DOWNHOLE EXPANDABLE METAL TUBULAR

Abstract

The present invention relates to a downhole expandable metal tubular to be expanded in a well from a first outer diameter to a second outer diameter to abut against an inner face of a casing or borehole, the downhole expandable metal tubular having an axial extension, a circumference and an outer face, wherein the downhole expandable metal tubular is of metal with at least one first integral circumferential sealing element of metal as part of the outer face, providing the downhole expandable metal tubular with a first circumferential projection having a fourth height, and the at least one first integral circumferential sealing element at least partly defines a cavity having an opening. Moreover, the present invention also relates to a downhole expandable metal tubular assembly further comprising at least one end tubular, a patch for being expanded within a well tubular metal structure for sealing off leaks, perforations or apertures in the well tubular metal structure, and an annular barrier to be expanded in an annulus between a well tubular structure and an inner face of a borehole or a casing downhole for providing zone isolation between a first zone and a second zone of the borehole.

Claims

1. A downhole expandable metal tubular to be expanded in a well from a first outer diameter to a second outer diameter to abut against an inner face of a casing or borehole, the downhole expandable metal tubular having an axial extension, a circumference and an outer face, wherein the downhole expandable metal tubular is of metal with at least one first integral circumferential sealing element of metal as part of the outer face, providing the downhole expandable metal tubular with a first circumferential projection having a fourth height, and the at least one first integral circumferential sealing element at least partly defines a cavity having an opening.

2. A downhole expandable metal tubular according to claim 1, further comprising a resilient element of metal arranged in the cavity.

3. A downhole expandable metal tubular according to claim 1, wherein the cavity and the opening extend along at least part of the entire circumference.

4. A downhole expandable metal tubular according to claim 1, wherein the opening faces a first axial direction parallel to the axial extension.

5. A downhole expandable metal tubular according to claim 1, wherein, in a cross-sectional view of the downhole expandable metal tubular along the axial extension, the opening has a first height in a radial direction perpendicular to the axial extension, and the cavity has a second height in a radial direction perpendicular to the axial extension, the first height being smaller than the second height.

6. A downhole expandable metal tubular according to claim 1, wherein, in a cross-sectional view of the downhole expandable metal tubular along the axial extension, the at least one first integral circumferential sealing element has the fourth height in a radial direction perpendicular to the axial extension, the opening has a first height in the radial direction, the first height being smaller than the fourth height.

7. A downhole expandable metal tubular according to claim 1, further comprising a spacing element having a third height being smaller than a fourth height of the at least one first integral circumferential sealing element.

8. A downhole expandable metal tubular according to claim 1, wherein the spacing element may be part of the at least one first integral circumferential sealing element or may be arranged distally from the at least one first integral circumferential sealing element along the axial extension.

9. A downhole expandable metal tubular according to claim 1, wherein the spacing element has a higher Young's Modulus than that of the at least one first integral circumferential sealing element and/or the resilient element.

10. A downhole expandable metal tubular according to claim 1, wherein the spacing element is arranged in a first axial distance from the at least one first integral circumferential sealing element, the first axial distance being equal to or larger than an axial extension of the resilient element.

11. A downhole expandable metal tubular according to claim 1, further comprising a resilient element arranged in the cavity, the resilient element having a fifth height being larger than the first height.

12. A downhole expandable metal tubular according to claim 1, further comprising a second integral circumferential sealing element of metal as part of the outer face, the second integral circumferential sealing element having an opening facing a second axial direction along the axial extenxion, the second axial direction being opposite the first axial direction.

13. A downhole expandable metal tubular assembly comprising a plurality of downhole expandable metal tubulars according to claim 1, wherein one of the downhole expandable metal tubulars is joined to another of the downhole expandable metal tubulars.

14. A downhole expandable metal tubular assembly according to claim 13, further comprising at least one end tubular, wherein the end tubular is configured to expand at a higher pressure than the downhole expandable metal tubulars.

