An inflatable metal tubular external packer

Abstract

The application provides an inflatable metal tubular external packer, which comprises a central pipe, a liquid inlet hole is arranged on the central pipe, a setting assembly is arranged outside the central pipe, the setting assembly is configured to be capable of unfolding outwardly and setting under the action of internal pressure, wherein, in an initial state, the setting assembly is in a closed state with the liquid inlet hole, when the pressure in the central pipe increases to a certain degree, the liquid inlet hole communicates with the setting assembly, and the setting assembly is guided by the pressure to complete setting, and after the setting is completed, the setting assembly is closed with the liquid inlet hole. The metal setting assembly, such as an inflatable metal outer cylinder and an inflatable metal ring, is used as a tubular external packer sealing element, can bear high temperature, ensures the annular sealing effect under high temperature conditions, and ensures the wellbore integrity.

Description

Technical Field

[0001] This invention relates to an expandable metal tube packer, belonging to the field of oil and gas extraction technology. Background Technology

[0002] The eastern oilfield has large reserves of heavy oil in numerous blocks, and steam injection and steam drive are the main development methods for heavy oil thermal recovery. Due to the high downhole temperature (≥300℃), high-temperature resistant external packers must be used to complete the annulus isolation, thereby improving the development life of wells constructed using the open-hole completion process in horizontal wells.

[0003] The most commonly used segmentation tool is the external packer, whose sealing cylinder is made of rubber. However, rubber has limited temperature resistance (maximum temperature resistance 200℃), which cannot meet the long-term sealing requirements of thermal recovery wells under high-temperature steam injection conditions. When the temperature reaches above 300℃, the rubber material loses its original elasticity and "flows," rendering the rubber seal incapable of performing the high-pressure sealing task. Consequently, the external packer fails, unable to effectively seal the annular space gaps, thus compromising the integrity of the wellbore. High-temperature aging of the rubber often leads to pressure cross-contamination between different production layers and a rapid increase in water cut after water emerges from the water layer, severely hindering the effective development of heavy oil reservoirs. Summary of the Invention

[0004] To address the aforementioned technical problems in existing technologies, this invention proposes an expandable metal external packer. It employs metal setting components, such as an expandable metal outer cylinder and an expandable metal ring, as the sealing elements of the external packer, capable of withstanding high temperatures (greater than 300°C). This ensures effective annular sealing under high-temperature conditions and guarantees wellbore integrity.

[0005] This invention proposes an expandable metal tube external packer, comprising:

[0006] A central tube, wherein a liquid inlet hole is provided on the central tube;

[0007] A setting assembly disposed outside the central tube, the setting assembly being configured to unfold outward and set under internal pressure;

[0008] In the initial state, the setting assembly and the liquid inlet are closed; when the pressure in the central tube increases to a certain level, the liquid inlet connects with the setting assembly and introduces pressure into the setting assembly to complete the setting; after the setting is completed, the setting assembly and the liquid inlet are closed.

[0009] A further improvement of the present invention is that the setting assembly includes an outer protective sleeve disposed on the upper part of the outside of the central tube, and a lower plug disposed on the lower part of the outside of the central tube; an expandable metal outer cylinder is disposed between the outer protective sleeve and the central tube, and the expandable metal outer cylinder expands under the action of internal pressure to complete the setting.

[0010] A further improvement of the present invention is that a cavity is formed between the expandable metal outer cylinder and the central tube, and the expansionable metal outer cylinder is pushed to expand when the pressure inside the cavity increases.

[0011] A further improvement of the present invention is that an annular space is provided between the outer protective sleeve and the central tube, and the annular space is connected to the cavity; an activation and deactivation mechanism is provided in the annular space; the activation and deactivation mechanism controls the liquid inlet to be connected to or disconnected from the cavity.

[0012] A further improvement of the present invention is that the starting and stopping mechanism includes a starting sleeve and a stopping sleeve, wherein when the starting sleeve is started, the liquid inlet is connected to the cavity; and when the stopping sleeve is started, the liquid inlet is disconnected from the cavity.

[0013] A further improvement of the present invention is that the starting sleeve is disposed below the closing sleeve, close to the cavity; and the starting sleeve is connected to the outer protective sleeve by a starting pin.

