Downhole system

Abstract

The present invention relates to a downhole system for plugging and disposing a well having a wellhead, the downhole system comprising: a first well tubular metal structure arranged in a wellbore; a barrier disposed inside or around the first well tubular metal structure, separating the first cavity from the second cavity, the barrier having a top surface facing the first cavity and a bottom surface facing the second cavity, where the barrier has a temperature activated bypass assembly comprising a bypass channel and a blocking member, the bypass channel extends from the top surface to the bottom surface for providing fluid communication between the first cavity and the second cavity when the obstructing member is removed by heating. The invention also relates to a downhole method for plugging and disposing a downhole system.

Description

Technical Field

[0001] This invention relates to a downhole system for sealing and abandoning wells with a top. The invention also relates to a downhole method for sealing and abandoning a downhole system. Background Technology

[0002] When a well's production declines and all attempts to increase reservoir hydrocarbon production fail, the portion of the well that has lost production (if not the entire well) is plugged and abandoned. Pluging and abandonment are critical stages in a well's lifecycle. This is a costly process because authorities have stringent requirements for plugging operations to ensure that the well does not pollute the environment.

[0003] When planning a well, the cost of sealing and abandonment must be guaranteed to avoid the relevant departments bearing huge costs for well sealing and abandonment. Therefore, well operators always seek lower-cost sealing and abandonment solutions in order to reduce the deposit.

[0004] In some cased wells, there are sections where the casing or production tubing is surrounded by an annulus, which is not cemented during completion. This type of cased well may also have an annulus in the upper part of the well, between the intermediate casing and the production casing. In wells with annulus or annulus, plugging and disposal become complicated because when the well is plugged with cement-filled casing, the cement may not completely fill the annulus or annulus, posing a risk of a blowout from that annulus or annulus. To properly plug the well, a large drilling rig is brought to the well to pull the production casing out of the well. Therefore, this operation is necessary and expensive in known solutions.

[0005] To access the annulus, the pipe can be removed using fireworks or explosives, but this poses a risk to the remainder of the well completion because other barriers may be damaged, making the risk of plugging and disposal of leaks too high. Summary of the Invention

[0006] The purpose of this invention is to overcome, in whole or in part, the aforementioned disadvantages and deficiencies of the prior art. More specifically, the purpose is to provide an improved downhole system capable of sealing a casing well having an annulus between the casing / production tubing and the formation, and / or between the intermediate casing and the production casing, without posing a risk to the remainder of the well completion.

[0007] The foregoing objectives, along with numerous other objectives, advantages, and features (which will become apparent in the following description), are achieved by a solution according to the invention, namely a downhole system or downhole completion system for sealing and abandoning wells with wellheads, comprising: -The first tubular metal structure arranged in the wellbore, and A barrier, disposed inside or around the first well tubular metal structure, isolates the first cavity from the second cavity. The barrier has a top surface facing the first cavity and a bottom surface facing the second cavity. The barrier has a temperature-activated bypass assembly that includes a bypass channel and a blocking component. The bypass channel extends from the top surface to the bottom surface to provide fluid communication between the first cavity and the second cavity when the blocking component is removed by heating.

[0008] The blocking components can be arranged to obstruct fluid flow through the bypass channel.

[0009] By incorporating a temperature-activated bypass component, this barrier functions as a conventional barrier during well production. When it is necessary to block part (if not all) of the well, the blocking component is heated above a predetermined temperature, thereby opening the bypass channel and creating fluid communication between the top and bottom surfaces of the barrier. This allows molten metal from the molten portion of the first well tubular metal structure to flow downwards through the bypass channel. In this way, heat buildup above the barrier is avoided, and the risk of such heat unintentionally damaging other parts of the well completion is eliminated.

[0010] Therefore, the barrier is pressure-sealed during deployment and normal operation, but when the applied heat exceeds the melting point of the blocking component, the barrier melts, thus creating a bypass between the top and bottom of the component.

[0011] A downhole system or downhole completion system is a downhole plugging and disposal system.

[0012] Once heated to a predetermined temperature or above, the blocking component can be removed.

[0013] In addition, the predetermined temperature can be below 800°C, preferably below at least 600°C, and more preferably below 400°C.

[0014] In addition, the predetermined temperature can be below 600°C, preferably below 400°C.

[0015] Furthermore, the blocking component can melt at temperatures below 600°C, preferably below 400°C.

[0016] In addition, temperature-activated bypass components may include multiple bypass channels.

[0017] In addition, each bypass channel may include a blocking component.

[0018] Furthermore, the blocking component can be melted at at least 600°C, preferably at at least 1000°C.