15. A patch for being expanded within a well tubular metal structure for sealing off leaks, perforations or apertures in the well tubular metal structure, wherein the patch is the downhole expandable metal tubular according to claim 13 or the downhole expandable metal tubular assembly.

16. An annular barrier to be expanded in an annulus between a well tubular structure and an inner face of a borehole or a casing downhole for providing zone isolation between a first zone and a second zone of the borehole, comprising: a tubular metal part for mounting as part of the well tubular metal structure, a downhole expandable metal tubular according to claim 1 or a downhole expandable metal tubular assembly surrounding the tubular metal part and having an outer tubular face facing towards an inner face of the borehole or the casing, each end of the downhole expandable metal tubular/the downhole expandable metal tubular assembly being connected with the tubular metal part, and an expandable space between the downhole expandable metal tubular/the downhole expandable metal tubular assembly and the tubular metal part.

Description

[0063] The invention and its many advantages will be described in more detail below with reference to the accompanying schematic drawings, which for the purpose of illustration show some non-limiting embodiments and in which:

[0064] FIG. 1 is a cross-sectional view of a downhole expandable metal tubular,

[0065] FIG. 2 is a cross-sectional view of a downhole expandable metal tubular assembly,

[0066] FIG. 3 is a cross-sectional view of another downhole expandable metal tubular,

[0067] FIG. 4 is a cross-sectional view of a part of a downhole expandable metal tubular with an integral circumferential sealing element,

[0068] FIG. 5 is a cross-sectional view of a part of a downhole expandable metal tubular with a first integral circumferential sealing element and a second integral circumferential sealing element,

[0069] FIG. 6 is a cross-sectional view of a part of a downhole expandable metal tubular with another first integral circumferential sealing element and another second integral circumferential sealing element,

[0070] FIG. 7 is a cross-sectional view of a part of a downhole expandable metal tubular with another integral circumferential sealing element,

[0071] FIG. 8 is a cross-sectional view of a part of a downhole expandable metal tubular with another integral circumferential sealing element, and

[0072] FIG. 9 is a cross-sectional view of an annular barrier.

[0073] All the figures are highly schematic and not necessarily to scale, and they show only those parts which are necessary in order to elucidate the invention, other parts being omitted or merely suggested.

[0074] FIG. 1 shows a downhole expandable metal tubular 1 to be expanded in a well from a first outer diameter OD.sub.1 to a second outer diameter OD.sub.2 to abut against an inner face 41 of a casing 43 (shown in FIG. 2) or a borehole 42. The expanded condition of the downhole expandable metal tubular 1 is indicated by a dotted line. The downhole expandable metal tubular 1 has an axial extension L, a circumference C and an outer face 3. The downhole expandable metal tubular 1 may form a patch 20 to be expanded within the casing 43 or a well tubular structure in a well. The downhole expandable metal tubular 1 may also be a liner hanger 21 to be at least partly expanded within the casing 43 or a well tubular structure in the well. The downhole expandable metal tubular 1 may also form part of an annular barrier 30 (shown in FIG. 9) to be expanded in an annulus 104 between a well tubular structure and an inner face 105 of a borehole 106 or the casing 43 downhole for providing zone isolation between a first zone 101 and a second zone 102 of the borehole.

[0075] The downhole expandable metal tubular 1 is of metal with at least one first integral circumferential sealing element 4 of metal as part of the outer face 3, so that the first integral circumferential sealing element 4 provides a first circumferential projection 5 of the downhole expandable metal tubular 1. The integral circumferential sealing element 4 at least partly defines a cavity 6 having an opening 7. The at least one first integral circumferential sealing element 4 of metal forms one monolitic whole with the downhole expandable metal tubular 1. The cavity 6 and the opening 7 extend along at least part of the entire circumference C. The opening 7 faces a first axial direction D.sub.1 that is parallel to the axial extension L. The cavity 6 is closed in a radial direction R perpendicular to the axial extension L.

