Monobore expansion system - Anchored liner

Abstract

Method for lining a borehole (12) comprising: Placing a first liner (54) in the borehole (12), wherein the first liner (54) has a lower section, Placing a second liner (52) in the borehole (12), wherein an upper section of the second liner (52) is placed in the lower section of the first liner (54), Positioning an upper sealing element (90) and a lower sealing element (80) in the borehole (12) to form a pressure chamber (100), wherein the upper sealing element (90) and the lower sealing element (80) move axially away from each other, the axial movement causing the working string (18) to move upwards and pull an expansion device (60) through a bore (82) of the second liner (52), Expanding the second liner (52) using the pressure chamber (100) and Positioning the upper sealing element (90) and the lower sealing element (80) in the first liner (54) and over the second liner (52), thereby hydraulically isolating an inner bore (82) of the second liner (52) from the pressure chamber (100).

Description

BACKGROUND OF THE REVELATION 1. Technical Field

[0001] The present invention relates generally to oilfield well drilling tools. In particular, the present invention relates to methods for lining a well and to a device for positioning a first liner and a second liner in a well. 2. Description of the state of the art

[0002] Hydrocarbons, such as oil and gas, as well as geothermal resources, are extracted from an underground formation using a wellbore drilled into the formation. Such wellbores are typically completed by placing a casing along the length of the wellbore, with the annular space between the casing and the wellbore cemented and the casing perforated adjacent to each production zone. A wellbore casing is often constructed by joining relatively short sections of pipe (for example, 10 m long) via threaded connections at the pipe ends. Such conventional casing techniques use pipe strings with decreasing diameters and incorporate multiple threaded connections. Monowell construction, which employs a solid casing structure, has limitations regarding the achievable resistance to the collapse of an extended pipe.When threaded liner elements expand, there is a risk to their long-term durability. The cost of constructing deep boreholes with extended reach is very high. Therefore, it is desirable to provide alternative methods for constructing such boreholes.

[0003] Expansion devices coupled to a working string and designed to expand a pipe section are known from US Patents 7,090,025 B2 and 6,843,322 B2. US Patent 8,020,625 B2 further discloses the use of two expansion devices that can be operated independently. A first, upper expansion device is designed to expand a first pipe section so that it comes into contact with a tube surrounding it. A second, lower expansion device is designed to expand a second pipe section located outside the surrounding tube. BRIEF SUMMARY

[0004] In some aspects, the present disclosure provides a method for lining a borehole.The method may include placing a first liner with a lower section in the borehole, placing a second liner in the borehole, wherein an upper section of the second liner is placed in the lower section of the first liner, positioning an upper sealing element and a lower sealing element in the borehole to form a pressure chamber, wherein the upper sealing element and the lower sealing element move axially away from each other, the axial movement causing the working string to move upwards and pull an expansion device through a bore of the second liner, expanding the second liner using the pressure chamber, and positioning the upper sealing element and the lower sealing element in the first liner and above the second liner, thereby hydraulically isolating an inner bore of the second liner from the pressure chamber.

