A packer for oil production with an expanded seal

Abstract

The application discloses a petroleum exploitation packer with an expansion type sealing structure and belongs to the field of oilfield downhole tools. The packer comprises a central pipe, upper and lower joints respectively arranged at two ends of the central pipe, a sealing assembly and a setting assembly sequentially sleeved between the two joints, and a righting assembly and a reversing assembly cooperatively connected. The sealing assembly comprises an installation pipe sleeved on the central pipe and a rubber sleeve sleeved on the outside of the installation pipe. First and second sliding rods alternately distributed and linked are slidably arranged on the installation pipe. First and second push blocks are respectively hinged on the two sliding rods. When the two sliding rods move towards the setting assembly, the first and second push blocks are alternately inserted and spliced into a sealing ring with an outer diameter greater than the inner diameter of the rubber sleeve. The installation pipe provides a stable installation base for each component. The linkage of the sliding rods ensures the coordinated and synchronous movement of the push blocks. The sealing ring is expanded by extruding the rubber sleeve to tightly adhere to the well wall to realize sealing and effectively prevent the channeling of formation fluid. The sealing reliability and response efficiency are improved by adjusting the curvature of the push blocks and the length of the push rods to realize rapid sealing under short distance movement.

Description

Technical Field

[0001] This invention belongs to the field of oilfield downhole tools, and in particular relates to an oil extraction packer with an expansion sealing structure. Background Technology

[0002] In the field of oil extraction, packers, as key downhole tools, are mainly used to separate oil, gas, and water layers at different pressures within the casing, preventing formation fluid cross-flow and ensuring the smooth implementation of operations such as pressure control, stratified extraction, and acid fracturing during the extraction process. As oil and gas resource exploration and development gradually extends to deep wells, ultra-deep wells, complex lithological formations, and secondary development of old oilfields, higher requirements are placed on the sealing reliability, setting stability, structural adaptability, and reusability of packers.

[0003] Currently, common oilfield packers on the market mainly include compression packers, expansion packers, and self-sealing packers. Compression packers apply axial pressure to the tubing string to compress the rubber sleeve, causing it to expand radially and achieve a seal. However, the compression amount of this type of packer depends on the efficiency of axial force transmission. In the high-temperature and high-pressure environment of deep wells, uneven compression can easily lead to seal failure. Furthermore, the axial force transmission process is easily affected by tubing deformation, resulting in unstable sealing. Self-sealing packers rely on formation pressure to push the rubber sleeve to expand and seal, but their sealing effect is significantly affected by formation pressure fluctuations, limiting their applicability and making them unsuitable for complex formation extraction needs.

[0004] Existing expandable packers mostly rely on a single expansion mechanism to drive the deformation of the rubber sleeve. Common expansion mechanisms, such as piston-type and bladder-type, have the following shortcomings: First, piston-type expansion mechanisms rely on hydraulic drive, and the seals are susceptible to wear from downhole impurities, leading to hydraulic leakage. Furthermore, the expansion stroke is limited, resulting in insufficient expansion of the rubber sleeve, making it difficult to adapt to irregular casing inner diameters. Second, while bladder-type expansion mechanisms can achieve a larger expansion range, the bladder material is prone to aging and cracking under high temperature and corrosive environments, resulting in a short service life. Additionally, the sealing and setting components of existing packers are mostly independently driven structures, with asynchronous operation. This can lead to rubber sleeve wear due to "sealing before setting" or delayed sealing due to "setting before sealing," affecting operational efficiency and safety.

[0005] Therefore, we need to design an oil extraction packer with an expandable sealing structure to solve these problems. Summary of the Invention

[0006] The problem to be solved by the present invention is to provide an oil extraction packer with an expansion sealing structure.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0008] An oil extraction packer with an expansion-type sealing structure includes a central tube, an upper connector at one end and a lower connector at the other end. A sealing assembly, a setting assembly, a centralizing assembly, and a reversing assembly are sequentially arranged on the central tube between the upper and lower connectors. The sealing assembly and the setting assembly are fitted onto the central tube. The centralizing assembly is connected to the lower connector. The sealing assembly includes a rubber sleeve and an installation tube. The installation tube is fitted onto the central tube, and the rubber sleeve is fitted onto the outside of the installation tube. A plurality of first sliding rods and a plurality of second sliding rods are slidably arranged on the installation tube. The plurality of first sliding rods and the plurality of second sliding rods are alternately distributed and interconnected. A first push block is hinged to each first sliding rod, and a second push block is hinged to each second sliding rod. When the plurality of first sliding rods and the plurality of second sliding rods move toward the setting assembly, the plurality of first push blocks and the plurality of second push blocks alternately interlock to form a sealing ring, and the outer diameter of the sealing ring is larger than the inner diameter of the rubber sleeve.

[0009] Preferably, the outer wall of the mounting tube is provided with a plurality of first sliding grooves and a plurality of second sliding grooves, the plurality of first sliding grooves and the plurality of second sliding grooves are alternately distributed, and a support rod is fixedly installed in the first sliding groove and the second sliding groove. The first sliding rod is located in the first sliding groove, the second sliding rod is located in the second sliding groove, the depth of the first sliding groove is greater than the depth of the second sliding groove, and one end of the plurality of first sliding rods is connected by a first connecting ring, and one end of the plurality of second sliding rods is connected by a second connecting ring, and the second connecting ring is sleeved on the outside of the plurality of first sliding rods.

