Tail pipe top packer

Abstract

The invention relates to a tail pipe top packer which comprises a mandrel and a setting mechanism arranged on the mandrel. The setting mechanism comprises a rubber sleeve arranged on the mandrel, a compression sleeve and a supporting sleeve, the compression sleeve and the supporting sleeve are arranged at the two ends of the rubber sleeve, and protection rings are arranged between the rubber sleeve and the compression sleeve and between the rubber sleeve and the supporting sleeve. The protective ring is attached to the compression sleeve and the supporting sleeve, so that the protective ring can deform together with the rubber barrel when the compression sleeve and the supporting sleeve extrude the rubber barrel. In this way, the protection ring and the rubber sleeve can be jointly attached to the inner wall of the casing pipe after setting, so that no gap exists between the protection ring and the casing pipe, the rubber sleeve is prevented from being sheared and torn by the protection ring under the action of axial pressure, and the pressure resistance and the sealing effect of the packer are improved.

Description

Technical Field

[0001] This invention relates to the field of packer technology, and more specifically to a tailpipe top packer. Background Technology

[0002] Packers are core tools in petroleum engineering for isolating producing and non-producing layers (interlayer), controlling pressure, and optimizing production. Their performance directly affects cementing quality, operational safety, and well lifespan. With the advancement of unconventional oil and gas development (such as shale gas and tight oil), packer technology is evolving towards higher temperatures, higher pressures, and higher reliability. Packers can be classified into two types based on their mechanism of action: compression packers and expansion packers.

[0003] Currently, compression packers have anti-surge rings at both ends of the rubber sleeve. However, after the rubber sleeve is set, the anti-surge ring will create a gap between itself and the sleeve, which can easily cause the pressure-bearing rubber sleeve to tear, thus significantly reducing the packer's pressure resistance and sealing performance. Summary of the Invention

[0004] In view of the above-mentioned problems in the prior art, the present invention provides a packer at the top of the tailpipe, which can effectively prevent the rubber sleeve from tearing under pressure, thereby greatly improving the pressure resistance and sealing performance of the packer.

[0005] A first aspect of the present invention provides a tailpipe top packer, comprising a mandrel and a setting mechanism disposed on the mandrel. The setting mechanism includes a rubber sleeve disposed on the mandrel, and compression sleeves and support sleeves disposed at both ends of the rubber sleeve, wherein a protective ring is disposed between the rubber sleeve and the compression sleeves and support sleeves. The protective ring is in contact with the compression sleeves and support sleeves so that the protective ring can deform together with the rubber sleeve when the compression sleeves and support sleeves compress the rubber sleeve.

[0006] Furthermore, the protective ring includes a first ring portion disposed on the first mounting portion of the rubber tube, and a second ring portion connected to the first ring portion. The second ring portion is disposed between the second mounting portion of the rubber tube and the compression sleeve and the support sleeve, so as to press the end of the rubber tube.

[0007] Furthermore, the compression sleeve and the support sleeve are provided with set screws, and the protective ring is made of soft metal material so that the set screws can compress and deform the protective ring after being tightened, thereby compressing the rubber cylinder and thus achieving axial fixation of the rubber cylinder.

[0008] Furthermore, the first ring portion is configured to deform together with the rubber sleeve during setting, so as to conform to the inner wall of the sleeve together with the rubber sleeve.

[0009] Furthermore, the outer diameter of the protective ring is not greater than the outer diameter of the rubber tube.

[0010] Furthermore, the thickness of the first ring portion is equal to the difference between the outer diameter of the body of the rubber tube and the outer diameter of the first mounting portion.

[0011] Furthermore, the outer diameter of the second mounting portion is smaller than the outer diameter of the first mounting portion, so that a stepped surface that can abut against the compression sleeve and the support sleeve is formed between the first mounting portion and the second mounting portion.

[0012] Furthermore, the protective ring also includes a connecting portion disposed between the first ring portion and the second ring portion, the connecting portion being fitted to the stepped surface.

[0013] Furthermore, a support ring is provided between the rubber tube and the mandrel to support the rubber tube in a radially outward direction.