[0014] A further improvement of the present invention is that the closing sleeve is provided with a liquid guiding hole, which is connected to the liquid inlet hole in the initial state, and the closing sleeve and the outer protective sleeve are connected by a closing pin; after the closing pin is broken, the liquid guiding hole and the liquid inlet hole are misaligned, thereby disconnecting the liquid inlet hole from the cavity.

[0015] A further improvement of the present invention is that, when the closing sleeve is in its initial position, there is a certain distance between it and the upper end of the annular space, forming a moving space; after the closing pin is disconnected, the closing sleeve moves into the moving space and disconnects the liquid inlet from the cavity.

[0016] The outer protective sleeve has a through hole at the position corresponding to the movable space.

[0017] A further improvement of the present invention is that a filter screen is provided on the through hole.

[0018] A further improvement of the present invention is that a plurality of annular grooves are provided on the outer wall of the expandable metal outer cylinder, an expandable metal ring is provided in the annular grooves, and a plurality of serrated structures are provided on the outer wall of the expandable metal ring.

[0019] Before the expandable outer cylinder expands, the outer diameter of the expandable metal ring is smaller than the outer diameter of the plug; after the expandable outer cylinder expands, the outer diameter of the expandable metal ring is larger than the outer diameter of the plug.

[0020] A further improvement of the present invention is that a limiting step is provided in the middle of the central tube. After the starting pin breaks, the starting sleeve moves into the cavity under the action of liquid pressure and falls on the limiting step.

[0021] A further improvement of the present invention is that an upper connector is provided at the upper end of the central tube and a lower connector is provided at the lower end; the inner side of the upper connector is connected to the central tube by a thread, and the outer side is connected to the outer protective sleeve by a thread, and the thickness of the upper connector corresponds to the width of the annular space.

[0022] Compared with the prior art, the advantages of the present invention are as follows:

[0023] The expandable metal external packer of this invention uses metal setting components, such as an expandable metal outer cylinder and an expandable metal ring, as the sealing elements of the external packer, which can withstand high temperatures (greater than 300°C). This ensures the annular sealing effect under high-temperature conditions and guarantees the integrity of the wellbore.

[0024] In the expandable metal tube packer of the present invention, the metal expansion outer cylinder and the expandable metal ring are the components that come into contact with the well wall after the outer diameter of the packer is increased. The metal has high temperature resistance and high strength, which has obvious advantages compared with conventional rubber materials.

[0025] In this invention, during the assembly process of the expandable metal tube packer, the inner cavity formed by the metal expansion outer cylinder, outer protective sleeve, starting sleeve, and central tube is filled with hydraulic oil. This prevents damage to the metal expansion outer cylinder caused by the packer being subjected to large external fluid pressure during the well insertion process.

[0026] In this invention, after the expandable metal tube packer is set, the closing sleeve can move upward to close the inlet hole, preventing the liquid pressure in the central tube from affecting the expandable metal tube packer during subsequent construction. Attached Figure Description

[0027] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, in which:

[0028] Figure 1 The diagram shown is a structural schematic of an expandable metal tube packer according to an embodiment of the present invention, illustrating its initial state.

[0029] Figure 2 The diagram shown is a structural schematic of an expandable metal tube packer according to an embodiment of the present invention, illustrating the setting state;

[0030] Figure 3 The diagram shown is a structural schematic of an expandable metal tube packer according to an embodiment of the present invention, showing the closed state;

[0031] In the accompanying drawings, the same parts use the same reference numerals. The drawings are not drawn to scale.

[0032] The meanings of the reference numerals in the attached figures are as follows:

[0033] 1. Central tube,

[0034] 2. Outer protective cover

[0035] 3. Metal expandable outer cylinder,

[0036] 4. Lower the plug,

[0037] 11. Connect the connector.

[0038] 12. Lower connector,

[0039] 13. Liquid inlet hole,

[0040] 14. Limiting step,

[0041] 21. Circular space,

[0042] 22. Mobile space

[0043] 23. Starting and stopping mechanism,

[0044] 24. Starter kit

[0045] 25. Close the cover.