[0010] This design, with its alternating grooves, accurately guides the sliding direction of the slide rod, preventing it from shifting or jamming during movement. The support rod provides support and limits the slide rod, ensuring stable sliding within the groove. The first groove is deeper than the second groove, and combined with the structure of the second connecting ring fitted around the outside of the first slide rod, this design achieves a reasonable spatial arrangement of the first and second slide rods, preventing them from colliding during sliding and ensuring smooth movement of the slide rod. This, in turn, ensures that the push block can be smoothly assembled to form a sealing ring.

[0011] Preferably, a limiting rod is fixedly provided on the first connecting ring, and a stop is fixedly provided on the free end of the limiting rod after passing through the first connecting ring. The limiting rod is slidably engaged with the second connecting ring, and a sealing spring is fitted on the limiting rod between the first connecting ring and the second connecting ring.

[0012] This design guides and limits the relative movement of the first and second connecting rings via the limiting rod, preventing lateral displacement during movement and ensuring the accuracy of the slide rod's movement. The stop block prevents the second connecting ring from detaching from the limiting rod, ensuring structural integrity. The sealing spring provides elastic support for the first and second connecting rings. When the slide rod is subjected to external force, the spring acts as a buffer, preventing damage to components due to rigid collisions. Furthermore, after the external force is removed, the spring pushes the connecting ring and slide rod back to their original positions, facilitating the reuse of the packer.

[0013] Preferably, a first push rod is hinged to the other end of each first slide rod, and there are at least two first push rods on the same first slide rod that are parallel to each other. A first push block is hinged to the free end of the first push rod. A second push rod is hinged to the other end of each second slide rod, and there are at least two second push rods on the same second slide rod that are parallel to each other. A second push block is hinged to the free end of the second push rod. When the first slide rod and the second slide rod slide to near their limit positions, the first push rod and the second push rod will be blocked by the support rod and rotate under the obstruction of the support rod.

[0014] This configuration, using multiple parallel push rods, provides more stable support and thrust for the push block, ensuring its smooth movement and preventing tilting that could affect the sealing ring's assembly quality. The push rods are hinged to the slide rods, allowing for flexible rotation. When the slide rods reach their limit positions, the support rods' blocking and guiding action ensures the push rods accurately drive the push blocks to rotate, guaranteeing precise assembly between the push blocks and forming a complete and well-sealed sealing ring, further enhancing the sealing effect.

[0015] Preferably, the sealing assembly includes a conical sleeve, a slip seat, and a plurality of slip teeth. The conical sleeve and the slip seat are both fitted onto the central tube. The slip seat has a plurality of slip grooves, which are evenly distributed around the central tube. One end of each slip tooth is inserted into a slip groove and is slidably connected to the slip groove. The other end of each slip tooth is located between the slip seat and the conical sleeve and matches the conical sleeve. When the conical sleeve moves closer to the slip seat, it will push the slip tooth to move radially along the central tube.

[0016] This configuration, with its evenly distributed slip grooves, ensures that the slip teeth are evenly distributed around the central tube, guaranteeing uniform force exerted by the slip teeth on the inner wall of the casing. This prevents excessive localized stress from damaging the casing or causing unstable sealing. The sliding connection between the slip teeth and the slip grooves, along with the matching design with the conical sleeve, allows the axial movement of the conical sleeve to be smoothly converted into the radial movement of the slip teeth. This enables the slip teeth to grip the inner wall of the casing, firmly sealing the packer inside the casing and preventing it from moving up and down during operation, thus ensuring the stability of the sealing operation.

[0017] Preferably, a conical cap is also fitted onto the central tube. The conical cap is located between the conical sleeve and the mounting tube and is connected to the central tube by a shear pin. One end of the conical cap is fixedly connected to the conical sleeve, and a support sleeve is fixedly provided at the other end. The free end of the support sleeve is in contact with the end of the mounting tube.

[0018] This configuration, using a shear pin connection, secures the cone cap to the central tube before the packer reaches the setting pressure, ensuring the relative position of the cone cap remains stable. When the set setting pressure is reached, the shear pin is cut, allowing the cone cap to move the cone sleeve towards the slip seat, achieving the setting action. The shear pin configuration allows for precise control of the setting timing, ensuring the reliability of the setting process. The support sleeve provides support and positioning between the mounting tube and the cone cap, ensuring a fixed distance between the mounting tube and the setting assembly. This prevents component misalignment from affecting the coordinated operation of the sealing and setting assemblies. Simultaneously, the support sleeve can transmit some of the force from the mounting tube, protecting the cone cap and cone sleeve from damage caused by excessive pressure.

[0019] Preferably, a slip spring is also provided in the slip groove, one end of the slip spring is fixedly connected to the slip groove, and the other end is in contact with the slip tooth, and a limit block is also fixedly provided on the side wall of the slip tooth on both sides of the slip spring.