[0005] In some aspects, the present disclosure also provides a device for positioning a first liner and a second liner in a borehole. The second liner can have an upper section that is placed in a lower section of the first liner. The device can have at least one upper sealing element and at least one lower sealing element that interacts with the at least one upper sealing element to form a pressure chamber that is hydraulically isolated from an internal bore of the second liner, wherein the at least one upper sealing element and the at least one lower sealing element are positioned in the first liner and above the second liner. The at least one upper sealing element and the at least one lower sealing element are configured such that they separate axially in response to pressure in the pressure chamber.The device further comprises a working string configured to transport the at least one upper sealing element and the at least one lower sealing element into the borehole, wherein the axial movement causes the working string to move upwards and draw an expansion device through a bore of the second liner, at least one connector connected to the working string and extending through the pressure chamber and the second liner, and the expansion device connected to the connector, wherein the expansion device is configured to expand the second liner in response to the axial separation of the at least one upper sealing element and the at least one lower sealing element. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] For a detailed understanding of the present disclosure, reference should be made to the following detailed description of the preferred embodiment in conjunction with the accompanying drawings, in which identical elements have been provided with the same reference numerals and in which Fig. 1 shows a drilling rig for completing a borehole using a liner system according to an embodiment of the present disclosure, Fig. 2 shows a liner system positioned in the borehole according to an embodiment of the present disclosure, Fig. 3 shows a folded liner system according to an embodiment of the present disclosure, Fig. 4 shows a liner system inserted into the borehole according to an embodiment of the present disclosure, Fig. 5 shows a pressure chamber according to an embodiment of the present disclosure, which is activated by fluid pumped down from the surface, Fig. Figure 6 shows an expansion device drawn into a liner according to an embodiment of the present disclosure, Fig. 7 shows the expansion device extending the liner according to an embodiment of the present disclosure, Fig. 8 showing an expansion device extending a liner shoe into engagement with a borehole wall according to an embodiment of the present disclosure, Fig. Figure 9 shows an anchor deactivated to reduce tensile stress in the extended liner according to an embodiment of the present disclosure, Fig. 10 shows the expansion device entering an overlap area between the liner and a mother liner according to an embodiment of the present disclosure, Fig. 11 shows the anchor separated from the liner according to an embodiment of the present disclosure, Fig. 12 shows the expansion device, which has collapsed to a design with a reduced diameter, according to an embodiment of the present disclosure, Fig. 13 shows the expansion device according to an embodiment of the present disclosure, which continues the movement through the liner and the expansion of the liner, Fig. 14 shows a fully extended liner, and Fig. Figure 15 shows a bypass that allows a fluid flow over the liner assembly while the liner assembly is being removed from the borehole. DETAILED DESCRIPTION

[0007] This disclosure relates to monobore boreholes that use overlapping expandable liners to casing the borehole. This disclosure is suitable for various configurations. Exemplary embodiments of this disclosure are shown in the drawings and described in detail here, with the understanding that this disclosure is to be regarded as an explanation of the principles of the disclosure and is not intended to limit the disclosure of what is shown and described herein.

[0008] First on Fig. With reference to Figure 1, a system 10 for carrying out a borehole-related operation, such as completing a borehole 12 drilled into a formation 14, is shown. The system 10 has a drilling rig 16 at the surface for erecting a working string 18. The working string 18 can convey a liner completion system 50 for lining the borehole 12 with borehole casing. The casing can be a liner, casing, wound pipe, rigid pipe, or other casing designed to be expanded and secured in the borehole 12. The borehole 12 can be intended for the extraction of hydrocarbons, such as oil and gas, as well as for access to geothermal resources. The drilling rig 16 can include devices such as an injector 20 for conveying the working string 18 into and out of the borehole 12 and a pump 22.It is understood that the injector 20 and the pump 22 merely illustrate the types of equipment that may be used in conjunction with the borehole operations described below.

[0009] Now, referring to Fig. Figure 2 shows an embodiment of a liner system 50 that can be used to connect a liner 52 to a mother liner 54. The liner system 50 can include an expansion device 60 for expanding the liner 52, an anchor 70 that selectively anchors the liner 52 to the mother liner 54, and a lower sealing element 80 and an upper sealing element 90 that form a pressure chamber 100 outside the liner 52. The upper and lower sealing elements 80, 90 are both positioned in the borehole 12 rather than at the surface (which may be a seabed). Therefore, unlike surface or seabed equipment such as wellheads, submerged wellheads, risers, and well shut-off valves, the sealing elements 80, 90 are dimensioned and shaped such that they can be transported along the borehole 12 using the working string 18.

[0010] Now, referring to Fig. 3. The liner 52 can be configured as an expandable piping with a two-pole folding geometry. The liner 52 can have a non-circular, non-expanded geometry, resulting in a smaller effective diameter than when the liner 52 is fully expanded. The liner 52 can be expanded by pulling the expansion device 60 ( Fig. 2) are extended through the passage 56. In one embodiment, the liner 52 is extended from an initially non-circular shape to an intermediate circular shape and then to a circular shape with a larger diameter. In another embodiment, the liner 52 is initially circular and is extended to a larger diameter.

[0011] The working strand 18 can be designed to pull the expansion device 60 through the passage 56. In one embodiment, the working strand 18 can have a coupling 92 that connects one or more connectors 94 to the expansion device 60. Advantageously, a coiled tube is used as an exemplary working strand, but it is understood that any rigid or non-rigid element can also be used as a working strand.

