A combined rubber sleeve and packer

Abstract

The utility model relates to a combined rubber sleeve and packer belongs to downhole packer structure field, combined rubber sleeve includes: middle rubber sleeve and two end rubber sleeves that symmetrically are equipped with both ends thereof, and middle rubber sleeve and end rubber sleeve are all set up the outside of same center tube, and the both ends of middle rubber sleeve are equipped with the first rubber sleeve that extends along the axial direction, and the both ends of end rubber sleeve are equipped with the second rubber sleeve that extends along the axial direction, and the both ends of middle rubber sleeve are equipped with the first rubber sleeve that extends along the axial direction, and the both ends of end rubber sleeve are equipped with the second rubber sleeve that extends along the axial direction, and the both ends of middle rubber sleeve are equipped with the first rubber sleeve that extends along the axial direction, and the both ends of end rubber sleeve are equipped with the second rubber sleeve that extends along the axial direction, and the both ends of middle rubber sleeve are equipped with the first rubber sleeve that extends along the axial direction and the second rubber sleeve that extends along the axial direction, and the both ends of end rubber sleeve are equipped the second rubber sleeve that extends along the axial direction, and the both ends of middle rubber sleeve and end rubber sleeve are equipped with the inner bushing, and the inner bushing is rigid structure, and the coaxial sleeve is equipped on the center tube, and the both ends of inner bushing are respectively threaded in the first rubber sleeve and the second rubber sleeve, and the outer wall of inner bushing and the inner wall of first rubber sleeve and second rubber sleeve contact, and the length of inner bushing is less than the length of first rubber sleeve and the length of second rubber sleeve. The packer includes the combined rubber sleeve. The combined rubber sleeve in scheme has better sealing property and pressure bearing capacity, and it is helpful to improve the sealing effect of packer.

Description

Technical Field

[0001] This invention belongs to the field of downhole packer structure, and particularly relates to a combined rubber sleeve and packer. Background Technology

[0002] In downhole equipment for oil and gas wells, packers are commonly used downhole sealing tools. Packers mainly consist of a central tube, slips, and a rubber sleeve. During sealing, the slips are driven hydraulically or mechanically to move towards the inner wall of the casing, and the teeth on the outer surface of the slips engage with the inner wall of the casing to achieve mounting. Then, the rubber sleeve is driven mechanically or hydraulically to compress axially. Because the rubber sleeve is fitted outside the central tube, it cannot expand inward when compressed axially, so it can only expand outward. The outer wall of the rubber sleeve contacts the inner wall of the casing to form a sealing structure, thereby achieving the purpose of mounting.

[0003] To improve the sealing effect of the rubber sleeve and increase its ability to withstand axial loads, existing technologies typically employ a combined rubber sleeve structure. This involves designing multiple rubber sleeves arranged axially to form multiple sealing surfaces with the casing. For example, Chinese patent application number 202410909220.X discloses a combined sealing assembly consisting of a first end rubber sleeve, a middle rubber sleeve, and a second end rubber sleeve. This assembly can achieve strong resistance to bidirectional pressure differential under extreme well conditions such as high temperature and high pressure, and exhibits good temperature resistance, pressure resistance, and stability. However, in this design, the three rubber tubes are in direct contact with each other. Although the extended overall length of the tubes seems to increase the range of the sealing surface, since all the tubes are made of rubber, the outward expansion cross-section under axial pressure is uncontrollable after the length is extended. It is impossible for the tubes to expand outward accurately at the same cross-section, making it difficult to form a complete closed annular sealing structure, thus reducing the sealing effect and pressure resistance. Although this design sets both ends of the middle tube as outwardly extending conical structures, the conical surfaces at both ends of the middle tube are intended to compress the tubes at both ends to expand outward. However, since the middle tube itself is a compressible material, it is also impossible to accurately and evenly expand the tubes at both ends outward along the circumference. This easily leads to uneven stress on the sealing surface formed by the two tubes around the circumference, and leakage is likely to occur in areas with lower stress. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a combined rubber sleeve and packer. The combined rubber sleeve has better sealing performance and pressure resistance, which helps to improve the sealing effect of the packer.

[0005] In order to achieve the objective of this invention, the following solution is proposed:

[0006] A combined rubber sleeve includes: a central rubber sleeve and two end rubber sleeves symmetrically disposed at both ends of the central rubber sleeve, both the central rubber sleeve and the end rubber sleeves being sleeved on the outside of the same central tube. Each end of the central rubber sleeve has a first rubber sleeve extending axially at its outer edge, and each end rubber sleeve has a second rubber sleeve extending axially at its outer edge facing the central rubber sleeve.