[0020] With this configuration, the slip spring provides continuous elastic pressure to the slip teeth. After the cone sleeve pushes the slip teeth to move radially and bite the inner wall of the sleeve, the spring can further press the slip teeth together, increasing the friction between the slip teeth and the inner wall of the sleeve and improving the sealing stability. When the packer needs to be unsealed, the spring can push the slip teeth to reset, making it easy for the slip teeth to retract into the slip groove and achieve smooth unsealing of the packer. The limiting block can restrict the sliding range of the slip teeth in the slip groove, preventing the slip teeth from falling out of the slip groove or sliding excessively, ensuring that the slip teeth always move within the effective working range and guaranteeing the normal function of the sealing assembly.

[0021] Preferably, the straightening component includes a straightening body fitted on the central tube. The outer wall of the straightening body is provided with a plurality of straightening grooves. The plurality of straightening grooves are evenly distributed on the straightening body around the central tube. Each straightening groove is provided with a straightening spring and a straightening block. When the straightening spring is in the natural state, the straightening block will extend out from the straightening groove.

[0022] This configuration, with its evenly distributed straightening grooves and blocks, allows the straightening assembly to apply a straightening force uniformly around the central tube, ensuring that the central tube remains centered within the casing. This prevents the central tube from colliding and rubbing against the inner wall of the casing due to eccentricity, protecting both the central tube and the casing. It also provides good centering conditions for the normal operation of other components. The straightening spring provides elastic support for the straightening block. When the straightening block is subjected to pressure from the inner wall of the casing, the spring can be compressed, allowing the straightening block to adapt to casings of different inner diameters, improving the versatility of the straightening assembly. Furthermore, the elastic force of the spring ensures that the straightening block remains in contact with the inner wall of the casing, guaranteeing the continuity and stability of the straightening effect.

[0023] Preferably, the reversing assembly includes a reversing sleeve and a reversing column. The reversing sleeve is coaxially disposed on the outside of the lower connector. A limiting groove is provided on the reversing sleeve, and the extending direction of the limiting groove is the same as that of the central tube axis. One end of the reversing sleeve is fixedly connected to the straightening body, and the other end is provided with a guide groove. The guide groove is connected to the end of the limiting groove near the straightening body. The reversing column is fixed on the lower connector. When the reversing sleeve moves relative to the lower connector, the reversing column will slide in the guide groove or the limiting groove.

[0024] This configuration, with the reversing sleeve fixedly connected to the centralizing body, allows the centralizing body to move together with the reversing sleeve, thus adjusting the position of the centralizing body. The limiting groove limits the movement of the reversing column, ensuring that the reversing sleeve moves within a set range and preventing damage to components due to excessive movement. The connection design between the guide groove and the limiting groove guides the reversing column smoothly from the guide groove into the limiting groove or out of the limiting groove when the reversing sleeve moves, realizing the reversing function. Through the action of the reversing component, the working state of the packer can be adjusted, such as realizing the setting, unsealing, or other function conversion of the packer, improving the operational flexibility and applicability of the packer.

[0025] The advantages and positive effects of this invention are:

[0026] This invention utilizes an installation pipe to provide a stable mounting base for the rubber sleeve and sliding rod, ensuring the fixed position of each component; the alternating and linked distribution of the sliding rods ensures the coordination and synchronization of the push block movement; the outer diameter of the sealing ring formed by the first and second push blocks is larger than the inner diameter of the rubber sleeve. During sealing, the sealing ring can compress the inner wall of the rubber sleeve, causing the rubber sleeve to expand outward and fit tightly against the well wall for sealing, improving the sealing effect, effectively preventing formation fluid leakage, and improving the sealing reliability of the packer; furthermore, by adjusting the curvature of the first and second push blocks and the length of the first and second push rods, sealing can be achieved with a shorter movement distance, resulting in fast response and good sealing effect. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0029] Figure 2 This is a schematic cross-sectional view of the internal structure of the present invention;

[0030] Figure 3 This is a schematic diagram showing the positions of the first and second push blocks in the unsealed state of the present invention;

[0031] Figure 4 yes Figure 3 A schematic diagram of the internal structure longitudinal section;

[0032] Figure 5 This is a schematic diagram showing the positions of the first push block and the second push block in the sealing state of the present invention;

[0033] Figure 6 yes Figure 5 A longitudinal section diagram of the internal structure;

[0034] Figure 7 This is a schematic diagram showing the relative distribution positions of the first pusher block and the second pusher block of the present invention when they are not seated.

[0035] Figure 8 yes Figure 5 A top-down view diagram;

[0036] Figure 9 This is a schematic diagram of the installation tube and the first and second sliding grooves of the present invention.