[0014] Furthermore, a sealing ring is provided between the support ring and the mandrel.

[0015] The beneficial effects of this invention are as follows: This invention provides a tailpipe top packer, comprising a mandrel and a setting mechanism disposed on the mandrel. The setting mechanism includes a rubber sleeve disposed on the mandrel, and compression sleeves and support sleeves disposed at both ends of the rubber sleeve. A protective ring is disposed between the rubber sleeve and the compression sleeves and support sleeves. The protective ring fits snugly against the compression sleeves and support sleeves so that it deforms along with the rubber sleeve when the compression sleeves and support sleeves compress it. In this way, the protective ring and the rubber sleeve can fit together against the inner wall of the sleeve after setting, eliminating gaps between the protective ring and the sleeve. This prevents the rubber sleeve from being sheared and torn by the protective ring under axial pressure, improving the pressure resistance and sealing effect of the packer. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0017] Figure 1 The diagram shows a structural schematic of a top packer for a tailpipe.

[0018] Figure 2 As shown Figure 1 A partially enlarged view of the packer at the top of the tailpipe.

[0019] Figure 3 As shown Figure 1 The diagram shows the structure of the top packer of the tailpipe when it is not set in the casing.

[0020] Figure 4 As shown Figure 1The diagram shows the structure of the top packer of the tailpipe after it has been set in the sleeve.

[0021] In the figure, the following labels are used: 100, mandrel; 101, limiting groove; 200, setting mechanism; 300, sleeve; 301, flow channel; 10. Glue tube; 11. Body; 12. First mounting part; 13. Second mounting part; 14. Support ring; 15. Protective ring; 151. First ring part; 152. Second ring part; 153. Connecting part; 20. Compression sleeve; 21. Shear pin; 30. Support sleeve; 31. Receiving groove; 40. Set screw; 50. Limiting component; 60. Straightening ring; 61. Straightening block. Detailed Implementation

[0022] To make the technical problem to be solved, the technical solution, and the beneficial effects of this invention clearer, the invention will now be described in detail with reference to the accompanying drawings. This drawing is a simplified schematic diagram, illustrating only the basic structure of the invention, and therefore only shows the components relevant to the invention. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0023] refer to Figure 1 As shown, the tailpipe top packer provided by the present invention includes a mandrel 100 and a setting mechanism 200 disposed on the mandrel 100. The tailpipe top packer also includes a drive mechanism (not shown in the figure) disposed on the mandrel 100. The drive mechanism is configured to compress the setting mechanism 200 along the axial direction of the mandrel 100, so that the setting mechanism 200 expands in a radially outward direction, thereby setting the sleeve 300. It is readily understood that the drive mechanism can be a hydraulic mechanism, capable of using the pressure inside the mandrel 100 during pressing as the driving force. The drive mechanism can also be other mechanical structures capable of providing driving force. The specific structure of the drive mechanism is well known to those skilled in the art and will not be described in detail in this application.

[0024] Combination Figure 1-3As shown, in some embodiments, the setting mechanism 200 includes a rubber sleeve 10, and a compression sleeve 20 and a support sleeve 30 disposed at both ends of the rubber sleeve 10. The compression sleeve 20 is located between the rubber sleeve 10 and the drive mechanism, and is used to transmit the force applied by the drive mechanism to the rubber sleeve 10. The support sleeve 30 is fixed to the mandrel 100 to provide axial support to the rubber sleeve 10 when it is subjected to the compression of the compression sleeve 20, thereby allowing the rubber sleeve 10 to deform in a radially outward direction. The outer diameters of the rubber sleeve 10, the compression sleeve 20, and the support sleeve 30 are all smaller than the inner diameter of the casing 300, so that the setting mechanism 200 can form a flow channel 301 with the casing 300 during the process of being lowered into the well, allowing the drilling fluid to flow downhole. This can minimize the risk of collision between the setting mechanism 200 and the casing 300.