[0007] An inner bushing is provided between the middle rubber tube and the end rubber tube. The inner bushing is a rigid structure and is coaxially sleeved on the central tube. The two ends of the inner bushing pass through the first rubber sleeve and the second rubber sleeve respectively, and the outer wall of the inner bushing contacts the inner wall of the first rubber sleeve and the second rubber sleeve. The length of the inner bushing is less than the sum of the lengths of the first rubber sleeve and the second rubber sleeve. The length of the first rubber sleeve refers to the dimension of its protrusion from the end face of the middle rubber tube, and the length of the second rubber sleeve refers to the dimension of its protrusion from the end face of the end rubber tube.

[0008] Packers, including the aforementioned combined rubber sleeve.

[0009] The beneficial effects of this invention are as follows: This solution forms a multi-ring sealing structure by using three rubber tubes, and the adjacent rubber tubes have better sealing performance, which not only helps to improve the overall sealing performance of the packer, but also effectively improves the load-bearing capacity of the rubber tubes. Attached Figure Description

[0010] The accompanying drawings described herein are merely illustrative of selected embodiments, not all possible implementations, and are not intended to limit the scope of the invention.

[0011] Figure 1 A cross-sectional view of the assembled rubber cartridge of this application is shown.

[0012] The markings in the diagram are: middle rubber tube-1, first rubber sleeve-11, annular groove-12, end rubber tube-2, second rubber sleeve-21, central tube-3, inner liner-4, sealing ring-41, inner gasket-5, inner ring-6, and outer ring-7. Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the implementation methods of the present invention will be described in detail below with reference to the accompanying drawings. However, the embodiments described in this invention are only some embodiments of the present invention, and not all embodiments.

[0014] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0015] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use, and are only for the convenience of describing the invention and simplifying the description. The terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance. The terms "parallel," "vertical," etc., do not mean that the components are required to be absolutely parallel or perpendicular, but can be slightly tilted.

[0016] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" 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 direct connection, an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0017] Example 1

[0018] like Figure 1 As shown, a combined rubber tube includes: a middle rubber tube 1 and two end rubber tubes 2 symmetrically disposed at both ends thereon, wherein the middle rubber tube 1 and the end rubber tubes 2 are both sleeved on the outside of the same central tube 3.

[0019] Specifically, such as Figure 1 As shown, the outer edges of both ends of the middle rubber cylinder 1 are provided with a first rubber sleeve 11 extending axially, and the outer edges of the end rubber cylinder 2 facing the middle rubber cylinder 1 are provided with a second rubber sleeve 21 extending axially. Specifically, the first rubber sleeve 11 is integrally formed with the middle rubber cylinder 1, and the second rubber sleeve 21 is integrally formed with the end rubber cylinder 2.

[0020] Specifically, such as Figure 1 As shown, an inner bushing 4 is provided between the middle rubber cylinder 1 and the end rubber cylinder 2. The inner bushing 4 is a rigid structure, made of metal materials such as iron, stainless steel, aluminum, or alloy structural steel, and is coaxially sleeved on the central tube 3. Preferably, as shown... Figure 1 As shown, a sealing ring 41 is embedded in the inner wall of the inner liner 4 to prevent leakage between the inner liner 4 and the central tube 3.

[0021] Specifically, such as Figure 1As shown, the inner sleeve 4 is inserted into the first rubber sleeve 11 and the second rubber sleeve 21 at both ends, and the outer wall of the inner sleeve 4 is in contact with the inner wall of the first rubber sleeve 11 and the second rubber sleeve 21. The length of the inner sleeve 4 is less than the sum of the lengths of the first rubber sleeve 11 and the second rubber sleeve 21. The length of the first rubber sleeve 11 refers to the size of its protrusion from the end face of the middle rubber cylinder 1, and the length of the second rubber sleeve 21 refers to the size of its protrusion from the end face of the end rubber cylinder 2.

