Packer capable of being sleeved and milled
By using the upper and lower pressure cap made of composite materials and combining the O-ring and guide keys, the problem of unsealing of the packer due to casing corrosion and deformation is solved, and the efficient unsealing of the packer is achieved and improve construction safety.
Patent Information
- Application Number
- CN202421147678.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-24
- Publication Date
- 2025-01-03
- Estimated Expiration
- 2034-05-24
AI Technical Summary
During use, existing packers are prone to unsealing due to casing corrosion and deformation, resulting in high repair costs and difficult construction. The existing sleeve milling materials are not suitable for unsealing.
The upper and lower pressure caps made of composite materials can be easily and efficiently unsealed by grinding and milling of these materials. The O-ring and guide keys are combined to improve sealing and stability, and the inner diameter of the sleeve is adapted to Increase the probability of unblocking.
It realizes efficient unsealing of the packer, reduces the cost of well repair and construction difficulty, and improves construction safety and system reliability.
Smart Images
Figure CN222296181U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of oil field equipment, in particular to a millable packer. Background Art
[0002] The packer is a downhole tool used in oil fields in the field of oil production. Taking the Y111 packer as an example, this packer is a relatively simple compression packer. The specific structure includes an upper joint, a lower joint, a center pipe, a rubber tube assembly and an outer tube. The specific principle is: when there is support under the lower joint and provides sufficient pressure for the upper joint, the center pipe moves down with the upper joint. During this process, the lower part of the rubber tube assembly is directly or indirectly supported on the outer tube and keeps its position unchanged, and the upper part of the rubber tube assembly is pressed down with the movement of the upper joint. At this time, the rubber tube moves radially. The annular space around the packer is expanded and closed, thereby obtaining the sealing effect; the specific operation process and action process are as follows: after the packer is lowered to the designed position, the pipe string is lifted to a certain height, and then the pipe string is lowered. The lower pipe string of the packer is supported by external force, and part of the weight of the tubing first closes the packer bypass and then compresses the packer seal, so that the seal expands radially to achieve the purpose of sealing the annular space of the oil casing. When it is necessary to unseal, the pipe string is lifted, the packer bypass is opened first, the upper and lower parts of the packer are connected, the pressure is balanced, and the packer rubber cylinder is restored to its original state, and the packer can be taken out. This packer can be used for oil production, water injection, testing and production increase measures. When the pressure at the bottom of the packer is high, it must be used in conjunction with a hydraulic anchor.
[0003] In order to solve the problem that the packer may not be released normally during use, there are packer milling tools and packers that can be milled in the prior art. Specific technical solutions include the technical solutions provided by patent applications No. CN 200420030728.0 and CN201921919231.7 and the technical solution provided by patent application No. CN201420038614.4. The implementation of these technologies can realize the release and unblocking of the packer by post-milling, and at the same time has the characteristics of shortening the milling time and greatly improving the efficiency of deep well and complex well drilling and production development operations.
[0004] In view of the problem that the packer cannot be released normally, it is necessary to further optimize the structure of the packer. Utility Model Content
[0005] In order to further optimize the packer structure proposed above, the utility model provides a milling packer. The structural design adopted by the packer can optimize the probability of normal unsealing of the packer and the efficiency of milling unsealing.
[0006] In view of the above problems, the utility model provides a millable packer to solve the problems through the following technical points: a millable packer, comprising an upper joint, a center tube, an outer tube and a lower joint connected in sequence, and also comprising a rubber tube outermostly arranged on the center tube and located between the upper joint and the outer tube. The number of the rubber tubes is multiple, and spacer rings are arranged between adjacent rubber tubes. The utility model also comprises an upper pressure cap connected to the lower end of the upper joint by a connecting thread, and a lower pressure cap connected to the upper end of the outer tube by a connecting thread. The upper end of the rubber tube is connected to the lower end of the upper pressure cap, and the lower end of the rubber tube is connected to the upper end of the lower pressure cap. The outer diameter of the upper pressure cap is larger than the outer diameter of the upper joint, and the outer diameter of the lower pressure cap is larger than the outer diameter of the outer tube. The materials of the upper pressure cap, the spacer ring and the lower pressure cap are all composite materials.