[0037] The annotations in the attached figures are explained as follows:

[0038] 1. Upper connector; 2. Sealing assembly; 201. Glue sleeve; 202. Mounting tube; 203. First slide groove; 204. Second slide groove; 205. First connecting ring; 206. Second slide rod; 207. First slide rod; 208. Second connecting ring; 209. Sealing ring; 210. First push block; 211. Second push block; 212. First push rod; 213. Second push rod; 214. Limiting rod; 215. Stop block 216. Sealing spring; 217. Support rod; 3. Center tube; 4. Cone cap; 5. Cone sleeve; 6. Shear pin; 7. Support sleeve; 8. Centralizing body; 9. Vase tooth; 10. Vase compression spring; 11. Centralizing block; 12. Vase seat; 13. Reversing sleeve; 14. Lower connector; 15. Guide groove; 16. Reversing column; 17. Limiting groove; 18. Vase groove; 19. Limiting block; 20. Centralizing groove; 21. Centralizing spring. Detailed Implementation

[0039] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0040] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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 or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0041] The present invention will be further described below with reference to the accompanying drawings:

[0042] Example 1: As Figures 1-9As shown, an oil extraction packer with an expansion-type sealing structure includes a central tube 3. An upper connector 1 is located at one end of the central tube 3, and a lower connector 14 is located at the other end. A sealing assembly 2, a setting assembly, a centralizing assembly, and a reversing assembly are sequentially arranged on the central tube 3 between the upper connector 1 and the lower connector 14. The sealing assembly 2 and the setting assembly are fitted onto the central tube 3, and the centralizing assembly is connected to the lower connector 14. The central tube 3 serves as the core load-bearing structure of the entire packer. The upper connector 1 connects to the upper extraction tubing, and the lower connector 14 connects to the lower tubing or tools. The sequentially arranged sealing assembly 2, setting assembly, centralizing assembly, and reversing assembly form a complete functional chain from sealing and isolation to positioning and centralization. Among them, the sealing component 2 is responsible for achieving fluid isolation between formations, the setting component provides stable support for the sealing component 2 and fixes the packer inside the casing, the straightening component ensures that the packer is centered inside the casing to ensure the normal operation of each component, and the reversing component controls the setting and unsealing process through structural movement conversion. Each component uses the central tube 3 as the installation reference and achieves functional linkage through the cooperation of adjacent components.

[0043] The sealing assembly 2 includes a rubber sleeve 201 and an installation tube 202. The installation tube 202 is sleeved on the central tube 3, and the rubber sleeve 201 is sleeved on the outside of the installation tube 202. A plurality of first slide rods 207 and a plurality of second slide rods 206 are slidably arranged on the installation tube 202. The plurality of first slide rods 207 and the plurality of second slide rods 206 are alternately distributed and linked to each other. A first push block 210 is hinged to each first slide rod 207, and a second push block 211 is hinged to each second slide rod 206. When the plurality of first slide rods 207 and the plurality of second slide rods 206 move toward the sealing assembly, the plurality of first push blocks 210 and the plurality of second push blocks 211 will alternately interlock and assemble into a sealing ring 209, and the outer diameter of the sealing ring 209 is larger than the inner diameter of the rubber sleeve 201. The mounting tube 202 achieves axial positioning through the central tube 3. The sealing performance of the rubber sleeve 201 depends on the support and expansion of the internal structure. The alternating distribution of the first slide rod 207 and the second slide rod 206 ensures that there is no gap when the push blocks are assembled, and the linkage design of the two keeps the movement synchronized. When the slide rod moves towards the sealing assembly, it drives the hinged first push block 210 and second push block 211 to move synchronously, forming a complete sealing ring 209 through alternating insertion. Since the outer diameter of the sealing ring 209 is larger than the inner diameter of the rubber sleeve 201, it can generate a radial expansion force on the rubber sleeve 201, forcing the rubber sleeve 201 to expand outward and fit against the inner wall of the sleeve, thereby achieving the sealing function. The movement of the slide rod directly drives the formation of the sealing ring 209, thereby triggering the sealing action of the rubber sleeve 201.

[0044] The outer wall of the mounting tube 202 is provided with several first sliding grooves 203 and several second sliding grooves 204, which are alternately distributed. Support rods 217 are fixedly installed within the first and second sliding grooves 203 and 204. First sliding rods 207 are located within the first sliding grooves 203, and second sliding rods 206 are located within the second sliding grooves 204. The depth of the first sliding grooves 203 is greater than the depth of the second sliding grooves 204. One end of each of the first sliding rods 207 is connected by a first connecting ring 205, and one end of each of the second sliding rods 206 is connected by a second connecting ring 208, with the second connecting ring 208 fitted over the outside of each of the first sliding rods 207. The alternating distribution of the first and second sliding grooves 203 corresponds to the arrangement of the sliding rods, providing precise sliding guidance for the sliding rods. The support rods 217, fixed within the grooves, not only support the sliding rods but also provide a fulcrum for the subsequent rotation of the push rod. The depth of the first groove 203 is greater than the depth of the second groove 204. Combined with the structure where the second connecting ring 208 fits around the outside of the first slide rod 207, the first slide rod 207 and the second slide rod 206 are arranged in layers in space, preventing interference during movement. The first connecting ring 205 connects all the first slide rods 207 into a single unit, and the second connecting ring 208 connects all the second slide rods 206 into a single unit, ensuring synchronous movement of the same group of slide rods and achieving coordinated assembly of the push blocks. The linkage effect of the connecting rings ensures the consistency of the slide rod movement, providing a foundation for the stable formation of the sealing ring 209.