[0019] In addition, the blocking component can be arranged inside the bypass channel or on top of the bypass channel.

[0020] In addition, the blocking component can be a meltable, moldable, or fusible blocking component.

[0021] In addition, the blocking component can be an internal blocking component or part of a bypass channel.

[0022] In addition, the barrier can be a plug arranged within the first well tubular metal structure, such that the first cavity and the second cavity are arranged within the first well tubular metal structure.

[0023] In addition, the barrier can be an annular barrier, which is arranged around the first well tubular metal structure and located between the first well tubular metal structure and the second well tubular metal structure or wellbore, so that the first cavity and the second cavity are annular cavities.

[0024] In addition, ring barriers can also be used to produce packers.

[0025] In addition, the barrier may be a first barrier, and the downhole system may also include a second barrier, the first barrier being arranged around the first well tubular metal structure, and the second barrier being arranged inside the first well tubular metal structure.

[0026] In addition, the second barrier can be a plug, which is arranged inside the first well tubular metal structure to isolate the third cavity above the plug from the fourth cavity inside the first well tubular metal structure.

[0027] In addition, the second barrier may include a temperature-activated bypass component, which includes a bypass channel and a blocking component, the bypass channel extending from the top surface to the bottom surface to provide fluid communication in the bypass channel when the blocking component is removed by heating.

[0028] In addition, the barrier may contain bismuth or bentonite materials.

[0029] In addition, the downhole system may also include an aluminothermic composition disposed inside the first well tubular metal structure above the barrier.

[0030] In addition, the downhole system may include an igniter for igniting the thermite composition.

[0031] In addition, the downhole system may also contain cement, which is placed on top of the first barrier and / or the second barrier after the thermite composition is ignited and a portion of the first well tubular metal structure is melted.

[0032] Furthermore, the annular barrier may include a tubular metal component for installation as part of a first well tubular metal structure, the tubular metal component having an outer surface including: - An expandable metal sleeve surrounding a tubular metal component, having an outer surface facing the inner surface of the tubular metal structure of the wellbore or second well and an inner surface facing the outer surface of the tubular metal component, and each end of the expandable metal sleeve being connected to the tubular metal component. -The annular space between the expandable metal sleeve and the tubular metal component, and - An expansion opening in a tubular metal component allows fluid to enter the annular space, thereby causing the expandable metal sleeve to expand.

[0033] In addition, one end of the expandable metal sleeve can be connected to the tubular metal component via a connecting member, and a bypass channel can extend through the connecting member to provide fluid communication over the entire annular barrier.

[0034] In addition, the tubular metal component may have an axial extension along the axial extension of the first well tubular metal structure.

[0035] In addition, the interior of the tubular metal component can be pressurized to expand the expandable metal sleeve.

[0036] In addition, the bypass channel can extend between the expandable metal sleeve and the tubular metal component to provide fluid communication around the annular barrier when the blocking component is removed by heating.

[0037] The present invention also relates to a downhole method for plugging and disposing of a downhole system according to any of the preceding claims, comprising: - A barrier is provided inside or around the first well tubular metal structure, the barrier having a temperature-activated bypass assembly including a bypass channel and a blocking component, the bypass channel extending from the top surface to the bottom surface to provide fluid communication between the first and second chambers when the blocking component is removed by heating. - Introduce the thermite composition into the tubular metal structure of the first well. - The thermite composition is ignited by an igniter, generating heat that causes an exothermic reduction-oxidation (oxidation-reduction) reaction in the thermite composition.

[0038] -Remove blockage components using heat - Part of the molten first well tubular metal structure - Allow molten metal from the first well tubular metal structure to flow into the second chamber through a bypass channel, and - Introduce cement on top of the barrier. Attached Figure Description

[0039] The invention and its many advantages will now be described in more detail with reference to the accompanying drawings, which are for illustrative purposes only and show some non-limiting embodiments, in which: Figure 1 A shows a partial cross-sectional view of a downhole plugging and disposal system with a temperature-activated bypass component. Figure 1 b showed Figure 1 A partial cross-sectional view of a downhole plugging and disposal system containing an aluminothermic composition.

[0040] Figure 1 c shows Figure 1 b is a partial cross-sectional view of the downhole plugging and disposal system, in which the thermite composition melts a portion of the first well tubular metal structure. Figure 2 A shows a partial cross-sectional view of another downhole plugging and disposal system with a temperature-activated bypass component. Figure 2 b showed Figure 2 A partial cross-sectional view of a downhole plugging and disposal system containing an aluminothermic composition. Figure 2 c shows Figure 2 b is a partial cross-sectional view of the downhole plugging and disposal system, in which the thermite composition melts a portion of the first well tubular metal structure. Figure 3 A partial cross-sectional view of another downhole plugging and disposal system is shown. Figure 4 A partial cross-sectional view of a plug-like barrier with a temperature-activated bypass component is shown. Figure 5 This shows a partial cross-sectional view of a ring-shaped barrier.