[0007] In the middle and late stages of oilfield development, the casing in the oil well or water injection well will corrode and possibly deform due to long-term corrosion from underground media and the influence of formation forces, making it impossible for the rubber tube sealed by the packer on the casing to be released normally. On the Y111 packer, in order to make the upper end of the uppermost rubber tube and the lower end of the lowermost rubber tube have a larger contact area, an upper pressure cap whose lower end face contacts the rubber tube is usually provided above the rubber tube, and a lower pressure cap whose upper end face contacts the rubber tube is provided below the rubber tube. At the same time, based on the structural characteristics of the packer, the upper pressure cap usually uses the upper joint as a mounting seat, and the lower pressure cap usually uses the outer tube as a mounting seat. Under such a packer structure, in the length direction of the packer, the positions of the upper pressure cap, the rubber tube and the lower pressure cap are where the packer has a larger diameter. In the scheme of millable packers, usually only the rubber cylinder and the spacer ring are set to be made of composite materials so that milling can be carried out to avoid major repairs when the packer cannot be unsealed normally. However, in specific applications, if the upper and lower pressure caps of the packer are made of steel materials, when they are squeezed or deformed under extrusion, because their outer diameters themselves are closer to the inner diameter of the casing, the upper and lower pressure caps are prone to get stuck on the casing wall. The existing upper and lower pressure cap materials are not suitable for milling with milling pipes. In order to unblock and unseal the packer, a major repair is required, which not only increases the cost of well repair, but also makes the construction difficult and time-consuming. Based on this, a millable packer as described above is proposed. When the packer cannot be unsealed normally, the composite material can be milled off to efficiently complete the unsealing of the packer.
[0008] In the above scheme, the relative positions of the upper joint and the central tube of the packer are fixed during the entire use period, and the relative positions of the outer tube and the lower joint are fixed. If the shear nails between the central tube and the outer tube are cut off under the pressure from above, the central tube slides downward along the outer tube. At this time, the lower end of the rubber tube is supported by the lower pressure cap, and the upper end is squeezed by the upper pressure cap. After radial deformation, the surrounding annular space is sealed. At the same time, the threaded connection between the upper joint and the upper pressure cap is suitable for the connection between dissimilar materials, and specifically, the connection position of the center tube on the upper joint is located on the inner side of the lower end of the upper joint, and the connection position of the upper pressure cap on the upper joint is located on the outer side of the lower end of the upper joint. The inner side of the outer tube is used to cooperate with the center tube. The threaded connection between the outer tube and the lower pressure cap is suitable for the connection of dissimilar materials, and the connection position on the outer tube is located on the outer side of the upper end of the outer tube. In this way, the packer can be simply set to have an outer diameter of the upper pressure cap larger than the outer diameter of the upper joint, and an outer diameter of the lower pressure cap larger than the outer diameter of the outer tube, so that the packer as a whole is adapted to the position with larger diameters located at the position of the upper pressure cap, the position of the rubber tube and the position of the lower pressure cap. The outer diameters of these positions are closer to the inner diameter of the casing, so these positions have a greater probability of being stuck on the casing wall. On the basis that the materials of the upper pressure cap, the spacer ring and the lower pressure cap are all composite materials, the packer can be unsealed by grinding off the composite materials.
[0009] For the packer with the maximum composite material outer diameter of φ115 (the outer diameter of the upper pressure cap and the lower pressure cap is φ115) and the maximum steel outer diameter of φ93 (the outer diameter of the upper joint, the lower joint and the outer tube is φ93), the inner diameter of the milling tube is φ95-100. The specific unpacking method can be: the packer can directly use the alloy milling tube with an outer diameter of φ118 and an inner diameter of φ95 to mill the outer layer of the composite material of the packer. After completing the full-length milling operation of the packer, the stuck point of the packer can be quickly released, so that the packer can be smoothly removed from the well.