[0045] A limiting rod 214 is fixedly installed on the first connecting ring 205. The free end of the limiting rod 214 passes through the first connecting ring 205 and is fixedly fitted with a stop 215. The limiting rod 214 is slidably engaged with the second connecting ring 208. A sealing spring 216 is fitted onto the limiting rod 214 between the first connecting ring 205 and the second connecting ring 208. The elastic force of the sealing spring 216 is much greater than the elastic force of the rubber sleeve 201. One end of the limiting rod 214 is fixed to the first connecting ring 205, and the other end passes through the second connecting ring 208 and is restricted in its sliding stroke by the stop 215, thus limiting the relative movement of the two sets of sliding rods. The sliding engagement between the limiting rod 214 and the second connecting ring 208 ensures that the second connecting ring 208 can move axially along the limiting rod 214. The sealing spring 216, which is fitted on the limiting rod 214, is located between the first connecting ring 205 and the second connecting ring 208. When the two sets of sliding rods move relative to each other, the spring is compressed or stretched, and the elastic force of the spring is used to reset the connecting ring, thereby driving the sliding rod to reset, providing conditions for the repeated use of the packer. The engagement between the limiting rod 214 and the spring realizes the controllability of the sliding rod movement and the reset function.

[0046] A first push rod 212 is hinged to the other end of each first slide rod 207. There are at least two first push rods 212 on the same first slide rod 207, and they are parallel to each other. A first push block 210 is hinged to the free end of the first push rod 212. A second push rod 213 is hinged to the other end of each second slide rod 206. There are at least two second push rods 213 on the same second slide rod 206, and they are parallel to each other. A second push block 211 is hinged to the free end of the second push rod 213. When the first slide rod 207 and the second slide rod 206 slide to near their limit positions, the first push rod 212 and the second push rod 213 will be blocked by the support rod 217 and will rotate under the blockage of the support rod 217. The first push rod 212 is hinged to the first slide rod 207, and the second push rod 213 is hinged to the second slide rod 206, so that the push rod can move with the slide rod and rotate relative to the slide rod. The parallel push rods on the same slide rod provide balanced support for the push block, ensuring that the push block is under stable force. When the slide bar slides to its limit position, the push rod contacts the support rod 217 in the groove. The support rod 217 blocks the push rod, causing the push rod to rotate around the hinge point, which in turn pushes the push block to move radially outward, realizing the interlocking and splicing of the push block. The blocking effect of the support rod 217 converts the axial movement of the slide bar into the rotational movement of the push rod, ultimately driving the push block to form the sealing ring 209, completing the conversion and transmission of motion.

[0047] The sealing assembly includes a conical sleeve 5, a slip seat 12, and several slip teeth 9. Both the conical sleeve 5 and the slip seat 12 are fitted onto the central tube 3. The slip seat 12 has several slip grooves 18 evenly distributed around the central tube 3. One end of each slip tooth 9 is inserted into a slip groove 18 and slidably connected to it. The other end of each slip tooth 9 is located between the slip seat 12 and the conical sleeve 5 and matches the conical sleeve 5. When the conical sleeve 5 moves closer to the slip seat 12, it pushes the slip teeth 9 to move radially along the central tube 3. Both the conical sleeve 5 and the slip seat 12 slide axially guided by the central tube 3. The slip grooves 18 are evenly distributed around the central tube 3, resulting in a uniformly circumferential arrangement of the slip teeth 9. One end of the slip tooth 9 is slidably connected to the slip groove 18, restricting its movement to only radial direction. The other end engages with the conical surface of the conical sleeve 5. When the conical sleeve 5 moves axially toward the slip seat 12, the conical surface generates a radial component force, pushing the slip tooth 9 to slide outward along the slip groove 18 until the slip tooth 9 bites into the inner wall of the sleeve, thus achieving the sealing and fixing of the packer. The axial movement of the conical sleeve 5 is converted into the radial movement of the slip tooth 9 through the conical surface engagement, completing the sealing action.

[0048] A conical cap 4 is fitted onto the central tube 3. The conical cap 4 is located between the conical sleeve 5 and the mounting tube 202, and is connected to the central tube 3 via a shear pin 6. One end of the conical cap 4 is fixedly connected to the conical sleeve 5, and the other end is fixedly fitted with a support sleeve 7. The free end of the support sleeve 7 fits against the end of the mounting tube 202. The conical cap 4 is fixed to the central tube 3 via the shear pin 6, keeping the conical sleeve 5 stationary until the set pressure is reached. The fixed connection between the conical cap 4 and the conical sleeve 5 ensures that the two move synchronously. The support sleeve 7 connects the conical cap 4 and the mounting tube 202, transmitting the axial force of the conical cap 4 to the mounting tube 202. When the pressure inside the central tube 3 reaches the shearing value of the shear pin 6, the shear pin 6 breaks, and the cone cap 4 drives the cone sleeve 5 to move towards the slip seat 12. At the same time, the support sleeve 7 pushes the installation tube 202 towards the sealing assembly, which in turn drives the slide rod in the sealing assembly 2 to move, realizing the linkage action between the sealing assembly and the sealing assembly 2. The shearing of the shear pin 6 controls the start timing of the sealing and sealing actions, while the support sleeve 7 realizes the transmission of force, enabling the two sets of components to work together.