[0012] The connectors 94 can be rods, tubes, poles, or other similar elongated elements that connect the expansion device 60 to the working string 18. The connectors 94 can be designed to lie within the passage 56 and transmit at least tensile stress forces in the working string 18 to the expansion device 60. The connectors 94 can be rigid (e.g., steel rods) or non-rigid (e.g., steel cables). While two connectors 94 are shown, it is understood that a larger or smaller number of connecting elements can be used.

[0013] The upper sealing element 90 can be attached to the working strand 18 and configured to selectively form a fluid barrier over an annular space 93 between the working strand 18 and an inner diameter of the mother liner(s) 54. While two upper sealing elements 90 are shown, it is understood that a smaller or larger number of sealing elements can be distributed in series along the working strand 18.

[0014] The lower sealing element 80 selectively forms a fluid barrier that prevents the fluid pressure in the bore 82 from increasing the fluid pressure in the liner 52. Consequently, the lower sealing element 80 hydraulically isolates the interior of the liner 52 from the pressure upstream of the lower sealing element 80. The lower sealing element 80 can have one or more dynamic seals 84 that allow the connector(s) 94 to slide axially while maintaining a sealing barrier over the bore 82. In some embodiments, the dynamic seals 84 can be independent of the lower sealing element 80 in structure and function. The lower sealing element 80 can also have an opening 86 that allows a fluid connection between a bore 56 of the liner 52 and the annular space 88.

[0015] The sealing elements 80, 90 can have a cup-shaped, flexible sealing element that provides direction-sensitive sealing functionality (e.g., swab cups). This means the sealing elements can be chamfered to allow the formation of a seal when the pressure increases either downstream or upstream of the borehole. In one arrangement, the sealing element of the upper sealing element 92 can be chamfered downwards, so that an increase in pressure downstream of the borehole activates the sealing function. Similarly, the sealing element of the lower sealing element 92 can be chamfered upwards, so that an increase in pressure upstream of the borehole activates the sealing function. Consequently, the opposing chamfered sealing elements of the sealing elements 80, 90 work together to form a sealed environment for the pressure chamber 100 located between the sealing elements 80, 90.

[0016] In such arrangements, the upper sealing element 92 is deactivated when it is conveyed upwards through the hole, and the lower sealing element 92 is deactivated when it is conveyed downwards through the hole. Deactivated means that fluid flow over the sealing elements 80 and 90 is permitted. As discussed below, bypasses and valves can be used to reduce surge and / or swab effects when the upper sealing element 92 is conveyed downwards through the hole and the lower sealing element 92 is conveyed upwards through the hole.

[0017] The anchor 70 is attached to an upper end of the liner 52 and selectively connects the liner 52 to the mother liner 54. As discussed above, the sealing elements 80, 90 form fluid-tight barriers that create a pressure chamber 100. When the pressure in the pressure chamber 100 reaches a predetermined value, the anchor 70 extends into an anchoring engagement with the liner 54. The pressure chamber 100 can be pressurized by the use of fluids supplied by a pump 22 ( Fig. 1) are pumped down from the surface via the working strand 18 and pressurized. Consequently, the armature 70 is activated / actuated by applying pressure in the pressure chamber 100. Suitable non-limiting devices for the armature 70 include radially extendable slides, pads, and levers.

[0018] The expansion device 60 can be a die-cast device connected to a lower end of the connectors 94 and has a diameter or diameters selected to expand the liner 52 to a desired diameter. In one embodiment, the expansion device 60 can have an upper cone 62 and a lower cone 64. The cones 62, 64 can be made of rigid materials. A locking element 58 can be used to connect the expansion device 60 to a lower end of the liner 52. The locking element 58 can be a shear bolt or another device calibrated to decouple the expansion device 60 from the liner 52 under a predetermined condition (e.g., a selected tensile stress force). One or both cones 62, 64 can also be collapsible.In an umbrella-like embodiment, the cones 62, 64 can be fixed in an enlarged configuration during the expansion process. Subsequently, a device such as a shear bolt or locking mechanism is activated (e.g., snapped into place or broken) to allow the cones 62, 64 to collapse into a configuration with smaller dimensions.

