EP4223976A1

EP4223976A1 - Downhole expandable metal tubular

Info

Publication number: EP4223976A1
Application number: EP22155204.5A
Authority: EP
Inventors: Ricardo Reves Vasques
Original assignee: Welltec Oilfield Solutions AG
Current assignee: Welltec Oilfield Solutions AG
Priority date: 2022-02-04
Filing date: 2022-02-04
Publication date: 2023-08-09
Also published as: CN118434956A

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 intergral circumferential sealing element of metal as part of the outer face, providing the downhole expandable metal tubular with a first circumferential projection, and the at least one intergral 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.

Description

The present invention relates to a downhole expandable metal tubular to be expanded in a well downhole. Furthermore, the present invention relates to a patch and an annular barrier.
In wellbores, expandable metal tubulars are used for different purposes, such as for sealing off an opening in the casing, in the form of a patch or liner, for providing a barrier to flow between an inner and an outer tubular structure, or between an inner tubular structure and the inner wall of the borehole, in the form of an annular barrier, or for providing a liner hanger.
When the expandable metal tubulars are being used to seal off e.g. an opening or a zone, separate sealing elements are often provided on an exterior face of the expandable metal tubular for enhancing the sealing properties. Conventional sealing elements are made of polymers and elastomeric materials which has shown to have insufficient sealing ability in high-temperature wells, such as geothermal wells, and therefore the sealing elements have been developed to be made of PTFE; however, PTFE has proven insufficient for sealing elements, as PTFE does not seem to have sufficient flexibility in high-temperature wells.
It is an object of the present invention to wholly or partly overcome the above disadvantages and drawbacks of the prior art. More specifically, it is an object to provide a downhole expandable metal tubular with enhanced sealing properties in wells having high temperature above 300 °C.
The above objects, together with numerous other objects, advantages and features, which will become evident from the below description, are accomplished by a solution in accordance with the present invention by 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 intergral circumferential sealing element of metal as part of the outer face, providing the downhole expandable metal tubular with a first circumferential projection, and the at least one intergral circumferential sealing element at least partly defines a cavity having an opening.
By having a downhole expandable metal tubular with sealing elements only of metal material, the downhole expandable metal tubular can be used in high temperature wells, in geothermal wells and in Carbon Capture Storage (CCS) applications. By having a downhole expandable metal tubular without any elements of material of other than metal materials, the downhole expandable metal tubular is not limited to temperature substantially below 300 °C.
Moreover, the at least one intergral circumferential sealing element of metal may form one monolitic whole with the downhole expandable metal tubular.
Further, the downhole expandable metal tubular may further comprise a resilient element of metal arranged in the cavity.
By having a resilient element of metal arranged in the cavity, the sealing elements are only of metal material and are also flexible and are able to be compressed during expansion and after decompression fill up the small gab occuring during relaxing of the metal when the pressure is decreased. Thus by having a flexible selaing element and resilinet element, the downhole expandable metal tubular can be used in all wells and especially in high temperature wells, in geothermal wells and in Carbon Capture Storage (CCS) applications.
Furthermore, the cavity and the opening may extend along at least part of the entire circumference.
In addition, the opening may face a first axial direction parallel to the axial extension.
Also, the cavity is closed in a radial direction perpendicular to the axial extension.
Further, in a cross-sectional view of the downhole expandable metal tubular along the axial extension, the opening may have a first height in a radial direction perpendicular to the axial extionsion, the cavity having a second height in a radial direction perpendicular to the axial extionsion, the first height being smaller than the second height.
Additionally, in a cross-sectional view of the downhole expandable metal tubular along the axial extension, the intergral circumferential sealing element may have a C-shape, U-shape or similar shape.