[0046] 26. Start the pin.

[0047] 27. Close the pin.

[0048] 28. Liquid guiding hole,

[0049] 29. Through hole,

[0050] 31. Cavity

[0051] 32. Expandable metal ring. Detailed Implementation

[0052] To make the technical solutions and advantages of the present invention clearer, exemplary embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not an exhaustive list of all embodiments. Furthermore, without conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0053] Figure 1 The diagram schematically illustrates an expandable metal tube packer according to the present invention, comprising a central tube 1, which has a tubular structure and an inlet port 13 on its outer wall. A setting assembly is disposed outside the central tube 1, which expands outward and sets under internal pressure. In this embodiment, initially, the setting assembly and the inlet port 13 are closed; when the pressure inside the central tube 1 increases to a certain level, the inlet port 13 communicates with the setting assembly and introduces pressure into the setting assembly to complete the setting; after setting, the setting assembly and the inlet port 13 are closed.

[0054] When using the expandable metal external packer according to this embodiment, the expandable metal external packer is installed in the completion work string. In the initial state (e.g.) Figure 1 As shown), the setting assembly and the inlet port 13 are in a closed state. After being lowered to the designed downhole position, the inlet port 13 connects with the setting assembly (as shown). Figure 2 As shown), the liquid in the central tube 1 enters the setting assembly, expands under the liquid pressure, and completes the setting process. Afterwards, the setting assembly closes the connection with the inlet port 13 (as shown). Figure 3 (As shown).

[0055] In one embodiment, the setting assembly includes an outer protective sleeve 2, a metal expandable outer cylinder 3, and a lower plug 4. The outer protective sleeve 2 is disposed on the upper part of the outside of the central tube 1, the lower plug 4 is disposed on the lower part of the outside of the central tube 1, and the metal expandable outer cylinder 3 is disposed between the outer protective sleeve 2 and the lower plug 4. The metal expandable outer cylinder 3 expands under the action of internal pressure to complete the setting.

[0056] In the expandable metal external packer described in this embodiment, the sealing is achieved by the expansion of the expandable metal outer cylinder 3 under pressure, eliminating the need for rubber sealing components and allowing it to withstand high temperatures (above 300°C). When oil wells are developed using thermal recovery methods, the wellbore temperature can reach over 300°C under the influence of high-temperature steam. At this temperature, the rubber sleeve of conventional external packers deforms or even carbonizes, failing to maintain tight contact between the rubber material and the wellbore, thus causing annular sealing failure. The expandable metal external packer can still function normally at high temperatures, ensuring the annular sealing effect under high-temperature conditions and guaranteeing wellbore integrity.

[0057] In one embodiment, a cavity 31 is formed between the expandable metal outer cylinder 3 and the central tube 1, and the expansion of the expandable metal outer cylinder 3 is pushed to expand when the pressure in the cavity 31 increases.

[0058] During the assembly of the expandable metal tube packer, the cavity 31 between the expandable metal outer cylinder 3 and the central tube 1 can be filled with hydraulic oil. This can prevent the expandable metal tube packer described in this embodiment from being damaged by the large external liquid pressure during the well run-in process.

[0059] In one embodiment, an annular space 21 is provided between the outer protective sleeve 2 and the central tube 1, and the lower end of the annular space 21 is connected to the cavity 31. An opening and closing mechanism 23 is provided in the annular space 21, and the opening and closing mechanism 23 controls the liquid inlet 13 to be connected to or disconnected from the cavity 31.

[0060] After the expandable metal tube packer as described in this embodiment is inserted, the channel between the inlet port 13 and the cavity 31 is opened by the start and stop mechanism 23 (e.g., Figure 1 As shown), the inlet hole 13 is connected to the cavity 31. At this time, the central tube 1 is connected to the cavity 31, and the fluid in the central tube 1 flows into the cavity 31, increasing the pressure inside the cavity 31. The pressure inside the cavity 31 pushes the expandable metal outer cylinder 3 to expand and set (as shown). Figure 2 (As shown). After the setting is completed, the start and stop mechanism 23 controls the disconnection between the liquid inlet 13 and the cavity 31, so that the pressure in the cavity 31 remains stable and the setting state is always maintained (as shown). Figure 3 (As shown).