[0010] In summary, this solution provides a technical solution in which the radial extrusion position of the packer on the casing wall is more likely to be located at the upper pressure cap, the rubber sleeve and the lower pressure cap. When the packer is stuck at these positions during use, a more convenient and efficient sleeve milling solution can be adopted to remove the stuck points compared to overhaul, so that the packer can be unsealed smoothly and efficiently.
[0011] At the same time, compared with steel upper pressure cap, spacer ring and lower pressure cap, the upper pressure cap, spacer ring and lower pressure cap made of composite materials have stronger elastic deformation ability. When these components are moved out to the non-deformed area of the casing, the stuck point can be removed by these components restoring their shape by themselves. Therefore, the above scheme makes it more likely that the packer can be normally unsealed.
[0012] In a specific embodiment, the upper joint, center tube, outer tube and lower joint are all metal tubes, the inner side of the lower end of the upper joint is threadedly connected to the outer side of the upper end of the center tube, the lower end of the center tube is embedded in the inner side of the outer tube, and a shear pin for limiting the axial position of the outer tube in the center tube is also provided between the center tube and the outer tube, and positioning steps are provided on the outer side of the lower end of the center tube and the inner side of the middle section of the outer tube. When the shear pin is not sheared off, the positioning step on the center tube contacts the positioning step on the outer tube, and the positioning step prevents the outer tube from sliding downward relative to the center tube. The inner side of the lower end of the outer tube is threadedly connected to the outer side of the upper end of the lower joint.
[0013] In the above scheme, before the packer is set, the connecting threads between the upper joint and the center tube, the shear pins between the center tube and the outer tube, the positioning steps, and the connecting threads between the outer tube and the lower joint enable the relevant components to be connected to form a fixed-length main structure on the packer. When the pipe column connected to the upper joint is lowered, the support of the positioning steps on the center tube to the positioning steps on the outer tube can reduce the force on the shear pins, so that the above subject structure is maintained in a stable form to facilitate the installation of the packer. Due to the presence of the positioning steps, smaller shear pins can be used to facilitate the shearing of the shear pins when the packer is set. In order to ensure a reliable sealing effect between the inner space of the packer and the outer annular space, a further application is: the upper joint and the center tube are connected by pipe threads, and the lower joint and the outer tube are connected by pipe threads. For the center tube and the outer tube that slide relative to each other during use, O-rings are set between the lower pressure cap and the center tube and between the lower pressure cap and the outer tube.
[0014] In a specific embodiment, the positioning step on the outer side of the lower end of the central tube is provided by a nut threadedly connected to the lower end of the central tube, and the positioning step is the upper end surface of the nut.
[0015] The above scheme provides a scheme that is convenient for processing the center tube. Specifically, when processing the tubular center tube, there is no need to consider that there is material for forming the positioning step at the lower end of the center tube. Instead, after the center tube is processed, the nut is connected by threading and the positioning step is formed using the upper end surface of the nut. As for the positioning step on the outer tube, the step surface located on the inner side of the outer tube can be formed by removing material from the lower end of the outer tube to the inner side of the outer tube. The step surface serves as the positioning step.
[0016] In a specific embodiment, O-rings are provided between the pressing cap and the central tube and between the pressing cap and the outer tube.
[0017] As described above, the present solution provides a technical solution that utilizes an O-ring between the pressure cap and the center tube to solve the axial leakage that may occur between the pressure cap and the center tube, and utilizes an O-ring between the pressure cap and the outer tube to solve the axial leakage that may occur between the pressure cap and the outer tube, so that the inside and outside of the isolation device have reliable sealing.
[0018] The upper pressure cap and the lower pressure cap mentioned above are cap-shaped structures, specifically: the upper pressure cap and the lower pressure cap both include a barrel portion and an annular boss located at the end of the barrel portion, and a hole is provided between the annular bosses for the central tube to pass through. The barrel portion on the upper pressure cap is threadedly connected to the upper joint, and the annular boss on the upper pressure cap is clamped between the upper end of the rubber tube and the lower end of the upper joint. Similarly, the barrel portion on the lower pressure cap is threadedly connected to the upper end of the outer tube, and the annular boss on the lower pressure cap is clamped between the lower end of the rubber tube and the upper end of the outer tube. The O-ring between the lower pressure cap and the central tube is arranged on the inner wall of the annular boss of the lower pressure cap, and the O-ring between the lower pressure cap and the outer tube is arranged on the inner wall of the barrel portion.