Moreover, the downhole expandable metal tubular may further comprise a spacing element having a third height being smaller than a fourth height of the sealing element.
The spacing element prevents the sealing element from being squeezed too much for it to function properly and thus prevents it from permanently deforming. In this way, the spacing element ensures that the flexibility of the sealing element and the resilient element is maintained intact during expansion of the downhole expandable metal tubular.
In addition, the third height may be smaller than the second heigth.
Furthermore, the spacing element may be part of the sealing element or may be arranged distally from the sealing element along the axial extension.
The downhole expandable metal tubular may further comprise a resilient element arranged in the cavity.
Additionally, the spacing element may have a higher Youngs Modulus than that of the sealing element and/or the resilient element.
Also, the spacing element may be arranged in a first axial distance from the sealing element, the first axial distance being equal to or larger than an axial extension of the resilient element.
Further, the spacing element may be arranged in a position facing away from the opening.
The downhole expandable metal tubular may further comprise a resilient element arranged in the cavity, the resilient element having a fifth height being larger than the first height.
Furthermore, the resilient element may be made of metal.
By having a downhole expandable metal tubular of metal with an intergral circumferential sealing element of metal and a resilient element made of metal, the sealing element is fully of metal and comprise no other materials than metal and is therefore able to withstand very high temperatures, such as above 350 °Celsius.
In addition, the downhole expandable metal tubular being made completely of metal material.
By having a downhole expandable metal tubular fully of metal material, the downhole expandable metal tubular can be used in high temperature wells, in geothermal wells and in Carbon Capture Storage (CCS) applications. By having a downhole expandable metal tubular without any elements of material of other than metal materials, the downhole expandable metal tubular is not limited to temperature substantially below 300 °C.
Additionally, the material of the resilient element may have a lower Youngs Modulus than that of the material of the sealing element.
Furthermore, the resilient element may be a coiled spring. The resilient element may be a circumferential resilient element extending along the circumference of the outer face of the downhole expandable metal tubular.
Further, the intergral circumferential sealing element may comprise a projecting flange forming the cavity.
Moreover, the projecting flange forming the cavity overlaps at least one resiliant element along the axial extenxion.
In addition, the downhole expandable metal tubular may further comprise a second intergral circumferential sealing element of metal as part of the outer face, the second intergral 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.
Also, the second intergral circumferential sealing element may comprise a resilient element.
Moreover, the resilient element may have an outer volume that is smaller than an inner volume of the cavity.
Further, the intergral circumferential sealing element comprises at least two resilient elements.
The present invention also relates to a downhole expandable metal tubular assembly comprising a plurality of downhole expandable metal tubulars, wherein one of the downhole expandable metal tubulars is joined to another of the downhole expandable metal tubulars.
The expandable metal tubular assembly may according to the present invention also be joined by welding.
Furthermore, the expandable metal tubular assembly may be joined by electron beam welding.
Additionally, the downhole expandable metal tubular assembly may further comprise at least one end tubular, wherein the end tubular is configured to expand at a higher pressure than the downhole expandable metal tubulars.
The present invention also relates to 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 or the downhole expandable metal tubular assembly.
Finally, the present invention also relates to 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 or a downhole expandable metal tubular assembly, surrounding the tubular metal part and having an outer tubular face facing towards the 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 expansion space between the downhole expandable metal tubular/the downhole expandable metal tubular assembly and the tubular metal part.