[0076] The downhole expandable metal tubular 1 further comprises a plurality of resilient elements 9 of metal, where one resilient element 9 is arranged in the cavity 6 of the integral circumferential sealing element 4 as shown in FIGS. 1 and 2. When seen in a cross-sectional view of the downhole expandable metal tubular 1 along the axial extension L in FIGS. 1, 2 and 4, the integral circumferential sealing element 4 has a C-shape, but in another embodiment the integral circumferential sealing element has a U-shape or a similar shape able to maintain the resilient element in the cavity 6.

[0077] By having a downhole expandable metal tubular 1 of metal with an integral circumferential sealing element 4 of metal and a resilient element 9 made of metal, the sealing element is made fully of metal and comprises no other materials than metal, and the sealing element is therefore able to withstand very high temperatures, such as above 350° C. By having a downhole expandable metal tubular 1 made fully of metal material, the downhole expandable metal tubular 1 can be used in high-temperature wells, in geothermal wells and in Carbon Capture Storage (CCS) applications. By having a downhole expandable metal tubular 1 without any elements of material other than metal materials, the downhole expandable metal tubular is not limited to temperatures substantially below 300° C.

[0078] As shown, the integral circumferential sealing element 4 comprises a projecting flange 14 forming the cavity 6. The projecting flange 14 forms the cavity 6 and overlaps at least one resilient element 9 along the axial extenxion L.

[0079] In FIG. 2, the downhole expandable metal tubular 1 further comprises a spacing element 8 arranged between two integral circumferential sealing elements 4. The spacing element 8 is arranged in a first axial distance di from the sealing element 4 along the axial extension L, the first axial distance being equal to or larger than the axial extension of the resilient element 9. As a result of the first axial distance d.sub.1 being equal to or larger than the axial extension L of the resilient element 9, the resilient element can be mounted in the cavity 6 after the downhole expandable metal tubular 1 is treated by e.g. annealing. If the resilient element 9 was already in the cavity 6 during such annealing process, the resilient element would lose some of its flexibility. The C-shape of the sealing element 4 may be made after inserting the resilient element 9 in the cavity 6 by bending the “end of the C”, i.e. the projecting part ending in the opening. As shown in FIG. 8, the spacing element 8 may be part of the sealing element 4 or, as shown in FIGS. 2, 3 and 8, arranged distally from the sealing element along the axial extension L. The spacing element 8 has a higher Young's Modulus than that of the sealing element 4 and/or the resilient element 9. FIG. 2 shows a downhole expandable metal tubular assembly 20 comprising a plurality of downhole expandable metal tubulars 1, where one of the downhole expandable metal tubulars 1 is joined to another of the downhole expandable metal tubulars 1. The downhole expandable metal tubulars 1 are joined by welding, e.g. electron beam welding. The spacing element 8 may be added also by means of welding by adding further material on the weld seam. The downhole expandable metal tubular 1 further comprises an end tubular 12 in each end, and the end tubulars are configured to expand at a higher pressure than the downhole expandable metal tubulars 1. FIG. 3 shows the downhole expandable metal tubular 1 with the spacing elements 8 and the sealing elements 4 formed as one monolithic whole.

[0080] In the cross-sectional view of part of the downhole expandable metal tubular 1 along the axial extension L of FIG. 4, the opening 7 has a first height h.sub.1 in the radial direction R (shown in FIG. 1) perpendicular to the axial extension L, and the cavity 6 has a second height h.sub.2 in the radial direction R perpendicular to the axial extension, where the first height is smaller than the second height.