[0019] In a specific embodiment, a guide key is further provided between the central tube and the outer tube.
[0020] In the above scheme, the guide key can be a flat key, which can avoid relative rotation between the central tube and the outer tube by bearing shear stress, which is beneficial to the structural stability and reliability of the isolation.
[0021] In a specific embodiment, the composite material is a fiber reinforced epoxy resin composite material.
[0022] In the prior art, composite materials are commonly used in packers. Compared with traditional materials (such as metal materials), composite materials are lighter, which helps to reduce the overall weight of the packer and improve the system operation efficiency and reliability. At the same time, under the premise of ensuring strength, because the composite materials are easy to be milled, the corresponding jam position can be milled out when the packer is stuck, which increases the construction safety and reduces the cost and failure time during the construction process. In this scheme, fiber-reinforced epoxy resin composite materials are used. This material is an existing material, that is, this scheme does not involve the improvement of the material. At the same time, the mechanical performance index of fiber-reinforced epoxy resin composite materials is 15-20% higher than that of conventional composite materials, so as to improve the strength and durability of the packer. At the same time, it is a composite material with excellent strength-to-weight ratio and corrosion resistance, which can withstand high pressure and harsh working environment.
[0023] In a specific embodiment, the fiber reinforced epoxy resin composite material is a composite material added with nano metal.
[0024] In the prior art, composite materials with nano-metals distributed on fibers are prior art, and the specific solution is provided in the patent application document with patent application number CN201910318846.2. Therefore, this solution only involves material selection and does not involve material improvement. At the same time, fiber-reinforced epoxy resin composite materials with nano-metals added have outstanding thermal conductivity and corrosion resistance. Such materials are more suitable for the working environment of the packer, so that related parts can remain reliable for a long time.
[0025] In a specific embodiment, both ends of each rubber tube are cone-shaped structures with an end diameter smaller than a middle diameter.
[0026] In the above scheme, the cone-shaped structures at both ends of each rubber tube can make the radial expansion of the rubber tube when the rubber tube is subjected to axial pressure obviously located in the middle of the rubber tube. This scheme is beneficial to the accuracy of the sealing position of the packer and the sealing reliability.
[0027] The utility model has the following beneficial effects:
[0028] This solution provides a technical solution in which the radial extrusion position of the packer on the casing wall is more likely to be located at the upper pressure cap, the rubber sleeve and the lower pressure cap. When the packer is stuck at these positions during use, a more convenient and efficient sleeve milling solution can be adopted to remove the stuck points compared to overhaul, so that the packer can be unsealed smoothly and efficiently.
[0029] At the same time, compared with steel upper pressure cap, spacer ring and lower pressure cap, the upper pressure cap, spacer ring and lower pressure cap made of composite materials have stronger elastic deformation ability. When these components are moved out to the non-deformed area of the casing, the stuck point can be removed by these components restoring their shape by themselves. Therefore, the above scheme makes it more likely that the packer can be normally unsealed. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Figure 1 It is a cross-sectional view of a specific embodiment of a millable packer described in this solution.