[0022] When using the above-mentioned method for sealing, the packer applies pressure to both ends of the combined rubber cylinders via hydraulic or mechanical means, causing the two end rubber cylinders 2 to compress towards the middle rubber cylinder 1. Initially, because the length of the inner sleeve 4 is less than the sum of the lengths of the first rubber sleeve 11 and the second rubber sleeve 21, the end faces of the first rubber sleeve 11 and the second rubber sleeve 21 will contact each other first. Since the inner sleeve 4 is located inside the first rubber sleeve 11 and the second rubber sleeve 21, the thickness of the first rubber sleeve 11 and the second rubber sleeve 21 is less than that of the end rubber cylinders 2 and the middle rubber cylinder 1. During continued pressure application, the end faces of the first rubber sleeve 11 and the second rubber sleeve 21 will expand outwards circumferentially, forming the first annular sealing structure and creating an integral sealing structure between the central rubber cylinder 1 and the two end rubber cylinders 2. During continued pressure application, after the two ends of the inner sleeve 4 abut against the end faces of the middle rubber cylinder 1 and the end rubber cylinders 2 respectively, the middle rubber cylinder 1 and the end rubber cylinders 2 will gradually compress axially. Because their inner walls are restricted by the central tube 3, the middle rubber cylinder... The central rubber cylinder 1 and the two end rubber cylinders 2 will expand outward. Although the central rubber cylinder 1 and the two end rubber cylinders 2 form an integral structure at this time, the adjacent structures are restricted by the inner bushing 4. The two ends of the central rubber cylinder 1 and the end rubber cylinders 2 can still withstand the same pressure. Moreover, the inner bushing 4 is rigid and can evenly transmit the force to the cross-section of the central rubber cylinder 1 on the circumference when it moves forward, ensuring that the central rubber cylinder 1 is subjected to uniform force. Its reaction force can also be evenly fed back to the end rubber cylinders 2 along the circumference, so that the central rubber cylinder 1 and the end rubber cylinders 2 expand outward evenly along the circumference. This helps the central rubber cylinder 1 and the end rubber cylinders 2 to form a complete annular sealing surface to ensure the sealing effect. At the same time, it can also avoid the phenomenon of uneven deformation and uneven force caused by direct contact between the end faces of the central rubber cylinder 1 and the end rubber cylinders 2. After the central rubber cylinder 1 and the end rubber cylinders 2 are compressed, they will each form an annular sealing structure. With the addition of the two annular sealing structures formed by the first rubber sleeve 11 and the second rubber sleeve 21, the entire combined rubber cylinder can form a five-annular sealing structure. Compared with the existing three-tube solution, it has more annular sealing structures and better sealing effect; between adjacent tubes, the first tube sleeve 11 and the second tube sleeve 21 form an independent annular sealing structure, which not only increases the number of annular seals, but also effectively ensures the sealing between adjacent tubes.

[0023] Preferred, such as Figure 1As shown, an inner gasket 5 is provided in the middle section of the inner wall of the middle rubber cylinder 1. The inner gasket 5 is a rigid structure and is made of metal materials such as iron, stainless steel, aluminum, or alloy structural steel. Its two outer walls are conical surfaces. When the middle rubber cylinder 1 is squeezed, the conical surfaces on both sides of the inner gasket 5 will cause the middle rubber cylinder 1 to expand outward from the middle position. No matter which end of the middle rubber cylinder 1 is squeezed, it can be ensured that the two ends of the middle rubber cylinder 1 are completely symmetrical, so that the expansion of the middle rubber cylinder 1 is always uniform, so as to provide reliable sealing performance.

[0024] Preferred, such as Figure 1 As shown, the end of the inner sleeve 4 facing the end rubber tube 2 has an outer conical surface structure, which can effectively guide the end rubber tube 2 to expand outward and form a balanced squeezing force on the end rubber tube 2 along the circumference, thereby improving the sealing effect of the end rubber tube 2.

[0025] Preferred, such as Figure 1 As shown, there is an annular groove 12 between the end face of the middle rubber cylinder 1 and the inner wall of the first rubber sleeve 11. The groove is filled with sealant. During the compression of the middle rubber cylinder 1, the space of the annular groove 12 is gradually compressed, and the sealant filled inside is pressed into the contact surface between the middle rubber cylinder 1 and the central tube 3 to improve the lubrication of the middle rubber cylinder 1 during the compression process, so that the middle rubber cylinder 1 can be compressed smoothly along the axial direction, making it easier for the middle rubber cylinder 1 to expand outward. On the other hand, during the compression process in the space of the annular groove 12, the range of the inner bushing 4 moving towards the middle of the middle rubber cylinder 1 will be further increased, thereby further squeezing the end face of the middle rubber cylinder 1 towards the middle of the middle rubber cylinder 1. This process correspondingly increases the length of the first rubber sleeve 11 protruding from the end face of the middle rubber cylinder 1, and further increases the volume of the first rubber sleeve 11 compressed, thereby helping to improve the sealing effect of the annular sealing structure formed by the first rubber sleeve 11 and the second rubber sleeve 21.