[0041] All accompanying drawings are highly schematic and not necessarily drawn to scale. They show only those parts necessary to illustrate the invention, while other parts are omitted or are merely suggested. Detailed Implementation

[0042] Figure 1A shows a downhole system or downhole completion system 100 for sealing and abandoning a well 2 having a wellhead 50. Therefore, this downhole system is a downhole sealing and abandonment system. The downhole system 100 includes a first tubular metal structure 1 disposed in a wellbore 3, and a barrier 4 disposed inside the first tubular metal structure 1, separating a first cavity 101 from a second cavity 102. The top surface 5 of the barrier 4 faces the first cavity 101, and its bottom surface 6 faces the second cavity 102. The barrier 4 has a temperature-activated bypass assembly 7, which includes a bypass channel 8 and a blocking component 9. The bypass channel 8 extends into the barrier 4, but is shown for illustrative purposes only. The bypass channel 8 extends from the top surface 5 to the bottom surface 6 to provide fluid communication between the first cavity 101 and the second cavity 102 when the blocking component 9 is removed by heating. Figure 1 a to Figure 1 In section d, barrier 4 is a plug 4a disposed inside the first well tubular metal structure 1, such that the first cavity 101 and the second cavity 102 are disposed inside the first well tubular metal structure 1. The first well tubular metal structure 1 is at least partially disposed inside the second well tubular metal structure 1b, and a conventional production packer is disposed between the first well tubular metal structure 1 and the second well tubular metal structure 1b, thereby forming an annular space between them. The second well tubular metal structure 1b is disposed in the wellbore 3, and cement 27 is disposed therebetween.

[0043] Therefore, when the temperature is raised by heating, the blocking component 9 of the temperature-activated bypass assembly 7 is melted and flows downward along the bypass channel 8, thereby forming fluid communication from the top surface 5 to the bottom surface 6 inside the bypass channel 8. The blocking component 9 can also evaporate. The blocking component 9 is meltable at temperatures below 600°C, preferably below 400°C.

[0044] When well 2 needs to be sealed and abandoned, the thermite composition 11 is placed inside the tubular metal structure 1 of the first well, above the barrier 4, as follows: Figure 1 As shown in b, the igniter 12 is activated to ignite the thermite composition 11. When the thermite composition 11 undergoes an exothermic reduction-oxidation (redox) reaction, heat is generated, melting portion 30 of the first well tubular metal structure 1, such as... Figure 1 As shown in Figure c, the molten metal 26 from the first well tubular metal structure 1 flows into the second cavity 102 through the bypass channel 8, melting the blocking component 9 to achieve fluid communication. Instead of accumulating on top of the barrier 4, the molten metal 26 flows through the bypass channel 8. As the molten metal 26 flows through the bypass channel 8, heat is also dissipated from the area above the barrier 4, eliminating the risk that the heat generated by the exothermic reaction could damage the second well tubular metal structure 1b or even the surrounding cement 27. After a period of time, cement 27 can be introduced into the area above the barrier 4, where part 30 has been removed, such as... Figure 1 As shown in d, well 2 has been fully sealed. The removal portion 30 of the first well tubular metal structure 1 can exceed 100 meters, preferably exceeds 200 meters, and as... Figure 1 As shown in d, the lengths of the cement plugs 27 set on top of the barrier 4 can be equal.

[0045] The blocking component 9 is an internal blocking component disposed in the top region of the bypass channel 8, but it can also be disposed at the top of the bypass channel 8. The blocking component 9 is a meltable, moldable, or fusible blocking component. The blocking component 9 can also be part of the bypass channel 8, such that the bypass channel 8 and the blocking component 9 are made into a single unit.

[0046] The bypass channel 8 can be a tube made of a high-temperature resistant material (such as ceramic) or a similar material that can withstand temperatures above 1300°C.

[0047] The bypass channel 8 can be a tube made of the same material as the blocking component 9 and melted together with the blocking component 9.

[0048] Figure 2 a shows another downhole system 100, in which a barrier 4 is arranged around the first well tubular metal structure 1, separating the first cavity 101 from the second cavity 102, and in which a bypass channel 8 extends from the top surface 5 to the bottom surface 6 (e.g.) Figure 2 (as shown in b) so as to provide fluid communication between the first cavity 101 and the second cavity 102 when the blocking component 9 is removed by heating.