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:

Fig. 1 is a cross-sectional view of a downhole expandable metal tubular,
Fig. 2 is a cross-sectional view of a downhole expandable metal tubular assembly,
Fig. 3 is a cross-sectional view of another downhole expandable metal tubular,
Fig. 4 is a cross-sectional view of a part of a downhole expandable metal tubular with an integral circumferential sealing element,
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,
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 elements,
Fig. 7 is a cross-sectional view of a part of a downhole expandable metal tubular with another integral circumferential sealing element,
Fig. 8 is a cross-sectional view of a part of a downhole expandable metal tubular with another integral circumferential sealing element, and
Fig. 9 is a cross-sectional view of an annular barrier.

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.
Fig. 1 shows a downhole expandable metal tubular 1 to be expanded in a well from a first outer diameter OD₁ to a second outer diameter OD₂ to abut against an inner face 41 of a casing 43 (shown in Fig. 2) or borehole 42. The expanded condition of the downhole expandable metal tubular is indicated by a dotted line. The downhole expandable metal tubular having 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 a casing or 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 or 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 a casing downhole for providing zone isolation between a first zone 101 and a second zone 102 of the borehole.
The downhole expandable metal tubular 1 is of metal with at least one first intergral circumferential sealing element 4 of metal as part of the outer face, so that the first intergral circumferential sealing element 4 provides a first circumferential projection 5 of the downhole expandable metal tubular 1. The intergral circumferential sealing element 4 at least partly defines a cavity 6 having an opening 7. The at least one first intergral circumferential sealing element of metal forms one monolitic whole with the downhole expandable metal tubular. 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 D₁ that is parallel to the axial extension L. The cavity 6 is closed in a radial direction R perpendicular to the axial extension L.
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 intergral circumferential sealing element 4 as shown in Figs. 1 and 2. When seen in a cross-sectional view of the downhole expandable metal tubular along axial extension in Figs. 1, 2 and 4, the intergral circumferential sealing element has a C-shape, but in another embodiment the intergral circumferential sealing element has U-shape or similar shape able to maintain the resilient element in the cavity 6.
By having a downhole expandable metal tubular of metal with an intergral circumferential sealing element of metal and a resilient element made of metal, the sealing element is fully of metal and comprises no other materials than metal and is therefore able to withstand very high temperatures, such as above 350 °Celsius. By having a downhole expandable metal tubular fully of metal material, the downhole expandable metal tubular can be used in high temperature wells, in geothermal wells and in Carbon Capture Storage (CCS) applications. By having a downhole expandable metal tubular without any elements of material of other than metal materials, the downhole expandable metal tubular is not limited to temperature substantially below 300 °C.
As shown, the intergral circumferential sealing element 4 comprises a projecting flange 14 forming the cavity. The projecting flange 14 forms the cavity 6 and overlaps at least one resiliant element 9 along the axial extenxion.
In Fig. 2, the downhole expandable metal tubular 1 further comprises a spacing element 8 arranged between two intergral circumferential sealing element. The spacing element is arranged in a first axial distance d₁ from the sealing element along the axial extension, and the first axial distance being equal to or larger than an axial extension of the resilient element. By the first axial distance being equal to or larger than an axial extension of the resilient element, the resilient element can be mounted in the cavity after the downhole expandable metal tubular 1 is treated by e.g. annealing. If the resilient element was already in the cavity during such annealing process, the resilient element would lose some of its flexibility. The C-shape of the sealing element may be made after inserting the resilient element in the cavity by bending the "end of the C", i.e. the projecting part ending in the opening. As shown in Fig. 8, the spacing element may be part of the sealing element or, as shown in Figs. 2, 3 and 8, arranged distally from the sealing element along the axial extension. The spacing element 8 has a higher Youngs Modulus than that of the sealing element and/or the resilient element. 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. Fig. 3 shows downhole expandable metal tubular 1 with spacing elements 8 and sealing elements 4 formed as one monolithic whole.
In the cross-sectional view of part of the downhole expandable metal tubular along axial extension of Fig. 4, the opening 7 has a first height h₁ in a radial direction R (shown in Fig. 1) perpendicular to the axial extionsion, and the cavity 6 has a second height h₂ in the radial direction R perpendicular to the axial extionsion, where the first height is smaller than the second height.
As shown in Fig. 4, the downhole expandable metal tubular further comprises a resilient element 9 arranged in the cavity 6. When the downhole expandable metal tubular is expanded and the intergral circumferential sealing element is pressed against the inner face of the borehole or a 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 radially inwards, the compression of the resilient element is released and presses the sealing element radially outwards taking up the small gap occurring during the somewhat backwards movement of the downhole expandable metal tubular. The resilient element has a fifth height h₅ being larger than the first height. The resilient element is made of metal, and the resilient element may be a coiled spring. The material of the resilient element has a lower Youngs Modulus than that of the material of the sealing element. 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.
In Fig. 7, the spacing element 8 having a third height h₃ being smaller than a fourth height h₄, so that when the downhole expandable metal tubular is expanded and the intergral circumferential sealing element is pressed against the inner face of the borehole or a casing the spacing element 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 and the resilient element is maintained intact during expansion of the downhole expandable metal tubular. As shown, the third height may also be smaller than the second heigth h₂. In Figs. 7 and 8, the spacing element 8 is arranged in a position facing away from the opening 7.
In Figs. 5 and 6, the downhole expandable metal tubular further comprises a second intergral circumferential sealing element 10 of metal as part of the outer face. The second intergral circumferential sealing element 10 has an opening 11 facing a second axial direction D₂ along the axial extenxion, the second axial direction being opposite the first axial direction D₁. The second intergral circumferential sealing element comprises in the same way as the first intergral circumferential sealing element a cavity 6 and the opening 11 and a resilient element 9 arragned in the cavity. In Fig. 6, the intergral circumferential sealing elements 4, 10 comprise at least two resilient elements in order to further strengthen the sealing ability of the sealing elements 4, 10.
Fig. 9 discloses an annular barrier 30 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 101 and a second zone 102 of the borehole. The annular barrier comprises a tubular metal part 31 mounted as part of the well tubular metal structure 103. The annular barrier further comprises a downhole expandable metal tubular 1 or a downhole expandable metal tubular assembly 20 surrounding the tubular metal part and having an outer tubular face 32 facing towards the inner face 105 of the borehole or the casing. Each end 33 of the downhole expandable metal tubular/the downhole expandable metal tubular assembly being connected with the tubular metal part 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/the downhole expandable metal tubular assembly and the tubular metal part. In Fig. 9, the annular barrier 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 aperture 34 in the tubular metal part 31 into the valve assembly and further into the expandable space 35.
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.
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.
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.