[0061] In one embodiment, the starting and stopping mechanism 23 includes a starting sleeve 24 and a stopping sleeve 25. Initially, the starting sleeve 24 blocks the space between the liquid inlet 13, the stopping sleeve 25, and the cavity 31. After starting, the starting sleeve 24 moves away and enters the cavity 31, at which point the liquid inlet 13 is connected to the cavity 31 via the stopping sleeve 25. After sealing is completed, the stopping sleeve 25 starts and moves away from its original position, disconnecting the liquid inlet 13 from the cavity 31.

[0062] When using the expandable metal external packer according to this embodiment, the expandable metal external packer is installed in the completion work string. In the initial state (e.g.) Figure 1 As shown), the starting sleeve 24 blocks the gap between the inlet port 13 and the cavity 31. After being lowered to the designed downhole position, the starting sleeve 24 is activated and slides into the cavity 31. The inlet port 13 and the cavity 31 are connected through the closing sleeve 25. The liquid in the central tube 1 enters the expandable metal outer cylinder 3, which expands under the liquid pressure to complete the setting. Then, the closing sleeve 25 is moved, closing the channel between the cavity 31 and the inlet port 13 (as shown). Figure 2 (As shown).

[0063] In one embodiment, the start sleeve 24 is disposed below the stop sleeve 25, near the cavity 31; and the start sleeve 24 is connected to the outer protective sleeve 2 via a start pin 26.

[0064] When the pressure inside the central tube 1 increases to a certain value, the starting pin 26 will break under the pressure. This causes the starting sleeve 24 to lose its connection with the outer protective sleeve 2, and the starting sleeve 24 moves downwards under the pressure of the liquid and enters the cavity 31. Since the width of the cavity 31 is greater than the width of the annular space 21, the starting sleeve 24 will not obstruct the fluid flow within the cavity 31. Without the obstruction of the starting sleeve 24, the fluid in the central tube 1 enters the cavity 31, thereby increasing the pressure within the cavity 31 and causing the expandable metal outer cylinder 3 to expand and set.

[0065] In one embodiment, the closing sleeve 25 is provided with a liquid guiding hole 28. In the initial state, the liquid guiding hole 28 is connected to the liquid inlet hole 13, and the closing sleeve 25 is connected to the outer protective sleeve 2 by a closing pin 27. After the closing pin 27 is disconnected, the liquid guiding hole 28 is offset from the liquid inlet hole 13, thereby disconnecting the liquid inlet hole 13 from the cavity 31.

[0066] In the expandable metal tube packer according to this embodiment, the closing sleeve 25 has a cylindrical structure, and its liquid guiding hole 28 is divided into two sections: one section is arranged radially inward, and the other section is arranged axially. The radially arranged section is opposite to and connected to the liquid inlet hole 13 in the initial state; the axially arranged section is aligned with the opening sleeve in the initial state, and connects to the cavity 31 after the opening sleeve is removed.

[0067] After the sealing is completed, (such as...) Figure 2 (As shown) After the fluid in the central tube 1 enters the cavity 31, the pressure inside the cavity 31 increases, causing an increase in the axial pressure received by the closing sleeve 25. When the axial pressure increases to a certain value, the closing pin 27 breaks. Under the pushing action of the axial pressure, the closing sleeve 25 moves upward, and its radial end liquid guide hole 28 is misaligned with the liquid inlet hole 13, causing the liquid inlet hole 13 to lose communication with the cavity 31 (as shown). Figure 3 (As shown).

[0068] In one embodiment, the closing sleeve 25 is initially positioned at a certain distance from the upper end of the annular space 21, forming a movable space 22 (the movable space 22 is the upper half of the annular space 21). After the closing pin 27 is disengaged, the closing sleeve 25 moves into the movable space 22, disconnecting the liquid inlet 13 from the cavity 31.

[0069] The outer protective sleeve 2 has a through hole 29 at the position corresponding to the moving space 22.