[0026] Further preferred, such as Figure 1 As shown, the cross-section of the annular groove 12 is a right-angled triangle structure, with the hypotenuse of the triangle corresponding to the end face of the middle rubber cylinder 1. This structure allows the middle rubber cylinder 1 to expand outward more easily during the extrusion of the annular groove 12, and the axial expansion range of the middle rubber cylinder 1 will also be further increased. The expansion range of the middle rubber cylinder 1 with this structure will cover the entire area between the two annular grooves 12, making the sealing surface of the middle rubber cylinder 1 larger and improving its sealing performance and pressure resistance.

[0027] Preferred, such as Figure 1 As shown, the outer end of the end tube 2 is provided with an inner ring 6 and an outer ring 7 in sequence. The contact surface between the inner ring 6 and the end tube 2 is an inner conical surface structure. This structure can effectively prevent the outer end of the end tube 2 from being crushed and broken, and helps to improve the pressure bearing capacity of the end tube 2. The outer ring 7 is used to improve the structural strength of the inner ring 6 and prevent local deformation of its circumference.

[0028] Further preferred, such as Figure 1 As shown, the contact surface between the outer ring 7 and the inner ring 6 is an inner conical surface structure. The wall thickness of the inner ring 6 is smaller than that of the outer ring 7. The outer ring 7 has multiple grooves along its circumference at the end facing the inner ring 6. The grooves penetrate the inner and outer sides of the outer ring 7. During sealing, the end sleeve 2 will expand outward due to the axial pressure. After expansion, it will compress the thinner inner ring 6 to deform, thus maintaining the protection of the outer end of the end sleeve 2. As the pressure increases, the squeezing force of the inner ring 6 on the outer ring 7 also gradually increases, causing the outer ring 7 to open along the grooves to maintain the support of the inner ring 6.

[0029] Example 2

[0030] A packer comprising a combined rubber tube as described in Example 1.

[0031] The above description is merely a preferred embodiment of the present invention and is not intended to be the only or limiting of the invention. Those skilled in the art should understand that various changes or equivalent substitutions made to the present invention without departing from its scope are all within the protection scope of the present invention.

Claims

1. A modular rubber sleeve, comprising: The middle rubber cylinder (1) and two end rubber cylinders (2) symmetrically arranged at both ends thereof are fitted on the outside of the same central tube (3). The middle rubber cylinder (1) and the end rubber cylinders (2) are both provided with a first rubber sleeve (11) extending axially at the outer edge of both ends of the middle rubber cylinder (1), and a second rubber sleeve (21) extending axially at the outer edge of the end of the end rubber cylinder (2) facing the middle rubber cylinder (1). An inner bushing (4) is provided between the middle rubber tube (1) and the end rubber tube (2). The inner bushing (4) is a rigid structure and is coaxially sleeved on the central tube (3). The two ends of the inner bushing (4) are respectively inserted into the first rubber sleeve (11) and the second rubber sleeve (21). The outer wall of the inner bushing (4) is in contact with the inner wall of the first rubber sleeve (11) and the second rubber sleeve (21). The length of the inner bushing (4) is less than the sum of the length of the first rubber sleeve (11) and the length of the second rubber sleeve (21). The end face of the middle rubber tube (1) and the inner wall of the first rubber sleeve (11) have an annular groove (12), which is used to fill the sealant. The cross-section of the annular groove (12) is a right-angled triangle structure, and the hypotenuse of the triangle corresponds to the end face of the middle rubber tube (1); The outer end of the end tube (2) is provided with an inner ring (6) and an outer ring (7) in sequence. The contact surface between the inner ring (6) and the end tube (2) is an inner conical surface structure. The contact surface between the outer ring (7) and the inner ring (6) is an inner conical surface structure. The wall thickness of the inner ring (6) is smaller than that of the outer ring (7). The outer ring (7) has multiple grooves along its circumference at one end facing the inner ring (6). The grooves penetrate the inner and outer sides of the outer ring (7).

2. The combined rubber sleeve according to claim 1, characterized in that, The inner wall of the middle rubber cylinder (1) is provided with an inner pad ring (5) in the middle section. The inner pad ring (5) is a rigid structure and its two outer walls are conical surfaces.

3. The combined rubber sleeve according to claim 1, characterized in that, The inner liner (4) has an outer conical surface structure at one end facing the end sleeve (2).

4. A combined rubber sleeve according to claim 1, characterized in that, The inner wall of the inner liner (4) is fitted with a sealing ring (41).

5. A packer, characterized in that, Includes the combined rubber cartridge as described in any one of claims 1 to 4.

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