[0025] refer to Figure 2 As shown, in some embodiments, the rubber sleeve 10 includes a body 11, and a first mounting portion 12 and a second mounting portion 13 disposed at the end of the body 11. The first mounting portion 12 and the second mounting portion 13 are configured to mount a protective ring 15 to separate the rubber sleeve 10 from the compression sleeve 20 or the support sleeve 30. Furthermore, the first mounting portion 12 and the second mounting portion 13 are also configured to engage with the compression sleeve 20 and the support sleeve 30 so that the compression sleeve 20 and the support sleeve 30 limit the rubber sleeve 10 in the axial direction as well as in the radial direction, preventing axial displacement of the rubber sleeve 10 during tubing descent or downhole fluid circulation, thereby avoiding premature sealing due to accidents.

[0026] In some preferred embodiments, a support ring 14 is provided between the body 11 of the rubber sleeve 10 and the mandrel 100. The support ring 14 supports the rubber sleeve 10 in a radially outward direction, so that the body 11 of the rubber sleeve 10 can deform better in a radially outward direction during setting. Furthermore, the body 11 of the rubber sleeve 10 can still be press-fitted with the support ring 14 after deformation, thereby enhancing the sealing between the mandrel 100 and the setting mechanism 200, preventing fluid in the annular space from flowing between the mandrel 100 and the setting mechanism 200, thus improving the sealing effect of the packer. It should be understood that the support ring 14 is integrally formed with the mandrel 100, or it can be separately mounted on the mandrel 100. Preferably, a sealing ring can be provided between the mandrel 100 and the support ring 14, thereby further enhancing the sealing between the mandrel 100 and the setting mechanism 200.

[0027] In some preferred embodiments, the outer diameter of the first mounting portion 12 is smaller than the outer diameter of the body 11, so as not to increase the radial dimension of the setting mechanism 200 while installing the protective ring 15. The outer diameter of the second mounting portion 13 is smaller than the outer diameter of the first mounting portion 12, so that a stepped surface facing the axial direction is formed between the first mounting portion 12 and the second mounting portion 13. The second mounting portion 13 is located between the compression sleeve 20 and the mandrel 100, and between the support sleeve 30 and the mandrel 100. Furthermore, the ends of the compression sleeve 20 and the support sleeve 30 can abut against the stepped surface, so that the compression sleeve 20 and the support sleeve 30 not only limit the rubber sleeve 10 in the axial direction, but also, together with the mandrel 100, limit the rubber sleeve 10 in the radial direction, thereby reliably installing the rubber sleeve 10.

[0028] Combination Figure 2-4 As shown, in some embodiments, the protective ring 15 is a complete annular structure, including a first ring portion 151 disposed on the surface of the first mounting portion 12, a second ring portion 152 disposed on the surface of the second mounting portion 13, and a connecting portion 153 disposed between the first ring portion 151 and the second ring portion 152. The outer diameter of the protective ring 15 is not greater than the outer diameter of the rubber sleeve 10. Preferably, the thickness of the first ring portion 151 is equal to the difference between the outer diameters of the first mounting portion 12 and the body 11, so that when the first ring portion 151 is disposed on the surface of the first mounting portion 12, the outer surface of the first ring portion 151 can be flush with the outer surface of the body 11. In this way, the drilling fluid in the flow channel 301 can flow smoothly through the body 11 and the first ring portion 151. The first ring portion 151, the second ring portion 152, and the connecting portion 153 of the protective ring 15 fully protect the end of the rubber sleeve 10, prevent the rubber sleeve 10 from being scratched, and reduce the risk of premature expansion during packer insertion, circulation, and cementing. Furthermore, the protective ring 15 enables the compression sleeve 20 and the support sleeve 30 to effectively contact the rubber sleeve 10, so that the compression sleeve 20 and the support sleeve 30 can more effectively limit the rubber sleeve 10 in the axial and radial directions, thereby improving the installation reliability of the rubber sleeve 10.

[0029] In some embodiments, the second ring 152 may abut against the set screw 40 passing through the compression sleeve 20 and the support sleeve 30 to strengthen the connection between the rubber sleeve 10 and the compression sleeve 20 and the support sleeve 30. Furthermore, the second ring 152 isolates the set screw 40 from the rubber sleeve 10, preventing damage to the rubber sleeve 10 during installation of the set screw 40 and ensuring the integrity and strength of the rubber sleeve 10.

