomeric polyurethane. It will be understood that ring 74 may also comprise a thickened sleeve. Tool body 72 includes a set of inner surfaces forming an inner region 76, in which ring 74 is located. One of the inner surfaces in the inner region 76 is the head 78 of a piston 80 that is located in tool body 72. Ring 74 may be squeezed between the inner surfaces inside region 76 by the head 78 of piston 80 being forced against and compressing ring 74, in the direction E, as shown in Figure 6. This compression leads to ring 74 being compressed onto the outer surface of tubular element 12 and this leads to the contraction or crimping of tubular element 12. In this way the diameter of tubular element 12 may be decreased in these areas. This crimping may be used at the end of pipes so that they may be fitted into other pipes or it may be used in areas where other equipment is to be fitted around the outside of the tubular element 12 so as to grab hold of it securely.

[0042] The compressible expansion body of the invention may be protected from damage or wear in use by a protective structure (not shown), such as a cage or other covering structure. The protective structure protects the expansion body from wear and damage caused by abrasion and friction when it is in its expanded state and it is being used to deform or expand a tubular element such as a pipe.

[0043] There may be various ways in which apparatus 70 may be moved or transported from one location on a tubular element 12 to another location on the tubular element 12. These forms of transport that can be used with the current invention are well known in the art for use in moving various types of apparatus along and through tubular elements such as pipes or casing. [0044] The invention as illustrated in Figure 6 is preferably applied to tubular elements 12 in the form of a pipeline. Use of the invention in a larger diameter tubular element such as a well is less practical as the outer diameter of apparatus 70 would have to be too large and thus the material from which the compressible expansion body is made would not function correctly.

[0045] The invention may be applied to various types and sizes of tubular elements. These tubular elements to which the invention is applied may thus be of different thicknesses, may be made of different types of materials and may be solid, perforated or slotted, or may be tubular screens, depending on their use and application.

[0046] The apparatus and methods for deforming the shape of a tubular element may have a number of applications. One such application of the apparatus of the invention is for a bridge plug which is used to isolate the lower part of a wellbore. The bridge plug may be permanent, enabling the lower part of the wellbore to be permanently sealed off from production, or it may be retrievable enabling the lower part of the wellbore to be temporarily isolate from the treatment conducted on an upper zone of the wellbore. The tubular element expanded by the bridge plug may be an additional tubular element inside the casing or liner.

[0047] Another application of the apparatus of the invention is for a selective placement tool, such as a selective chemical placement tool. The selective placement tool is typically made up of a plurality of apparatuses of the invention and the expansion body in each apparatus is used in its expanded state.

[0048] The selective chemical placement tool is typically deployed downhole by coiled tubing, workstring or other conduit. The selective chemical placement tool may be slidably displaceable. In use the selective chemical placement tool is deployed to a particular area of interest and then expansion takes place by the expanding apparatus so that the tool is anchored in the casing or liner across an area to be treated. Chemical fluid is then injected into the body of the tool between its two outer sections and this chemical fluid may then be able to enter areas outside of the casing or liner, which is in the annulus, by squeezing to perform various chemical treatments such as, for example, sand consolidation and chemical shut-off. Once the chemical treatment has been performed, the selective chemical placement tool may then be slidably displaced to another location and then be anchored at that position so that another chemical treatment may be performed at this location. In this way the selective chemical placement tool may be moved sequentially down the wellbore to perform sequential chemical treatments where required. The selective chemical placement tool of the invention will allow for improved profile control. The selective placement tool may be used in through tubing applications using the flip-over high expansion ratio system as a sliding plug. It may further be covered by a metal wear cage or supportive structure for added protection against damage or wear that occurs during use.

[0049] Another application of the apparatus is for a sand screen. In this application, as well as in other applications, it is preferable to have a cage or supportive structure surrounding and covering the compressible expansion body so that the body is provided with added protection against damage or wear that occurs during use.

[0050] Further applications of the apparatus and methods according to the invention may be used in a wide range of technologies other than the oil and gas industries. Examples of these applications are: use in pipeline connections, corroded pipeline cladding, and in a hydro-forming mode forging profiles. A further application is also in the manufacturing of convectors (central heating systems) by expanding or connecting steel plates to a conduit through minor expansion of this conduit. In this application, expansion of such a hot water conduit locks perpendicular convector plates to the conduit.

Claims

1. An apparatus for deforming the shape of a tubular element, comprising:

- the tool body being moveable longitudinally along the tubular element;

2. An apparatus as claimed in claim 1 , wherein the expansion body is beatable inside a tubular element and is compressible against the inner surface of the tubular element so as to cause deformation of the tubular element by expansion and an increase in the diameter of the tubular element.

3. An apparatus as claimed in claim 1 , wherein the expansion body is beatable on the outside of a tubular element and is compressible against the outer surface of the tubular element so as to cause deformation of the tubular element by expansion and a decrease in the diameter of the tubular element.