[0019] Now, with reference to Fig. 4-15 describes the use of the liner system 50 for lining a borehole 12. Fig. Figure 4 shows the system 50 after it has been "driven" into borehole 12. Borehole 12 is typically filled with fluids. Therefore, the fluids under the liner system 50 can encounter a surge wave as the liner system 50 traverses borehole 12. Since the lower sealing element 80 is carried down the borehole, its sealing function is deactivated due to the upward-sloping design of the sealing element. Consequently, fluids flow down the borehole of the liner system 50 to the opening 102 and to a bore 104 of the working string 18 at the coupling 92, thereby reducing surge effects.

[0020] Now, referring to Fig. Figure 5 shows the liner system 50 positioned at a distal end of the mother liner 54. Fluid pumped downwards through bore 104 exits at opening 102 and flows into pressure chamber 100. When the pressure in pressure chamber 100 reaches a predetermined value, the lower sealing element 80 moves and engages the anchor 70. Responding to this, the anchor 70 expands the liner 52 and anchors it to the mother liner 54. It is understood that other activation arrangements utilizing pressure in pressure chamber 100 can also be used to supply energy to and activate the anchor 70. For example, the pressure in pressure chamber 100 can be used by a piston-cylinder system to engage ramps or sliding elements that drive the anchor elements of the anchor 52 radially outwards into engagement with the mother liner 54.

[0021] Now, referring to Fig. 6, when more fluid is pumped into the pressure chamber 100, the increased pressure applied to the upper sealing element 90 drives the working string 18 in an upward direction. Consequently, the upper and lower sealing elements 90, 80 separate axially, since the lower sealing element 80 is stationary and the upper sealing element 90 moves upward. Because the expansion device 60 is rigidly connected to the working string 18 by the connectors 94, the expansion device 60 is also pulled in the upward direction and into the liner 52. Once the tensile force is sufficient to break or dislodge the locking element 68, the expansion device 60 engages and expands the liner 52.In embodiments in which the expansion device 60 has a first cone 62 and a second cone 64, the first cone 62 can expand the liner 52 to a first diameter and the second cone 64 can expand the liner 52 to a second larger diameter.

[0022] The axial movement of the expansion device 60 through the liner 52 can induce an axial load on the liner 52. These loads can be controlled by selectively anchoring the upper end 53 and the lower end 55 of the liner 52 during expansion. As shown in Fig. As shown in Figure 6, the lower end 55 is not anchored to the borehole wall 108, and the upper end 53 is anchored to the mother liner 54. Therefore, the axial upward movement of the expansion device 60 can cause a compressive load in the liner 52, which can lead to buckling. In one variant, the lower end 53 of the liner 52 can be anchored to the borehole wall 108 upstream of the expansion device 60 using a suitable anchor 105. The anchor 105 can be any device having pads, ribs, slides, pins, or other suitable anchoring elements that extend radially outward and engage in the borehole wall 108. The drive or actuating device (not shown) for driving the anchoring elements into the borehole wall 108 can be powered by pressurized fluids, electric current, or any other energy source that may be located on the surface or in the borehole.The anchor 105 absorbs the axial load during extension, thereby reducing the likelihood of buckling. It should be noted that the liner 52 can be extended while under compression or tensile stress when the anchor 105 is activated. To extend the liner 52 under compression, the anchor 70 can be activated and engaged, as shown in [reference]. Fig. Figure 6 shows that to expand the liner 52 under tensile stress, the anchor 70 can be deactivated to release the upper end 53. It is understood that in both situations, tensile stress and compression can be present on the liner 52 (e.g., during compression, the section of the liner 52 downstream of the anchor 70 may be under tensile stress). Thus, the aforementioned tensile stress or compression is a predominant condition, as opposed to the only condition.

[0023] Overall, it should be noted positively that during the expansion of the liner 52, the pressure in the pressure chamber 100 is not transmitted to the inner bore of the liner 52. Rather, the dynamic seals 84 maintain a sealing barrier over the bore 82 while the connector(s) 94 shift or move axially upwards. The pressure isolation of the bore 82 is maintained throughout the entire expansion process.

[0024] Now, referring to Fig. Figure 7 shows the first cone 62 and the second cone 64 of the expansion device 60, which move axially through the liner 52 and gradually expand the liner 52 to a first diameter and then to a second, larger diameter. Now, referring to Fig. Figure 8 shows a liner shoe 106 of the liner 52, which is expanded by the expansion device 60 and sealed with a borehole wall 108.