[0049] A slip spring 10 is also provided inside the slip groove 18. One end of the slip spring 10 is fixedly connected to the slip groove 18, and the other end is in contact with the slip tooth 9. Limiting blocks 19 are also fixedly provided on the side walls of the slip tooth 9 on both sides of the slip spring 10. When the slip spring 10 is in a compressed state, it provides radial thrust to the slip tooth 9, assisting the slip tooth 9 in biting the inner wall of the sleeve and enhancing the stability of the sealing. When the packer needs to be unsealed, the cone sleeve 5 moves in the opposite direction, and the slip spring 10 pushes the slip tooth 9 to slide inward along the slip groove 18 to reset. The limiting blocks 19 are fixed on the side wall of the slip tooth 9 and cooperate with the inner wall of the slip groove 18 to limit the sliding stroke of the slip tooth 9, prevent the slip tooth 9 from coming out of the slip groove 18 or sliding excessively, and ensure that the slip tooth 9 is always within the effective working range. The slip spring 10 provides auxiliary support and reset of the slip tooth 9, while the limiting blocks 19 ensure the safety and reliability of the movement of the slip tooth 9.

[0050] The straightening assembly includes a straightening body 8 fitted onto the central tube 3. The outer wall of the straightening body 8 has several straightening grooves 20 evenly distributed around the central tube 3. Each straightening groove 20 contains a straightening spring 21 and a straightening block 11. When the straightening spring 21 is in its natural state, the straightening block 11 extends out of the straightening groove 20. The straightening body 8 is fitted onto the central tube 3 and lowered into the sleeve along with the central tube 3. The straightening grooves 20 are evenly distributed around the central tube 3, resulting in a symmetrical arrangement of the straightening blocks 11. In its natural state, the straightening spring 21 pushes the straightening block 11 out of the straightening groove 20. When the straightening body 8 enters the sleeve, the straightening block 11 contacts the inner wall of the sleeve and compresses the straightening spring 21. The reaction force of the spring makes the straightening block 11 stick tightly to the inner wall of the sleeve. Through the joint action of the evenly distributed straightening blocks 11, the central tube 3 and each component are centered and positioned, avoiding the packer from being eccentric, which would cause the sealing component 2 to not seal properly or the seated sealing component to be subjected to uneven force. The elastic effect of the straightening spring 21 allows the straightening block 11 to adapt to sleeves with different inner diameters, ensuring the versatility of the straightening effect.

[0051] The reversing assembly includes a reversing sleeve 13 and a reversing column 16. The reversing sleeve 13 is coaxially disposed on the outside of the lower connector 14. A limiting groove 17 is provided on the reversing sleeve 13, and the extending direction of the limiting groove 17 is the same as the axis of the central tube 3. One end of the reversing sleeve 13 is fixedly connected to the straightener 8, and the other end has a guide groove 15. The guide groove 15 is connected to the end of the limiting groove 17 near the straightener 8. The reversing column 16 is fixed on the lower connector 14. When the reversing sleeve 13 moves relative to the lower connector 14, the reversing column 16 will slide within the guide groove 15 or the limiting groove 17. The reversing sleeve 13 is fixedly connected to the straightener 8 and moves with the straightener 8. The reversing column 16 is fixed on the lower connector 14 and remains stationary. The guide groove 15 and the limiting groove 17 are connected to form the movement trajectory of the reversing column 16. During packer insertion, the reversing sleeve 13 moves relative to the lower connector 14, and the reversing column 16 slides along the guide groove 15, guiding the reversing sleeve 13 to move in a specific direction. During setting, the reversing column 16 moves to its limit position along the limiting groove 17 and then rotates the tubing. This rotation drives the lower connector 14 to rotate, causing the reversing column 16 to move from the limiting groove 17 into the guide groove 15, and then the tubing moves downwards. The sliding transition of the reversing column 16 within different grooves provides structural guidance for the setting and unsetting processes.

[0052] The working process of this embodiment is as follows: First, the packer is connected to the mining tubing via the upper connector 1 and the lower connector 14, and is lowered into the casing along with the tubing. At this time, the cone cap 4 is fixed to the central tube 3 by the shear pin 6, so that the cone sleeve 5, the support sleeve 7, and the installation tube 202 remain in their initial positions; in the sealing assembly 2, the first connecting ring 205 and the second connecting ring 208 are in a separated state under the action of the sealing spring 216, the first sliding rod 207 and the second sliding rod 206 are located in the initial position close to the upper connector 1, the first push block 210 and the second push block 211 are in an unassembled state, and the rubber sleeve 201 is also in an unexpanded state; in the setting assembly, The slip tooth 9 retracts into the slip groove 18 under the action of the slip compression spring 10; in the straightening assembly, the straightening block 11 is squeezed by the inner wall of the sleeve, compressing the straightening spring 21 and partially retracting into the straightening groove 20. The reaction force of the straightening spring 21 keeps the straightening block 11 close to the inner wall of the sleeve, ensuring that the central tube 3 and each component are centered in the sleeve; in the reversing assembly, the reversing sleeve 13 moves down with the tube column, and the reversing column 16 fixed on the lower connector 14 is located in the limiting groove 17 on the reversing sleeve 13 at this time.