[0081] As shown in FIG. 4, the downhole expandable metal tubular 1 further comprises the resilient element 9 arranged in the cavity 6. When the downhole expandable metal tubular 1 is expanded, and the integral circumferential sealing element 4 is pressed against the inner face of the borehole or the casing, the resilient element 9 is compressed. Subsequently, when the expansion is over and the pressure is decreased, the downhole expandable metal tubular 1 flexes somewhat backwards and radially inwards, the compression of the resilient element 9 is released and presses the sealing element 4 radially outwards, taking up the small gap occurring during the somewhat backwards movement of the downhole expandable metal tubular. The resilient element 9 has a fifth height h.sub.5 being larger than the first height h.sub.1. The resilient element 9 is made of metal, and the resilient element may be a coiled spring. The material of the resilient element 9 has a lower Young's Modulus than that of the material of the sealing element 4. As can be seen in FIG. 4, the resilient element 9 has an outer volume that is smaller than an inner volume of the cavity 6.

[0082] In FIG. 7, the spacing element 8 has a third height h.sub.3 being smaller than a fourth height h.sub.4, so that when the downhole expandable metal tubular 1 is expanded and the integral circumferential sealing element 4 is pressed against the inner face of the borehole or a casing, the spacing element 8 prevents the sealing element from being squeezed too much and prevents it from permanently deforming. In this way, the spacing element 8 ensures that the flexibility of the sealing element 4 and the resilient element 9 is maintained intact during expansion of the downhole expandable metal tubular 1. As shown, the third height h.sub.3 may also be smaller than the second heigth h.sub.2. In FIGS. 7 and 8, the spacing element 8 is arranged in a position facing away from the opening 7.

[0083] In FIGS. 5 and 6, the downhole expandable metal tubular 1 further comprises a second integral circumferential sealing element 10 of metal as part of the outer face. The second integral circumferential sealing element 10 has an opening 11 facing a second axial direction D.sub.2 along the axial extenxion L, the second axial direction being opposite the first axial direction D.sub.1. The second integral circumferential sealing element 10 comprises, in the same way as the first integral circumferential sealing element 4, the cavity 6 and the opening 11 as well as the resilient element 9 arranged in the cavity. In FIG. 6, the integral circumferential sealing elements 4, 10 comprise at least two resilient elements 9 in order to further strengthen the sealing ability of the sealing elements 4, 10.

[0084] FIG. 9 discloses an annular barrier 30 to be expanded in an annulus between a well tubular structure and an inner face of the borehole 106 or the casing downhole for providing zone isolation between the first zone 101 and the second zone 102 of the borehole. The annular barrier 30 comprises a tubular metal part 31 mounted as part of a well tubular metal structure 103. The annular barrier 30 further comprises the downhole expandable metal tubular 1 or the downhole expandable metal tubular assembly 20 surrounding the tubular metal part 31 and having an outer tubular face 32 facing towards the inner face 105 of the borehole 106 or the casing. Each end 33 of the downhole expandable metal tubular 1/the downhole expandable metal tubular assembly 20 being connected with the tubular metal part 31 by a connection part 36 and a valve assembly may be attached to one of the connection parts. An expansion/expandable space 35 is formed between the downhole expandable metal tubular 1/the downhole expandable metal tubular assembly 20 and the tubular metal part 31. In FIG. 9, the annular barrier 30 is shown in its unexpanded condition, and the expanded condition is illustrated by a dotted line and occurs when the well tubular metal structure 103 is pressurised from within, and fluid enters through an aperture 34 in the tubular metal part 31 into the valve assembly and further into the expandable space 35.

[0085] By “fluid” or “well fluid” is meant any kind of fluid that may be present in oil or gas wells downhole, such as natural gas, oil, oil mud, crude oil, water, etc. By “gas” is meant any kind of gas composition present in a well, completion or open hole, and by “oil” is meant any kind of oil composition, such as crude oil, an oil-containing fluid, etc. Gas, oil and water fluids may thus all comprise other elements or substances than gas, oil and/or water, respectively.

[0086] By “casing”, “well tubular structure” or “well tubular metal structure” is meant any kind of pipe, tubing, tubular, liner, string, etc., used downhole in relation to oil or natural gas production.

[0087] Although the invention has been described above in connection with preferred embodiments of the invention, it will be evident to a person skilled in the art that several modifications are conceivable without departing from the invention as defined by the following claims.