[0025] Now, referring to Fig. Figure 9 shows a step that can be taken to reduce the tensile stress in the liner 52. Overall, expanding the diameter of the liner 52 causes a reduction in the length of the liner 52. During the step of Fig. The liner 52 is attached at both ends (Figure 8). Therefore, the partially extended liner 52 is under tension. To reduce this tension, the anchor 70 can be released and then reinstalled, as shown.

[0026] In one variant, the liner 52 can be designed to be installed with a prestress value selected based on a predicted expansion caused by in-situ applied thermal energy. For example, the liner 52 may be expected to elongate in geothermal boreholes due to thermal expansion. For such situations, the liner 52 can be continuously expanded and anchored in place. A liner suitable for such situations may have either an open-bore packer on the expandable liner shoe or another anchoring device that secures the liner shoe in the open borehole. Therefore, the liner can be expanded in a state where both ends are fixed, preventing axial shortening. In this arrangement, the prestress induced by the expansion remains after the liner and the master liner have been fixed in the borehole.When the liner heats up to borehole temperatures, the preload is reduced to approximately neutral due to thermal expansion.

[0027] In conventional geothermal applications, the casing is fully cemented to the surface to provide complete support and reduce the risk of buckling due to compressive stress during heating. The method described above, which secures both ends, can eliminate the need for a full cement casing and potentially the need for cement altogether.

[0028] Now, referring to Fig. Figure 10 shows the expansion device 60, which enters a region 112 where the liners 52 and 54 overlap. When the expansion device 60 reaches a shoe 114 of the master liner 54, the axial movement of the expansion device 60 is prevented. Since the pressure chamber 100 can no longer expand when fluid is pumped into it, the pressure reaches a maximum. As shown in Fig. As shown in Figure 11, as soon as the pressure in the pressure chamber 100 rises to a predetermined value, a decoupling device (not shown) is activated, allowing the anchor 70 to separate from the liner 52. Suitable pressure-activated decoupling devices can be used to separate the anchor 70 from the liner 52.

[0029] Now, referring to Fig. 12, a combination of increased pressure by pumping fluid and “overpull” (pulling up the working strand 18) is applied to the liner assembly 50. These tensile stress forces activate a retraction device 116 in the expansion device 60, which allows the lower cone 64 to retract. For example, a shear bolt (not shown) can be calibrated or designed to break and allow the lower cone 64 to collapse when it encounters a predetermined force (e.g., tensile stress force).

[0030] Now, referring to Fig. 13, the upper cone 62 of the expansion device 60 continues the expansion of the liner 52. It should be noted that the upper end of the liner 52 separates axially from the anchor 70 due to the shortening that occurs during expansion. Fig. Figure 14 shows the fully extended liner 52.

[0031] Now, referring to Fig.Figure 15 shows the expansion device 60, which engages the anchor 70 and the lower sealing element 80. This engagement activates a bypass (not shown) in the lower sealing element 80, allowing fluid communication via the lower sealing element 80. Consequently, when the liner system 50 is withdrawn from the borehole 12, the fluid can flow up the borehole from the lower sealing element 80 and down the borehole from the lower sealing element 80.

[0032] The term "work train" as used here refers to any device, device component, combination of devices, means, and / or element that can be used to transport, receive, support, or otherwise facilitate the use of another device, device component, combination of devices, means, and / or element. Exemplary, non-limiting work trains include wound-tube drill strings, drill strings constructed from joined tubes, and any combination or section thereof. Other examples of supports include casing tubes and wellbore sub-assemblies.

[0033] The foregoing description is directed, for the purpose of illustration and explanation, to certain embodiments of the present disclosure. However, it is obvious to the person skilled in the art that many variations and modifications of the embodiment described above are possible without departing from the scope of the disclosure.