[0031] The reference numerals in the figure are: 1, upper joint, 2, upper pressure cap, 3, center tube, 4, rubber cylinder, 5, spacer ring, 6, O-ring, 7, lower pressure cap, 8, shear pin, 9, guide key, 10, outer tube, 11, nut, 12, screw, 13, lower joint. DETAILED DESCRIPTION
[0032] The present invention is further described in detail below in conjunction with the embodiments, but the present invention is not limited to the following embodiments:
[0033] Embodiment 1:
[0034] like Figure 1As shown, a sleeve-milling packer comprises an upper joint 1, a central tube 3, an outer tube 10 and a lower joint 13 connected in sequence, and also comprises a rubber tube 4 which is sleeved on the central tube 3 and located between the upper joint 1 and the outer tube 10. The number of the rubber tubes 4 is multiple, and spacer rings 5 are also arranged between adjacent rubber tubes 4. It also comprises an upper pressure cap 2 which is connected to the lower end of the upper joint 1 by a connecting thread, and a lower pressure cap 7 which is connected to the upper end of the outer tube 10 by a connecting thread. The upper end of the rubber tube 4 is connected to the lower end of the upper pressure cap 2, and the lower end of the rubber tube 4 is connected to the upper end of the lower pressure cap 7. The outer diameter of the upper pressure cap 2 is larger than the outer diameter of the upper joint 1, and the outer diameter of the lower pressure cap 7 is larger than the outer diameter of the outer tube 10. The materials of the upper pressure cap 2, the spacer ring 5 and the lower pressure cap 7 are all composite materials.
[0035] In the middle and late stages of oilfield development, the casing in the oil well or water injection well will corrode and possibly deform due to long-term corrosion from underground media and the influence of formation forces, making it impossible for the rubber tube 4 sealed on the casing by the packer to be released normally. On the Y111 packer, in order to make the upper end of the uppermost rubber tube 4 and the lower end of the lowermost rubber tube 4 have a larger contact area, an upper pressure cap 2 whose lower end face contacts the rubber tube 4 is usually provided above the rubber tube 4, and a lower pressure cap 7 whose upper end face contacts the rubber tube 4 is provided below the rubber tube 4. At the same time, based on the structural characteristics of the packer, the upper pressure cap 2 usually uses the upper joint 1 as a mounting seat, and the lower pressure cap 7 usually uses the outer tube 10 as a mounting seat. Under such a packer structure, in the length direction of the packer, the positions of the upper pressure cap 2, the rubber tube 4 and the lower pressure cap 7 are where the packer has a larger diameter. In the existing scheme of millable packers, usually only the rubber cylinder 4 and the spacer ring 5 are set to be made of composite materials so that milling can be carried out to avoid major repairs when the packer cannot be unsealed normally. However, in specific applications, if the upper pressure cap 2 and the lower pressure cap 7 of the packer are made of steel materials, when they are squeezed or deformed under squeezing, because their outer diameters themselves are closer to the inner diameter of the casing, the upper pressure cap 2 and the lower pressure cap 7 are prone to get stuck on the casing wall. The existing materials of the upper pressure cap 2 and the lower pressure cap 7 are not suitable for milling with milling pipes. If the packer is to be unstuck and unsealed, a major repair is required, which not only increases the cost of well repair, but also has great construction difficulty and a long time consumption. Based on this, a millable packer as described above is proposed. When the packer cannot be unsealed normally, the packer can be unsealed efficiently by milling off the composite material.
[0036] In the above scheme, the relative positions of the upper joint 1 and the central tube 3 are fixed during the entire use of the packer, and the relative positions of the outer tube 10 and the lower joint 13 are fixed. When the shear nails 8 between the central tube 3 and the outer tube 10 are cut off under the pressure from above, the central tube 3 slides downward along the outer tube 10. At this time, the lower end of the rubber tube 4 is supported by the lower pressure cap 7, and the upper end is squeezed by the upper pressure cap 2. After radial deformation, the surrounding annular space is sealed. At the same time, the threaded connection between the upper joint 1 and the upper pressure cap 2 is suitable for the connection between dissimilar materials, and specifically, the connection position of the center pipe 3 on the upper joint 1 is located on the inner side of the lower end of the upper joint 1, and the connection position of the upper pressure cap 2 on the upper joint 1 is located on the outer side of the lower end of the upper joint 1. The inner side of the outer tube 10 is used to cooperate with the center pipe 3. The threaded connection between the outer tube 10 and the lower pressure cap 7 is suitable for the connection of dissimilar materials, and the connection position on the outer tube 10 is located on the outer side of the upper end of the outer tube 10. In this way, the packer can be simply set to have an outer diameter of the upper pressure cap 2 larger than the outer diameter of the upper joint 1, and an outer diameter of the lower pressure cap 7 larger than the outer diameter of the outer tube 10, so that the packer as a whole is adapted to the position with a larger diameter located at the position of the upper pressure cap 2, the position of the rubber tube 4 and the position of the lower pressure cap 7. The outer diameters of these positions are closer to the inner diameter of the casing, so these positions have a greater probability of being stuck on the casing wall. On the basis that the materials of the upper pressure cap 2, the spacer ring 5 and the lower pressure cap 7 are all composite materials, the packer can be unsealed by milling off the composite materials.