[0030] In some embodiments, the connecting portion 153 is fitted against the stepped surface to isolate the rubber sleeve 10 from the compression sleeve 20 and the support sleeve 30.

[0031] Combination Figure 3 and Figure 4As shown, in some preferred embodiments, the first ring portion 151 is configured to deform radially outward along with the rubber sleeve 10 during setting, so as to conform to the casing 300. In this way, there is no gap between the protective ring 15 and the casing 300 after setting. Therefore, the edge of the first ring portion 151 cannot shear the rubber sleeve 10 under pressure, avoiding tearing of the rubber sleeve 10, thereby significantly improving the pressure resistance and sealing performance of the setting mechanism 200. Furthermore, after deformation, the first ring portion 151 fully wraps around the end of the rubber sleeve 10, completely isolating the rubber sleeve 10 from the downhole environment, preventing direct contact between the rubber sleeve 10 and downhole gases or liquids that could affect its durability, thus effectively extending the service life of the rubber sleeve 10.

[0032] More preferably, the first ring portion 151 is made of a soft metal or alloy material with low yield strength and high ductility, such as aluminum or aluminum alloy. For the protective ring 15, only the first ring portion 151 may be made of a metal or alloy material with low yield strength and high ductility, while the connecting portion 153 and the second ring portion 152 may be made of a higher-strength metal material to better protect the rubber sleeve 10. It should be understood that the first ring portion 151, the connecting portion 153, and the second ring portion 152 of the protective ring 15 may also be made of the same soft metal material. In this way, when the set screw 40 is tightened on the compression sleeve 20 and the support sleeve 30, the set screw 40 can compress and slightly deform the protective ring 15, thereby causing the protective ring 15 to compress the rubber sleeve 10, thus achieving axial fixation of the rubber sleeve 10. The first ring portion 151, the connecting portion 153, and the second ring portion 152 may be connected by welding or integrally formed.

[0033] refer to Figure 1 As shown, in some embodiments, the compression sleeve 20 is connected to the mandrel 100 via a shear pin 21. Thus, the drive mechanism can only compress the rubber cartridge 10 through the compression sleeve 20 after the compression sleeve 20 has sheared the shear pin 21, thereby improving the setting conditions of the setting mechanism 200 and preventing accidental setting.

[0034] In some embodiments, a one-way limiting mechanism is also provided between the compression sleeve 20 and the mandrel 100. This one-way limiting mechanism is configured to allow the compression sleeve 20 to move only toward the rubber cylinder 10, thus preventing the compression sleeve 20 from moving away from the rubber cylinder 10 under the elastic force of the deformed rubber cylinder 10. This ensures that the setting mechanism 200 remains in a set state after setting, preventing accidental unsealing. Preferably, the one-way limiting mechanism can be a limiting snap ring and a snap ring groove disposed between the compression sleeve 20 and the mandrel 100. The specific arrangement of the limiting snap ring and the snap ring groove can be selected by those skilled in the art as needed, and will not be elaborated further in this application.

[0035] refer to Figure 1 and Figure 2 As shown, in some embodiments, the support sleeve 30 is mounted on the mandrel 100 by a limiting member 50. Specifically, the limiting member 50 is mounted in a limiting groove 101 on the mandrel 100 and protrudes from the outer surface of the mandrel 100. The support sleeve 30 and the straightening ring 60 together define a receiving groove 31 for accommodating the portion of the limiting member 50 protruding from the outer surface of the mandrel 100. In this way, the limiting member 50 provides axial restraint to the support sleeve 30 and the straightening ring 60, thereby mounting the support sleeve 30 on the mandrel 100 and enabling the support sleeve 30 to support the rubber sleeve 10 during setting. The support sleeve 30 and the straightening ring 60 can be connected by screws.

[0036] In some other embodiments not shown, the support sleeve 30 may also be mounted on the mandrel 100 by means of screwing, bolting or welding.