[0070] In the packer according to this embodiment, the moving space 22 can accommodate the movement of the closing sleeve 25, so that the closing sleeve 25 can be stably positioned within the moving space 22 when closed, keeping the liquid guide hole 28 and the liquid inlet hole 13 in a staggered state. The through hole 29 of the outer protective sleeve 2 can connect the moving space 22 and the external annulus, ensuring that the fluid in the moving space 22 can be smoothly discharged during the upward movement of the closing sleeve 25 without causing resistance to the movement of the closing sleeve 25.

[0071] In a preferred embodiment, a filter screen is provided on the through hole 29. The filter screen can ensure the flow of liquid while filtering out mud and sand, ensuring that mud and sand do not enter the moving space 22.

[0072] In one embodiment, the outer wall of the expandable metal outer cylinder 3 is provided with a plurality of annular grooves, an expandable metal ring 32 is provided in the annular grooves, and the outer wall of the expandable metal ring 32 is provided with a plurality of serrated structures.

[0073] Before the expandable outer cylinder 3 expands, the outer diameter of the expandable metal ring 32 is smaller than the outer diameter of the plug. After the expandable outer cylinder 3 expands, the outer diameter of the expandable metal ring 32 is larger than the outer diameter of the plug.

[0074] In the initial state (e.g.) Figure 1 (As shown) Because the outer diameter of the expandable metal ring 32 is smaller than the outer diameter of the plug before the expandable outer cylinder 3 expands, the serrated structure of the outer wall of the expandable metal ring 32 ensures that it will not affect the process of lowering the cylinder into the well. After the expandable outer cylinder 3 expands, the outer diameter of the expandable metal ring 32 is larger than the outer diameter of the plug (e.g., Figure 3 As shown in the figure, the serrated structure on the outer wall of the expandable metal ring 32 is engaged with the sleeve, thereby connecting with the sleeve and completing the setting seal.

[0075] In one embodiment, a limiting step 14 is provided in the middle of the central tube 1. After the starting pin 26 breaks, the starting sleeve 24 moves into the cavity 31 under the action of liquid pressure and falls on the limiting step 14.

[0076] In one embodiment, the upper end of the central tube 1 is provided with an upper connector 11, and the lower end is provided with a lower connector 12. The upper connector 11 and the lower connector 12 are used to connect other upstream and downstream components. The inner side of the upper connector 11 is threaded to the central tube 1, and the outer side is threaded to the outer protective sleeve 2. The thickness of the upper connector 11 corresponds to the width of the annular space 21.

[0077] In using the expandable metal external packer according to this embodiment, the packer is assembled and installed in the well completion work string via the upper connector 11 and the lower connector 12. The packer is then lowered to the downhole installation location (e.g., ...). Figure 1 (As shown) Increase the pressure inside the central tube 1. The pressure is applied to the starting sleeve 24 through the liquid inlet 13 and the liquid guide hole 28. When the pressure increases to a certain value, the starting pin 26 is sheared. At this time, the starting sleeve 24 separates from the outer protective sleeve 2. Under the pushing action of the pressure, the starting sleeve 24 moves downward into the cavity 31 and falls onto the limiting step 14.

[0078] In this way, the liquid guide hole 28 on the closed sleeve 25 can connect the liquid inlet hole 13 and the cavity 31, allowing the fluid in the central tube 1 to enter the cavity 31. Under the action of fluid pressure, the expandable metal outer cylinder 3 begins to expand. When the serrated structure on the outer wall of the expandable metal outer cylinder 3 engages with the sleeve, the expandable metal outer cylinder 3 is connected to the sleeve, completing the setting seal (e.g., Figure 2 (As shown).

[0079] After setting, the volume of cavity 31 no longer changes. The increased internal pressure exerts pressure on the closing sleeve 25. When the pressure reaches a certain value, the closing pin 27 is sheared, and the closing sleeve 25 moves upward under the pressure, thus moving into the moving space 22. Fluid in the moving space 22 flows out through the through hole 29.

[0080] At this point, the liquid guide hole 28 on the closing sleeve 25 is offset from the liquid inlet, preventing the fluid in the central tube 1 from flowing into the cavity 31 through the liquid inlet hole 13, thus closing the seal. This maintains the set seal state (e.g., Figure 3 (As shown).