[0037] For the packer with a maximum composite material outer diameter of φ115 (the outer diameters of the upper pressure cap 2 and the lower pressure cap 7 are φ115) and a maximum steel body diameter of φ93 (the outer diameters of the upper joint 1, the lower joint 13 and the outer tube 10 are φ93), the inner diameter of the milling tube is φ95-100. The specific unsealing method can be: the packer can directly use an alloy milling tube with an outer diameter of φ118 and an inner diameter of φ95 to mill the outer layer of the composite material of the packer. After completing the full-length milling operation of the packer, the stuck points of the packer can be quickly released, thereby achieving the purpose of smoothly removing the packer from the well.
[0038] In summary, this solution provides a technical solution in which the radial extrusion position of the packer on the casing wall is more likely to be located at the upper pressure cap 2, the rubber cylinder 4 and the lower pressure cap 7. When the packer is stuck at these positions during use, a more convenient and efficient sleeve milling solution can be adopted to remove the stuck points compared to overhaul, so that the packer can be unsealed smoothly and efficiently.
[0039] At the same time, compared with the steel upper pressure cap 2, spacer ring 5 and lower pressure cap 7, the upper pressure cap 2, spacer ring 5 and lower pressure cap 7 made of composite materials have stronger elastic deformation ability. When these components are moved out to the non-deformed area of the casing, the stuck points can be removed by self-restoring their shapes. Therefore, the above scheme makes it more likely that the sealer can be normally unsealed.
[0040] In a more detailed scheme, the upper joint 1, the center tube 3, the outer tube 10 and the lower joint 13 are all metal tubes. The inner side of the lower end of the upper joint 1 is threadedly connected to the outer side of the upper end of the center tube 3. The lower end of the center tube 3 is embedded in the inner side of the outer tube 10. A shear nail 8 for limiting the axial position of the outer tube 10 in the center tube 3 is also provided between the center tube 3 and the outer tube 10. Positioning steps are provided on the outer side of the lower end of the center tube 3 and the inner side of the middle section of the outer tube 10. When the shear nail 8 is not cut off, the positioning step on the center tube 3 contacts the positioning step on the outer tube 10. The positioning step prevents the outer tube 10 from sliding downward relative to the center tube 3. The inner side of the lower end of the outer tube 10 is threadedly connected to the outer side of the upper end of the lower joint 13.
[0041] In the above scheme, before the packer is set, the connection threads between the upper joint 1 and the central tube 3, the shear pins 8 between the central tube 3 and the outer tube 10, the positioning steps, and the connection threads between the outer tube 10 and the lower joint 13 make the relevant parts connected to form a fixed-length main structure on the packer. When the pipe string connected to the upper joint 1 is lowered, the support of the positioning steps on the central tube 3 to the positioning steps on the outer tube 10 can reduce the force on the shear pins 8, so that the above subject structure is maintained in a stable form to facilitate the installation of the packer. Due to the presence of the positioning steps, smaller shear pins 8 can be used to facilitate the shearing of the shear pins 8 when the packer is set. In order to ensure a reliable sealing effect between the inner space of the packer and the outer annular space, a further application is: the upper joint 1 and the central tube 3 are connected by pipe threads, and the lower joint 13 and the outer tube 10 are connected by pipe threads. For the central tube 3 and the outer tube 10 that slide relative to each other during use, O-rings 6 are set between the lower pressure cap 7 and the central tube 3 and between the lower pressure cap 7 and the outer tube 10.