[0049] The bypass channel 8 extends into the barrier 4, but is shown for illustrative purposes only. Therefore, the barrier 4 is an annular barrier 4b arranged around the first well tubular metal structure 1, located between the first well tubular metal structure 1 and the second well tubular metal structure 1b or the wellbore 3, such that the first cavity 101 and the second cavity 102 are annular cavities. Thus, the annular barrier 4b can serve as a production packer until the bypass channel 8 is used. The barrier 4 is the first barrier 4, and the downhole system 100 also includes a second barrier 10, wherein the first barrier 4 is arranged around the first well tubular metal structure 1, and the second barrier 10 is arranged inside the first well tubular metal structure 1. Therefore, the second barrier 10 is a plug 10a arranged inside the first well tubular metal structure 1, separating the third cavity 103 above the plug 10a from the fourth cavity 104 below the plug 10a within the first well tubular metal structure 1. The second barrier 10 also includes a temperature-activated bypass assembly 7b, which includes a bypass channel 8b and a blocking member 9b, wherein the bypass channel 8b extends from the top surface 5 of the second barrier 10 to the bottom surface 6 of the second barrier 10 to provide fluid communication in the bypass channel 8b of the second barrier 10 when the blocking member 9b is removed by heating (e.g., during an exothermic reaction or in a previous heating operation). The temperature-activated bypass assembly 7b of the barrier includes a plurality of bypass channels 8b, each bypass channel 8b including a blocking member.

[0050] exist Figure 2 In step b, the thermite composition 11 is disposed above the second barrier 10 inside the first well tubular metal structure 1, and then the blocking component 9b is removed by heating (e.g., during an exothermic reaction or in a previous heating operation). Figure 2 In c, a portion 30 of the first well tubular metal structure 1 is melted and flows through the bypass channel 8 in the first barrier 4 and the bypass channel 8b in the second barrier 10.

[0051] exist Figure 2 In d, the downhole system 100 also includes cement 27, which is placed on top of the first barrier 4 and the second barrier 10 after the thermite composition is ignited and a portion of the first well tubular metal structure 1 is melted.

[0052] Barriers 4 and 10 may contain bismuth material or alloy. Therefore, when heated, as long as molten metal 26 passes through bypass channels 8 and 8b, the cavity of barriers 4 and 10 will decrease. After a period of time, barriers 4 and 10 will cool down, and the volume of the bismuth material or alloy will expand, thereby closing bypass channels 8 and 8b, increasing barriers 4 and 10 and further achieving P&A (blocking and disposal).

[0053] like Figure 3As shown, the downhole system includes a barrier 4 having a temperature-activated bypass assembly 7 comprising a bypass channel 8 and a blocking component 9, wherein the bypass channel 8 extends from a top surface 5 to a bottom surface 6 to provide fluid communication between a first cavity 101 and a second cavity 102 when the blocking component 9 is removed by heating. The downhole system 100 also includes a plug 10a, a conventional plug disposed within a first well tubular metal structure 1, which isolates a third cavity 103 above the plug 10a from a fourth cavity 104 below the plug 10a. Once the thermite composition 11 is ignited, a portion 30 of the first well tubular metal structure 1 melts, and molten metal 26 flows radially outward along the bypass channel 8 toward the barriers 4, 10, i.e., the annular barrier 4b, and exits the first cavity into the second cavity 102.

[0054] Figure 4 The diagram shows a blockage-like barrier, with a portion of the blockage shown in a cross-sectional view to reveal the bypass channel 8 and the blocking component 9.

[0055] exist Figure 5 In this design, the annular barrier 4b includes a tubular metal component 16 for mounting as part of a first well tubular metal structure 1 having a longitudinal extension 24. The tubular metal component 16 has an outer surface 17. The annular barrier 4b also includes an expandable metal sleeve 18 surrounding the tubular metal component 16, having an outer surface 19 facing the inner surface of the wellbore or second well tubular metal structure and an inner surface 20 facing the outer surface of the tubular metal component 16. Each end 31, 32 of the expandable metal sleeve 18 is connected to the tubular metal component 16, forming an annular space 21 between the expandable metal sleeve 18 and the tubular metal component 16. The tubular metal component 16 has an expansion opening 22 through which fluid can enter the annular space 21, thereby causing the expandable metal sleeve 18 to expand. At least one end 31, 32 of the expandable metal sleeve 18 is connected to the tubular metal component 16 via connecting members 41, 42. A bypass channel 8 passes through the connecting members 41, 42 and the annular space 21 between the expandable metal sleeve 18 and the tubular metal component 16, thereby providing fluid communication over the entire annular barrier 4b when the blocking member 9 is removed by heating. The tubular metal component 16 has an axial extension 23 along the axial extension 24 of the first well tubular metal structure 1. The tubular metal component 16 has an interior 25 that is pressurized to expand the expandable metal sleeve 18.