[0053] After the packer is lowered to the area to be sealed, the tubing string is lifted, and the upper connector 1, the central tube 3, and the lower connector 14 are pulled upwards by the tubing string. When the reversing column 16 moves to its limit position, the tubing string is rotated, and the lower connector 14 is rotated by the tubing string, so that the reversing column 16 enters the guide groove 15 from the limiting groove 17. Then the tubing string is moved downwards, so that the upper connector 1, the central tube 3, and the lower connector 14 move downwards as a whole. During the up and down movement of the upper connector 1, the central tube 3, and the lower connector 14, the central block 11 is in close contact with the well wall under the action of the centralizing spring 21, so the central block 11 will remain relatively stationary with the slip seat 12 and the reversing sleeve 13 in the current position.

[0054] When the lower connector 14 moves to contact the cone sleeve 5 and the slip tooth 9, its conical surface contacts the inclined surface of the slip tooth 9 and generates a radial force, pushing the slip tooth 9 to slide outward along the slip groove 18. As the cone sleeve 5 moves, the slip tooth 9 gradually extends out of the slip groove 18 and bites the inner wall of the sleeve, achieving the sealing and fixing of the packer. During this process, the slip spring 10 is compressed, storing elastic potential energy. The central tube 3 continues to move downward, and the shear pin 6 connecting the cone sleeve 5 and the central tube 3 is cut off by shearing force. At this point, the cone sleeve 5 stops moving downwards, while the upper connector 1 pushes the first connecting ring 205 downwards. The first connecting ring 205 then pushes the second connecting ring 208 downwards via the sealing spring 216. The first slide rod 207 and the second slide rod 206 also move along the first slide groove 203 and the second slide groove 204 on the mounting tube 202. When the second push rod 213 on the second slide rod 206 contacts the support rod 217, it pushes the mounting tube 202 towards the support sleeve 7. The support sleeve 7 is connected to the cone cap 4. At this time, the slip teeth 9 are restricted by the well wall and cannot expand outward, so the cone sleeve 5 cannot move downward, and the cone cap 4 will stop moving downward. Therefore, when the installation pipe 202 contacts the support sleeve 7, the installation pipe 202 stops moving downward. Thus, when the second slide rod 206 continues to move along the second slide groove 204, the support rod 217 will block the second push rod 213, causing the second push rod 213 to rotate and push the second push block 211 outward. When the second push block 211 is pushed to its extreme... After the position is limited, as the first connecting ring 205 continues to move downward, the sealing spring 216 will be compressed, the first push rod 212 will contact and rotate with the support rod 217 in the first slide groove 203, inserting the first push block 210 into the gap between two adjacent second push blocks 211, so that the second push block 211 and the first push block 210 form a sealing ring 209, and the sealing ring 209 will squeeze the rubber cylinder 201 outward, so that the rubber cylinder 201 fits tightly with the well wall, completing the setting of the packer in the well.

[0055] After the packer is seated and sealed, the cone sleeve 5 will continuously apply radial thrust to the slip teeth 9 to ensure that the slip teeth 9 stably bite the inner wall of the casing; the sealing ring 209 will always maintain an expansion force on the rubber sleeve 201, so that the rubber sleeve 201 fits tightly with the inner wall of the casing and maintains the sealing effect.

[0056] The packer is pulled upward by the tubing column. The tubing column drives the central tube 3 and the upper connector 1 to move upward. At this time, the slip tooth 9 slides inward along the slip groove 18 under the elastic potential energy of the slip compression spring 10 and retracts into the slip groove 18.

[0057] During unsealing, the packer is pulled upwards through the tubing column. The upper connector 1, the central tube 3, and the lower connector 14 will move upwards. After the upper connector 1 moves upwards, the first connecting ring 205 loses pressure. At this time, the first connecting ring 205 will also start to move upwards. When the sealing spring 216 extends, the second connecting ring 208 remains in its current position. When the limiting rod 214 moves to the stop 215 and contacts the second connecting ring 208, the second connecting ring 208 will move upwards with the first connecting ring 205 under the action of the limiting rod 214. During the upward movement, since the first push rod 212 and the second push rod 213 lose the support of the support rod 217, they are also pushed inwards to reset as the rubber sleeve 201 recovers, causing the sealing ring 209 to be disassembled and the seal to be released.

[0058] After the cone sleeve 5 loses the pressure transmitted from the cone cap 4, it will no longer apply radial thrust to the slip tooth 9. The slip tooth 9 will then move into the slip groove 18 under the action of the slip compression spring 10. After the slip tooth 9 is reset, the packer is unsealed.

[0059] Subsequently, as the tubing string continues to be pulled up, the reversing column 16 will enter the limiting groove 17 along the guide groove 15, driving the packer upwards with the tubing string. During this process, the centralizing block 11 remains in close contact with the inner wall of the casing under the action of the centralizing spring 21, ensuring a smooth retrieval process and guiding the packer to be successfully retrieved from the well.