Claims

[1] Method for lining a borehole (12) comprising: Placing a first liner (54) in the borehole (12), wherein the first liner (54) has a lower section, Placing a second liner (52) in the borehole (12), wherein an upper section of the second liner (52) is placed in the lower section of the first liner (54), Positioning an upper sealing element (90) and a lower sealing element (80) in the borehole (12) to form a pressure chamber (100), wherein the upper sealing element (90) and the lower sealing element (80) move axially away from each other, the axial movement causing the working string (18) to move upwards and pull an expansion device (60) through a bore (82) of the second liner (52), Expanding the second liner (52) using the pressure chamber (100) and Positioning the upper sealing element (90) and the lower sealing element (80) in the first liner (54) and over the second liner (52), thereby hydraulically isolating an inner bore (82) of the second liner (52) from the pressure chamber (100). [2] Method according to claim 1, further comprising anchoring the second liner (52) to the first liner (54) using an anchor (70). [3] Method according to claim 2, further comprising activating the anchor (70) using the pressure chamber (100). [4] Method according to claim 1, wherein the expansion is carried out using the expansion device (60) which is connected to a working strand (18) via at least one connector (94). [5] Method according to claim 4, further comprising attaching the upper sealing element (90) to the working string (18). [6] Method according to claim 4, further comprising the formation of a fluid seal (92) using at least one dynamic seal (92) for hydraulically isolating the inner bore (82) of the second liner (52). [7] Method according to claim 4, further comprising conveying the upper and lower sealing element (90, 80) into the borehole (12) using the working string (18). [8] Method according to claim 4, further comprising pumping a fluid down through the working string (18) to pressurize the pressure chamber (100). [9] The method of claim 1 further comprising: Securing the ends of the second liner (52) during expansion to achieve a selected prestress and Securing the second liner (52) with the selected prestress in the borehole (12). [10] Method for lining a borehole (12) comprising: Placing a first liner (54) in the borehole (12), wherein the first liner (54) has a lower section, Placing a second liner (52) in the borehole (12), wherein an upper section of the second liner (52) is placed in the lower section of the first liner (54), Positioning an upper sealing element (90) and a lower sealing element (80) in the borehole (12) to form a pressure chamber (100), Pumping a fluid down through the working train (18) to pressurize the pressure chamber (100), and Expansion of the second liner (52) using the pressure chamber (100), wherein the upper sealing element (90) and the lower sealing element (80) move axially away from each other, wherein the axial movement causes the working string (18) to move upwards and to pull an expansion device (60) through a bore (82) of the second liner (52), and wherein the expansion is carried out using the expansion device (60) which is connected to the working string (18) via at least one connector (94). [11] Device for positioning a first liner (54) and a second liner (52) in a borehole (12), wherein the second liner (52) has an upper section which is placed in a lower section of the first liner (54), wherein the device at least one upper sealing element (90), at least one lower sealing element (80) which cooperates with the at least one upper sealing element (90) to form a pressure chamber (100) which is hydraulically isolated from an inner bore (82) of the second liner (52), wherein the at least one upper sealing element (90) and the at least one lower sealing element (80) are positioned in the first liner (54) and above the second liner (52), and wherein the at least one upper sealing element (90) and the at least one lower sealing element (80) are configured such that they separate axially in response to a pressure in the pressure chamber (100), a working string (18) configured to convey the at least one upper sealing element (90) and the at least one lower sealing element (80) into the borehole (12), wherein the axial movement causes the working string (18) to move upwards and to draw an expansion device (60) through a bore (82) of the second liner (52), at least one connector (94) connected to the working strand (18) and extending through the pressure chamber (100) and the second liner (52), and the expansion device (60) connected to the connector (94), wherein the expansion device (60) is designed to expand the second liner (52) in a manner that causes axial separation of the at least one upper sealing element (90) and the at least one lower sealing element (80). [12] Device according to claim 11, further comprising an anchor (70) configured to selectively anchor the second liner (52) to the first liner (54), wherein the anchor (70) is activated using the pressure chamber (100). [13] Device according to claim 12, wherein the anchor (70) has a decoupling device configured to decouple the anchor (70) from the second liner (52), the decoupling device being activated by using the pressure chamber (100). [14] Device according to claim 11, in which at least a part of the pressure chamber (100) is formed in a bore of the first liner (54). [15] Device according to claim 11, in which the working train (18) is designed such that it allows fluid to flow into the pressure chamber (100). [16] Device according to claim 11, in which the at least one upper sealing element (90) is attached to the working string (18). [17] Device according to claim 11, further comprising a dynamic seal (92) surrounding the at least one connector (94) and designed to allow axial movement of the at least one connector (94) while maintaining a seal.

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