[0081] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and / or modifications falling within the scope of the invention, and all changes and / or modifications made according to embodiments of the invention should be covered within the protection scope of the invention.

Claims

1. An expandable metal tube external packer, characterized in that, include: A central tube (1) is provided with a liquid inlet hole (13). A setting assembly disposed outside the central tube (1) is configured to unfold outward and set under internal pressure; In the initial state, the setting assembly and the inlet hole (13) are closed; when the pressure in the central tube (1) increases to a certain level, the inlet hole (13) connects with the setting assembly and introduces pressure into the setting assembly to make the setting assembly complete the setting; after the setting is completed, the setting assembly and the inlet hole (13) are closed. The setting assembly includes an outer protective sleeve (2) disposed on the upper part of the outside of the central tube (1) and a lower plug (4) disposed on the lower part of the outside of the central tube (1); a metal expandable outer cylinder (3) is disposed between the outer protective sleeve (2) and the central tube (1), and the metal expandable outer cylinder (3) expands under the action of internal pressure to complete the setting. A cavity (31) is formed between the expandable metal outer cylinder (3) and the central tube (1). When the pressure inside the cavity (31) increases, it pushes the expandable metal outer cylinder (3) to expand. The cavity (31) is filled with hydraulic oil. An annular space (21) is provided between the outer protective sleeve (2) and the central tube (1), and the annular space (21) is connected to the cavity (31); an opening and closing mechanism (23) is provided in the annular space (21); the opening and closing mechanism (23) controls the liquid inlet (13) to be connected to the cavity (31) or disconnected from the cavity (31); The starting and stopping mechanism (23) includes a starting sleeve (24) and a stopping sleeve (25). When the starting sleeve (24) is started, the liquid inlet (13) is connected to the cavity (31); when the stopping sleeve (25) is started, the liquid inlet (13) is disconnected from the cavity (31). The starting sleeve (24) is located below the closing sleeve (25) and close to the cavity (31); and the starting sleeve (24) is connected to the outer protective sleeve (2) by a starting pin (26). The closing sleeve (25) is provided with a liquid guiding hole (28). In the initial state, the liquid guiding hole (28) is connected to the liquid inlet hole (13), and the closing sleeve (25) is connected to the outer protective sleeve (2) by a closing pin (27). After the closing pin (27) is disconnected, the liquid guiding hole (28) and the liquid inlet hole (13) are misaligned, so that the liquid inlet hole (13) is disconnected from the cavity (31). In the initial position, the closing sleeve (25) has a certain distance from the upper end of the annular space (21), forming a moving space (22). After the closing pin (27) is disconnected, the closing sleeve (25) moves into the moving space (22) and disconnects the liquid inlet hole (13) from the cavity (31).

2. The expandable metal tube packer according to claim 1, characterized in that, The outer protective sleeve (2) has a through hole (29) at the position corresponding to the moving space (22).

3. The expandable metal tube packer according to claim 2, characterized in that, A filter screen is provided on the through hole (29).

4. The expandable metal tube packer according to claim 3, characterized in that, The outer wall of the expandable metal outer cylinder (3) is provided with several annular grooves, and an expandable metal ring (32) is provided in the annular grooves. The outer wall of the expandable metal ring (32) is provided with several serrated structures. Before the expandable metal outer cylinder (3) expands, the outer diameter of the expandable metal ring (32) is smaller than the outer diameter of the lower plug (4). After the expandable metal outer cylinder (3) expands, the outer diameter of the expandable metal ring (32) is larger than the outer diameter of the lower plug (4).

5. The expandable metal tube packer according to claim 4, characterized in that, The central tube (1) is provided with a limiting step (14) in the middle. After the starting pin (26) breaks, the starting sleeve (24) moves into the cavity (31) under the action of liquid pressure and falls on the limiting step (14).

6. The expandable metal tube packer according to claim 1, characterized in that, The upper end of the central tube (1) is provided with an upper connector (11) and the lower end is provided with a lower connector (12); the inner side of the upper connector (11) is connected to the central tube (1) by a thread, and the outer side is connected to the outer protective sleeve (2) by a thread. The thickness of the upper connector (11) corresponds to the width of the annular space (21).

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