[0060] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A packer for oil production having an expanding seal, characterized in that: The utility model provides a center tube (3) is provided with upper joint (1) on one end of center tube (3), is provided with lower joint (14) on the other end, is provided with sealing assembly (2), seat seal assembly, centralizing assembly and reversing assembly in sequence on center tube (3) between upper joint (1) with lower joint (14), sealing assembly (2) and seat seal assembly are sleeved on center tube (3), centralizing assembly is connected with lower joint (14) each other, sealing assembly (2) includes rubber tube (201) and installation pipe (202), installation pipe (202) is sleeved on center tube (3), rubber tube (201) is sleeved on the outside of installation pipe (202), a plurality of first slide bar (207) and a plurality of second slide bar (206) are slidably arranged on installation pipe (202), a plurality of first slide bar (207) and a plurality of second slide bar (206) are alternately distributed and are linked with each other, first push block (210) is hinged on every first slide bar (207), second push block (211) is hinged on second slide bar (206), when a plurality of first slide bar (207) and a plurality of second slide bar (206) move towards seat seal assembly, a plurality of first push block (210) and a plurality of second push block (211) will alternately be inserted into and spliced into sealing ring (209), and the outer diameter of sealing ring (209) is greater than the inner diameter of rubber tube (201);The seat seal assembly includes a cone sleeve (5), a slip bowl (12) and a plurality of slip teeth (9), the cone sleeve (5) and the slip bowl (12) are sleeved on the center tube (3), a plurality of slip grooves (18) are formed in the slip bowl (12), a plurality of slip grooves (18) are evenly distributed around the center tube (3), one end of a plurality of slip teeth (9) is inserted into the slip groove (18) and is slidably connected with the slip groove (18), the other end of the slip tooth (9) is located between the slip bowl (12) and the cone sleeve (5) and is matched with the cone sleeve (5), when the cone sleeve (5) approaches the slip bowl (12), the slip tooth (9) is pushed to move along the radial direction of the center tube (3);A cone cap (4) is also sleeved on the center tube (3), the cone cap (4) is located between the cone sleeve (5) and the installation pipe (202) and is connected with the center tube (3) through a shear pin (6), one end of the cone cap (4) is fixedly connected with the cone sleeve (5), and the other end is fixedly provided with a support sleeve (7), and the free end of the support sleeve (7) is attached to the end of the installation pipe (202).

2. The packer with an expanding seal for oil and gas production according to claim 1, characterized in that: The outer wall of the installation pipe (202) is provided with a plurality of first sliding grooves (203) and a plurality of second sliding grooves (204), the plurality of first sliding grooves (203) and the plurality of second sliding grooves (204) are alternately distributed, the first sliding grooves (203) and the second sliding grooves (204) are fixedly provided with support rods (217) therein, the first sliding rods (207) are located in the first sliding grooves (203), the second sliding rods (206) are located in the second sliding grooves (204), the depth of the first sliding grooves (203) is greater than that of the second sliding grooves (204), and one end of the plurality of first sliding rods (207) is connected through a first connecting ring (205), one end of the plurality of second sliding rods (206) is connected through a second connecting ring (208), and the second connecting ring (208) is sleeved on the outside of the plurality of first sliding rods (207).

3. The packer of claim 2, wherein: A limiting rod (214) is fixedly arranged on the first connecting ring (205), a free end of the limiting rod (214) is fixedly provided with a stop block (215) after penetrating through the first connecting ring (205), and the limiting rod (214) is in sliding fit with the second connecting ring (208), and a sealing spring (216) is sleeved on the limiting rod (214) between the first connecting ring (205) and the second connecting ring (208).

4. The packer of claim 2, wherein: A first push rod (212) is hingedly connected to the other end of each first sliding rod (207), the first push rods (212) on the same first sliding rod (207) are at least two and parallel to each other, and the first push block (210) is hingedly connected to the free end of the first push rod (212); a second push rod (213) is hingedly connected to the other end of each second sliding rod (206), the second push rods (213) on the same second sliding rod (206) are at least two and parallel to each other, and the second push block (211) is hingedly connected to the free end of the second push rod (213), when the first sliding rod (207) and the second sliding rod (206) slide to the proximity of the limit position, the first push rod (212) and the second push rod (213) will be blocked by the support rod (217) and rotate under the block of the support rod (217).

5. The packer of claim 1, wherein: The slip groove (18) is further provided with a slip spring (10), one end of the slip spring (10) is fixedly connected with the slip groove (18), and the other end is attached to the slip teeth (9), and a limiting block (19) is further fixedly arranged on the side wall of the slip teeth (9) on both sides of the slip spring (10).

6. The packer of claim 1, wherein: The centralizing assembly comprises a centralizing body (8) sleeved on the central pipe (3), a plurality of centralizing grooves (20) are formed in the outer wall of the centralizing body (8), the plurality of centralizing grooves (20) are evenly distributed on the centralizing body (8) around the central pipe (3), a centralizing spring (21) and a centralizing block (11) are arranged in each centralizing groove (20), and when the centralizing spring (21) is in a natural state, the centralizing block (11) will extend out of the centralizing groove (20).

7. The packer of claim 6, wherein: The reversing assembly comprises a reversing sleeve (13) and a reversing column (16), the reversing sleeve (13) is coaxially arranged outside the lower joint (14), a limiting groove (17) is arranged on the reversing sleeve (13), the extending direction of the limiting groove (17) is the same as the axis of the central pipe (3), one end of the reversing sleeve (13) is fixedly connected with the centralizing body (8), the other end is provided with a guide groove (15), the guide groove (15) is connected with the end part of the limiting groove (17) close to the centralizing body (8), the reversing column (16) is fixed on the lower joint (14), when the reversing sleeve (13) moves relative to the lower joint (14), the reversing column (16) will slide in the guide groove (15) or the limiting groove (17).

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