[0042] In a more detailed solution, the positioning step on the outer side of the lower end of the central tube 3 is provided by a nut 11 threadedly connected to the lower end of the central tube 3 , and the positioning step is the upper end surface of the nut 11 .
[0043] The above scheme provides a scheme that is convenient for processing the center tube 3. Specifically, when processing the tubular center tube 3, it is not necessary to consider that there is material for forming the positioning step at the lower end of the center tube 3. Instead, after the center tube 3 is processed, the nut is connected by threading and the positioning step is formed using the upper end surface of the nut. As for the positioning step on the outer tube 10, the step surface located on the inner side of the outer tube 10 can be formed by removing material from the lower end of the outer tube 10 to the inner side of the outer tube 10. The step surface serves as the positioning step.
[0044] In a more detailed solution, O-rings 6 are provided between the pressing cap 7 and the central tube 3 and between the pressing cap 7 and the outer tube 10 .
[0045] As described above, the present solution provides a technical solution that utilizes the O-ring 6 between the pressure cap 7 and the center tube 3 to solve the axial leakage that may occur between the pressure cap 7 and the center tube 3, and utilizes the O-ring 6 between the pressure cap 7 and the outer tube 10 to solve the axial leakage that may occur between the pressure cap 7 and the outer tube 10, so that the inside and outside of the isolation device have reliable sealing.
[0046] The upper pressure cap 2 and the lower pressure cap 7 are cap-shaped structures, specifically: the upper pressure cap 2 and the lower pressure cap 7 both include a barrel portion and an annular boss located at the end of the barrel portion, and a hole is provided between the annular bosses for the central tube 3 to pass through. The barrel portion on the upper pressure cap 2 is threadedly connected to the upper joint 1, and the annular boss on the upper pressure cap 2 is clamped between the upper end of the rubber tube 4 and the lower end of the upper joint 1. Similarly, the barrel portion on the lower pressure cap 7 is threadedly connected to the upper end of the outer tube 10, and the annular boss on the lower pressure cap 7 is clamped between the lower end of the rubber tube 4 and the upper end of the outer tube 10. The O-ring 6 between the lower pressure cap 7 and the central tube 3 is arranged on the inner wall of the annular boss of the lower pressure cap 7, and the O-ring 6 between the lower pressure cap 7 and the outer tube 10 is arranged on the inner wall of the barrel portion.
[0047] In a more detailed solution, a guide key 9 is further provided between the central tube 3 and the outer tube 10 .
[0048] In the above scheme, the guide key 9 can be a flat key, which can avoid the relative rotation between the central tube 3 and the outer tube 10 by bearing the shear stress, which is beneficial to the structural stability and reliability of the packing.
[0049] In a more detailed embodiment, the composite material is a fiber-reinforced epoxy resin composite material.
[0050] In the prior art, composite materials are commonly used in packers. Compared with traditional materials (such as metal materials), composite materials are lighter, which helps to reduce the overall weight of the packer and improve the system operation efficiency and reliability. At the same time, under the premise of ensuring strength, because the composite materials are easy to be milled, the corresponding jam position can be milled out when the packer is stuck, which increases the construction safety and reduces the cost and failure time during the construction process. In this scheme, fiber-reinforced epoxy resin composite materials are used. This material is an existing material, that is, this scheme does not involve the improvement of the material. At the same time, the mechanical performance index of fiber-reinforced epoxy resin composite materials is 15-20% higher than that of conventional composite materials, so as to improve the strength and durability of the packer. At the same time, it is a composite material with excellent strength-to-weight ratio and corrosion resistance, which can withstand high pressure and harsh working environment.
[0051] In a more detailed solution, the fiber reinforced epoxy resin composite material is a composite material added with nano metal.
[0052] In the prior art, composite materials with nano-metals distributed on fibers are prior art, and the specific solution is provided in the patent application document with patent application number CN201910318846.2. Therefore, this solution only involves material selection and does not involve material improvement. At the same time, fiber-reinforced epoxy resin composite materials with nano-metals added have outstanding thermal conductivity and corrosion resistance. Such materials are more suitable for the working environment of the packer, so that related parts can remain reliable for a long time.