[0056] "Fluid" or "well fluid" refers to any fluid that may exist downhole in an oil or gas well, such as natural gas, petroleum, sludge, crude oil, water, etc. "Gas" refers to any type of gaseous component present in a well, well completion, or open hole, and "petroleum" refers to any type of petroleum component, such as crude oil, oil-bearing fluids, etc. Therefore, gas, petroleum, and water fluids may each contain elements or substances other than gas, petroleum, and / or water.

[0057] "Casing" or "well tubular metal structure" refers to any type of pipe, tube, tubular structure, liner, string, etc. used in wells in connection with oil or gas production.

[0058] Although the present invention has been described above in conjunction with preferred embodiments thereof, those skilled in the art will understand that various modifications may be contemplated without departing from the invention as defined in the following claims.

Claims

1. A downhole system (100) for sealing and disposing of a well (2) having a wellhead (50), the downhole system comprising: - A first tubular metal structure (1), which is arranged in the wellbore (3), and - A barrier (4), disposed inside or around the first well tubular metal structure, isolates the first cavity (101) from the second cavity (102), the barrier having a top surface (5) facing the first cavity and a bottom surface (6) facing the second cavity, wherein the barrier has a temperature-activated bypass assembly (7), the bypass assembly including a bypass channel (8) and a blocking component (9), the blocking component being arranged to block fluid communication through the bypass channel, the bypass channel extending from the top surface to the bottom surface, so as to provide fluid communication between the first cavity and the second cavity when the blocking component is removed by heating.

2. The downhole system according to claim 1, wherein, The blocking component is disposed within the bypass channel or on top of the bypass channel.

3. The downhole system according to claim 1 or 2, wherein, The blocking component is a meltable, moldable, or fusible blocking component.

4. The downhole system according to any one of the preceding claims, wherein, The blocking component is either an internal blocking component or part of the bypass channel.

5. The downhole system according to any one of the preceding claims, wherein, The barrier is a plug (4a) arranged within the first well tubular metal structure, such that the first cavity and the second cavity are arranged within the first well tubular metal structure.

6. The downhole system according to any one of claims 1-4, wherein, The barrier is an annular barrier (4b), which is arranged around the first well tubular metal structure between the first well tubular metal structure and the second well tubular metal structure (1b) or the wellbore, such that the first cavity and the second cavity are annular cavities.

7. The downhole system according to claim 6, wherein, The ring barrier is a production packer.

8. The downhole system according to any one of claims 1-4, wherein, The barrier is a first barrier (4), and the downhole system also includes a second barrier (10). The first barrier is arranged around the first well tubular metal structure, and the second barrier is arranged within the first well tubular metal structure.

9. The downhole system according to claim 8, wherein, The second barrier (10) is a plug (10a) arranged within the first well tubular metal structure, thereby separating the third cavity (103) above the plug from the fourth cavity (104) below the plug within the first well tubular metal structure.

10. The downhole system according to claim 8 or 9, wherein, The second barrier includes a temperature-activated bypass component (7b) comprising a bypass channel (8b) and a blocking component (9b) extending from the top surface to the bottom surface to provide fluid communication in the bypass channel when the blocking component is removed by heating.

11. The downhole system according to any one of the preceding claims, wherein, The barrier contains bismuth material.

12. The downhole system according to any of the preceding claims, further comprising an aluminothermic composition (11) disposed within the first tubular metal structure above the barrier.

13. The downhole completion system according to claim 12, further comprising an igniter (12) for igniting the thermite composition.

14. The downhole system of claim 12 or 13, further comprising cement, which is disposed on top of the first barrier and / or the second barrier after the thermite composition is ignited and a portion of the first tubular metal structure is melted.

15. The downhole system according to claim 6 or 7, wherein, The annular barrier includes a tubular metal component (16) for installation as part of the first well tubular metal structure, the tubular metal component having an outer surface (17) comprising: - An expandable metal sleeve (18) surrounds the tubular metal component and has an outer surface (19) facing the inner surface of the wellbore or the second well tubular metal structure and an inner surface (20) facing the outer surface of the tubular metal component, and each end (31, 32) of the expandable metal sleeve is connected to the tubular metal component. -The annular space (21) between the expandable metal sleeve and the tubular metal component, and - The expansion opening (22) in the tubular metal component allows fluid to enter the annular space through the expansion opening, thereby causing the expandable metal sleeve to expand.

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