[0037] In some embodiments, the centralizing ring 60 is provided with a centralizing block 61, which is used to contact the casing 300 during the process of the packer being lowered downhole and set, and to play a centralizing role.

[0038] The following is combined with Figure 1-4 This application provides a detailed description of the setting process of the setting mechanism 200 and the packer provided in this application.

[0039] After the packer is installed on the tubing string, it is lowered to the target position downhole. The drive mechanism, after shearing the shear pin 21, pushes the compression sleeve 20 towards the rubber sleeve 10. During this process, the support sleeve 30 mounted on the mandrel 100 provides axial upward support to the rubber sleeve 10. Thus, the compression sleeve 20 and the support sleeve 30 together compress the rubber sleeve 10, causing the body 11 and the first mounting portion 12 of the rubber sleeve 10 to deform radially outward. The first ring portion 151 of the protective ring 15 deforms radially outward along with the first mounting portion 12 of the rubber sleeve 10 until the first ring portion 151 of the protective ring 15 and the body 11 of the rubber sleeve 10 abut against the inner wall of the casing 300, thereby completing the setting.

[0040] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0041] It should be understood that the terms "length", "width", "up", "down", "front and back", "left and right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0042] Although the invention has been described with reference to preferred embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner as long as there is no structural conflict. The invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A tailpipe top packer, comprising, mandrel (100); and A setting mechanism (200) is provided on the mandrel (100). The setting mechanism (200) includes a rubber sleeve (10) provided on the mandrel (100), and a compression sleeve (20) and a support sleeve (30) provided at both ends of the rubber sleeve (10). A protective ring (15) is provided between the rubber sleeve (10) and the compression sleeve (20) and the support sleeve (30). in, The protective ring (15) fits into the compression sleeve (20) and the support sleeve (30) so that the protective ring (15) can deform together with the rubber tube (10) when the compression sleeve (20) and the support sleeve (30) squeeze the rubber tube (10).

2. The tailpipe top packer according to claim 1, characterized in that, The protective ring (15) includes a first ring portion (151) disposed on the first mounting portion (12) of the rubber tube (10), and a second ring portion (152) connected to the first ring portion (151). The second ring portion (152) is disposed between the second mounting portion (13) of the rubber tube (10) and the compression sleeve (20) and the support sleeve (30) to press the end of the rubber tube (10).

3. The tailpipe top packer according to claim 2, characterized in that, Set screws (40) are provided on the compression sleeve (20) and the support sleeve (30). The protective ring (15) is made of soft metal material so that the set screws (40) can be tightened and deformed after tightening, thereby squeezing the rubber tube (10) and thus achieving axial fixation of the rubber tube (10).

4. The tailpipe top packer according to claim 2, characterized in that, The first ring portion (151) is configured to deform together with the rubber sleeve (10) during setting so as to conform together with the rubber sleeve (10) to the inner wall of the sleeve (300).

5. The tailpipe top packer according to claim 2, characterized in that, The outer diameter of the protective ring (15) is not greater than the outer diameter of the rubber tube (10).

6. The tailpipe top packer according to claim 5, characterized in that, The thickness of the first ring portion (151) is equal to the difference between the outer diameter of the body (11) of the rubber tube (10) and the outer diameter of the first mounting portion (12).

7. The tailpipe top packer according to claim 2, characterized in that, The outer diameter of the second mounting part (13) is smaller than the outer diameter of the first mounting part (12) so that a stepped surface that can abut against the compression sleeve (20) and the support sleeve (30) is formed between the first mounting part (12) and the second mounting part (13).

8. The tailpipe top packer according to claim 7, characterized in that, The protective ring (15) further includes a connecting portion (153) disposed between the first ring portion (151) and the second ring portion (152), the connecting portion (153) fitting the step surface.

9. The tailpipe top packer according to any one of claims 1-8, characterized in that, A support ring (14) is provided between the rubber tube (10) and the mandrel (100) for supporting the rubber tube (10) in a radially outward direction.

10. The tailpipe top packer according to claim 9, characterized in that, A sealing ring is provided between the support ring (14) and the mandrel (100).

Images