[0053] In a more detailed solution, both ends of each rubber tube 4 are cone-shaped structures with an end diameter smaller than a middle diameter.
[0054] In the above scheme, the cone-shaped structures at both ends of each rubber tube 4 can ensure that the radial expansion of the rubber tube 4 when the rubber tube 4 is subjected to axial pressure is obviously located in the middle of the rubber tube 4. This scheme is beneficial to the accuracy of the sealing position of the packer and the sealing reliability.
[0055] In a more detailed solution, in order to prevent the upper joint 1 from loosening with the central tube 3 and the outer tube 10 from loosening with the lower joint 13, screws 12 for preventing loosening can be provided between the upper joint 1 and the central tube 3 and / or between the outer tube 10 and the lower joint 13 as needed.
[0056] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and the specific embodiments of the present invention cannot be considered to be limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, other embodiments derived without departing from the technical solution of the present invention should be included in the protection scope of the present invention.
Claims
1. A millable packer, comprising an upper joint (1), a central tube (3), an outer tube (10) and a lower joint (13) connected in sequence, and also comprising a rubber tube (4) which is sleeved on the central tube (3) and located between the upper joint (1) and the outer tube (10), wherein the number of the rubber tubes (4) is plural, and a spacer ring (5) is further arranged between adjacent rubber tubes (4), characterized in that: It also includes an upper pressure cap (2) connected to the lower end of the upper joint (1) through a connecting thread, and a lower pressure cap (7) connected to the upper end of the outer tube (10) through a connecting thread. The upper end of the rubber tube (4) is connected to the lower end of the upper pressure cap (2), and the lower end of the rubber tube (4) is connected to the upper end of the lower pressure cap (7). The outer diameter of the upper pressure cap (2) is greater than the outer diameter of the upper joint (1), and the outer diameter of the lower pressure cap (7) is greater than the outer diameter of the outer tube (10). The materials of the upper pressure cap (2), the spacer ring (5) and the lower pressure cap (7) are all composite materials.
2. A millable packer according to claim 1, characterized in that: The upper joint (1), the center tube (3), the outer tube (10) and the lower joint (13) are all metal tubes. The inner side of the lower end of the upper joint (1) is threadedly connected to the outer side of the upper end of the center tube (3). The lower end of the center tube (3) is embedded in the inner side of the outer tube (10). A shearing nail (8) is provided between the center tube (3) and the outer tube (10) for limiting the axial position of the outer tube (10) on the center tube (3). Positioning steps are provided on the outer side of the lower end of the center tube (3) and the inner side of the middle section of the outer tube (10). When the shearing nail (8) is not interrupted, the positioning step on the center tube (3) contacts the positioning step on the outer tube (10). The positioning step prevents the outer tube (10) from sliding downward relative to the center tube (3). The inner side of the lower end of the outer tube (10) is threadedly connected to the outer side of the upper end of the lower joint (13).
3. A millable packer according to claim 2, characterized in that: The positioning step on the outer side of the lower end of the central tube (3) is provided by a nut (11) threadedly connected to the lower end of the central tube (3), and the positioning step is the upper end surface of the nut (11).
4. A millable packer according to claim 1, characterized in that: O-rings (6) are provided between the pressing cap (7) and the central tube (3) and between the pressing cap (7) and the outer tube (10).
5. A millable packer according to claim 4, characterized in that: A guide key (9) is also provided between the central tube (3) and the outer tube (10).
6. A millable packer according to any one of claims 1 to 5, characterized in that: The composite material is a fiber-reinforced epoxy resin composite material.
7. A millable packer according to claim 6, characterized in that: The fiber-reinforced epoxy resin composite material is a composite material added with nano-metal.
8. A millable packer according to any one of claims 1 to 5, characterized in that: Both ends of each rubber cylinder (4) are cone-shaped structures with an end diameter smaller than a middle diameter.