4. An apparatus as claimed in any of the preceding claims, wherein the expansion body comprises at least one ring.

5. An apparatus as claimed in claim 4, wherein the ring is mounted coaxially on the longitudinal axis of the tool body and is moveable along the longitudinal axis from one end to the other end of the tool body.

6. An apparatus as claimed in claim 5, wherein each of the ends of the tool body includes a non-expanding region, where the ring is beatable in a non- compressed state and an expanding region located between the two ends, where the ring is compressible against the inner surface of the tubular element and is able to cause deformation of the tubular element.

7. An apparatus as claimed in claim 6, wherein the ring is moveable between the two ends of the tool body in a rolling motion, the rolling motion being caused by the tool body being moved longitudinally through the tubular element.

8. An apparatus as claimed in any of claims 1 to 3, wherein the expansion body is in the form of a sleeve which is mounted around the longitudinal axis of the tool body.

9. An apparatus as claimed in claim 8, wherein the travel of the tool body through the sleeve causes the expansion body to expand against the inner surface of the tubular element in which it is located.

10. An apparatus as claimed in any of the preceding claims, wherein the expansion body is formed from an elastomeric material.

11. An apparatus as claimed in claim 10, wherein the elastomeric material is polyurethane.

12. An apparatus as claimed in claim 2, wherein the compressible expansion body is mounted on the tool body such that the diameter of the expansion body is substantially the same as at least part of the outer diameter of the tool body and means are provided for axially compressing the expansion body such that its outer surface is expanded beyond the outer diameter of the tool body.

13. An apparatus as claimed in claim 12, wherein the compressible expansion body is mounted on the tool body such that it is beatable in at least a portion of an end of the tubular element and the diameter of the end of the tubular element is increased by the expansion body causing deformation of the shape of the tubular element in its expanded state.

14. An apparatus as claimed in claim 3, wherein an expansion body is beatable around the outside of the tubular element and the tool body is mounted around the expansion body such that the expansion body is substantially enclosed by the tool body around the tubular element.

15. An apparatus as claimed in claim 14, wherein the means for compressing the expansion member comprises a set of inner surfaces on the tool body, and at least one of the inner surfaces being moveable and arranged such that the expansion body can be squeezed between the inner surfaces of the tool body and the outer surface of the tubular element.

16. An apparatus as claimed in claim 15, wherein compression of the expansion body and squeezing it expands it against the outer surface of the tubular element.

17. An apparatus as claimed in claim 15 or 16, wherein the tool body includes a cylinder in which a piston is slidably located, the moveable inner surface of the tool body being formed on the piston.

18. An apparatus as claimed in any of the preceding claims, wherein the expansion body is treated with lubricant.

19. An apparatus as claimed in any of the preceding claims, which further includes a protective structure beatable around at least a portion of the expansion body.

20. An apparatus as claimed in claim 19, wherein the protective structure is a cage.

21. An apparatus as claimed in any of the preceding claims, further comprising means for moving the tool body longitudinally along the tubular element.

22. A bridge plug including an apparatus for deforming the shape of tubular elements as claimed in any of claims 1 to 21.

23. A selective placement tool including at least one apparatus for deforming the shape of tubular elements as claimed in any of claims 1 to 21.

24. A selective placement tool as claimed in claim 23, which includes a plurality of apparatuses and the expansion body in each apparatus is in its expanded state.

25. A selective placement tool as claimed in claim 23 or 24, which is slidable.

26. A selective placement tool as claimed in any of claims 23 to 25, which further includes a protective structure.

27. A sand screen expanding device including an apparatus for deforming the shape of a tubular element as claimed in any of claims 1 to 21.

28. A sand screen expanding device as claimed in claim 27, which further includes a protective structure.

29. A method for deforming the shape of a tubular element, comprising: - positioning an apparatus as claimed in any preceding claim at a predetermined position in close proximity to an inner surface or an outer surface of the tubular element; and

30. A method as claimed in claim 29, wherein the apparatus is positioned on the inside of the tubular element.

31. A method as claimed in claim 29, wherein the apparatus is positioned on the outside of the tubular element.

32. A method as claimed in any of claims 29, 30 or 31 , further comprising moving the apparatus with the expansion body longitudinally along the tubular element to progressively deform a length of the tubular element.

33. A method as claimed in any of claims 29, 30 or 31 , further comprising releasing the expansion body from compression such that it returns to its uncompressed shape, moving the tool body to another location in the tubular element and repeating expansion of the tubular element at the other location.

34. A method as claimed in any of claims 29 to 33, which further includes protecting the expansion body by a protective structure being located around at least a portion of the expansion body.

35. An apparatus for deforming the shape of tubular elements, comprising an expansion body that is compressible by travel through an area inside a tubular element, where the tubular element has an inner diameter which is less than the outer diameter of the expansion body when the expansion body is in its uncompressed state.

36. An apparatus as claimed in claim 35, wherein the expansion body is compressible by a device which applies force directly to the expansion body.