Claims

A downhole expandable metal tubular (1) to be expanded in a well from a first outer diameter (OD₁) to a second outer diameter (OD₂) to abut against an inner face of a casing or borehole, the downhole expandable metal tubular having an axial extension (L), a circumference (C) and an outer face (3),
wherein the downhole expandable metal tubular is of metal with at least one first intergral circumferential sealing element (4) of metal as part of the outer face, providing the downhole expandable metal tubular with a first circumferential projection (5), and the at least one intergral circumferential sealing element at least partly defines a cavity (6) having an opening (7).
A downhole expandable metal tubular according to any of the preceding claims, further comprising a resilient element (9) of metal arranged in the cavity.
A downhole expandable metal tubular according to claim 1 or 2, wherein the cavity and the opening extend along at least part of the entire circumference.
A downhole expandable metal tubular according to any of the preceding claims, wherein the opening faces a first axial direction (D₁) parallel to the axial extension.
A downhole expandable metal tubular according to any of the preceding claims, wherein the cavity is closed in a radial direction (R) perpendicular to the axial extension.
A downhole expandable metal tubular according to any of the preceding claims, wherein in a cross-sectional view of the downhole expandable metal tubular along the axial extension, the opening has a first height (h₁) in a radial direction perpendicular to the axial extionsion, and the cavity has a second height (h₂) in a radial direction (R) perpendicular to the axial extionsion, the first height being smaller than the second height.
A downhole expandable metal tubular according to any of the preceding claims, further comprising a spacing element (8) having a third height (h₃) being smaller than a fourth height of the sealing element.
A downhole expandable metal tubular according to any of the preceding claims, wherein the spacing element may be part of the sealing element or may be arranged distally from the sealing element along the axial extension.
A downhole expandable metal tubular according to any of the preceding claims, wherein the spacing element has a higher Youngs Modulus than that of the sealing element and/or the resilient element.
A downhole expandable metal tubular according to any of the preceding claims, wherein the spacing element is arranged in a first axial distance (D₁) from the sealing element, the first axial distance being equal to or larger than an axial extension of the resilient element.
A downhole expandable metal tubular according to claims 1, 3-10, further comprising a resilient element (9) arranged in the cavity, the resilient element having a fifth height (h₅) being larger than the first height.
A downhole expandable metal tubular according to any of the preceding claims, further comprising a second intergral circumferential sealing element (10) of metal as part of the outer face, the second intergral circumferential sealing element having an opening (11) facing a second axial direction (d₂) along the axial extenxion, the second axial direction being opposite the first axial direction.
A downhole expandable metal tubular assembly (20) comprising a plurality of downhole expandable metal tubulars according to any of the preceding claims, wherein one of the downhole expandable metal tubulars is joined to another of the downhole expandable metal tubulars.
A downhole expandable metal tubular assembly (20) according to claim 13, further comprising at least one end tubular (12), wherein the end tubular is configured to expand at a higher pressure than the downhole expandable metal tubulars.
A patch (20) 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 any of the preceding claims 1-13 or the downhole expandable metal tubular assembly according to claim 13 or 14.
An annular barrier (30) 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 (101) and a second zone (102) of the borehole, comprising:
- a tubular metal part (31) for mounting as part of the well tubular metal structure,

- a downhole expandable metal tubular (1) according to any of claims 1-13 or a downhole expandable metal tubular assembly (20) according to claim 143 or 14, surrounding the tubular metal part and having an outer tubular face (32) facing towards the inner face (105) 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 (35) between the downhole expandable metal tubular/the downhole expandable metal tubular assembly and the tubular metal part.