A permanent hydrostatic packer

Abstract

This invention relates to the field of downhole operations and packers for oil and gas wells, and discloses a permanent hydrostatic packer, comprising a central tubing assembly and a drive assembly, an anchoring assembly, and a locking assembly connected to the central tubing assembly. The drive assembly is used to drive the anchoring assembly through downhole fluid pressure differential, causing the anchoring assembly to abut against the internal passage of the tubing to form a seal against the internal passage. The locking assembly is used to restrict the movement direction of the anchoring assembly. The purpose of this invention is to solve the problem that after the packer is driven by hydrostatic pressure, the movement direction of the anchoring component cannot be effectively restricted, resulting in unstable abutment and sealing effect against the internal passage.

Description

Technical Field

[0001] This invention relates to the field of downhole operations and packers for oil and gas wells, specifically a permanent hydrostatic packer. Background Technology

[0002] When offshore oil wells and deep wells are constructed in formations that require long-term isolation, packers are often required to reliably seal the well in the downhole environment and maintain a stable anchoring state during the isolation period, so that the sealing interface can effectively resist and seal the internal passage of the tubing for a long time.

[0003] However, some sealing structures do not adequately restrict the movement direction of the anchoring components after the action is completed, which makes the anchoring components prone to attitude displacement during or after holding the internal channel, resulting in unstable sealing interface fit. Summary of the Invention

[0004] The purpose of this invention is to solve the problem that the direction of movement of the anchoring component cannot be effectively restricted after the packer is driven by hydrostatic pressure, which leads to unstable resistance and sealing effect on the internal channel. Therefore, a permanent hydrostatic packer is proposed.

[0005] An embodiment of the present invention provides a permanent hydrostatic packer, including a central tube assembly and a drive assembly, an anchoring assembly, and a locking assembly connected to the central tube assembly. The drive assembly is used to drive the anchoring assembly through downhole fluid pressure differential, causing the anchoring assembly to abut against the internal passage of the tubing to form a blockage of the internal passage. The locking assembly is used to restrict the direction of movement of the anchoring assembly.

[0006] In one embodiment, the locking component includes: A connecting sleeve is slidably fitted onto the central tube assembly; Locking ring seat, connected to the connecting sleeve; Locking teeth are distributed on the outer wall of the central tube assembly; A locking ring is connected to the locking ring seat and forms a one-way stop engagement with the locking teeth.

[0007] In one embodiment, the drive assembly includes a dual-piston drive member and an internal hydraulic drive member disposed on the central tube assembly.

[0008] In one embodiment, the dual-piston drive component includes: The lower piston sleeve is slidably sleeved on the central tube assembly, and the lower piston sleeve and at least a portion of the outer wall of the central tube assembly form a first piston cavity; An upper piston sleeve is slidably sleeved on the central tube assembly and is connected to the connecting sleeve and abuts against the lower piston sleeve respectively. The upper piston sleeve and at least a portion of the outer wall of the central tube assembly form a second piston cavity. The first piston chamber and the second piston chamber are arranged axially along the central tube assembly. Under the action of the downhole fluid pressure difference, they are used to generate axial driving force on the lower piston sleeve and the upper piston sleeve, and transmit the axial driving force to the connecting sleeve.

[0009] In one embodiment, it further includes: The stepped portion is connected to the upper piston sleeve; A limiting block is disposed through the stepped portion, and the limiting block abuts against the central tube assembly and the lower piston sleeve respectively; An obstacle avoidance station is provided on the lower piston sleeve to accommodate the limiting block.

[0010] In one embodiment, the internal hydraulic drive component includes: A protrusion is connected to the central tube assembly, wherein the protrusion, together with the connecting sleeve, the upper piston sleeve, and the central tube assembly, forms a driving cavity; The pressure transmission hole is interconnected with the driving cavity.

[0011] In one embodiment, the anchoring assembly includes a plurality of anchoring members and a sealing member, the sealing member being located between adjacent anchoring members.

[0012] In one embodiment, the anchoring member includes: The upper vertebral body and the lower vertebral body are respectively connected to the central tube assembly by a first shear pin; The upper slip and the lower slip are respectively connected to the upper vertebral body and the lower vertebral body by a second shear pin.

[0013] In one embodiment, the sealing member includes a sealing sleeve assembly, the sealing sleeve assembly slide being fitted onto the central tube assembly and located between the upper cone and the lower cone.

[0014] In one embodiment, a pressure plate is also included, which is connected to the central tube assembly by fixing screws, and the pressure plate abuts against the outer wall of at least a portion of the upper slip.

[0015] Compared with the prior art, the technical solution of this application has the following beneficial technical effects: This invention uses a central tube assembly as the core for support and connection, enabling subsequent execution and stabilization mechanisms to maintain coordination during the packing process. The drive section utilizes the downhole medium pressure differential to provide force, allowing the anchoring component to abut against the internal tubing channel at a predetermined time and establish the contact state required for sealing. After the anchoring component completes abutment, the locking section directionally constrains its subsequent displacement, suppressing uncontrolled attitude adjustments under formation disturbances, load changes, or operating condition fluctuations. This improves the sealing reliability and engineering adaptability of the packer under long-term isolation conditions. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall connection structure of the present invention; Figure 2 This is a schematic diagram of the connection structure between the central tube assembly and part of the dual-piston drive component of the present invention; Figure 3 This is a schematic diagram of the connection structure between the dual-piston drive component and the internal hydraulic drive component of the present invention; Figure 4 This is a schematic diagram of the connection structure between the anchoring component and the locking component of the present invention; Figure 5 This is a schematic diagram of the connection structure of the anchoring component of the present invention; Figure 6 This is a schematic diagram of the connection structure between the stepped portion and the limiting block of the present invention.

[0017] In the diagram: 1. Central tube assembly; 2. Drive assembly; 21. Dual piston drive component; 211. Lower piston sleeve; 212. Upper piston sleeve; 213. Stepped section; 214. Limiting block; 215. Clearance station; 216. Lower connector; 217. Third shear pin; 218. Rupture disc; 22. Internal hydraulic drive component; 221. Protrusion; 222. Pressure transmission hole; 3. Anchoring assembly; 31. Anchoring component; 311. Upper cone; 312. Lower cone; 313. First shear pin; 314. Upper slip; 315. Lower slip; 316. Second shear pin; 32. Sealing component; 4. Locking assembly; 41. Connecting sleeve; 42. Locking ring seat; 43. Locking tooth; 44. Locking ring component; 5. Pressure plate; 6. Fixing screw. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] This application provides a permanent hydrostatic packer, including a central tube assembly 1 and a drive assembly 2, an anchoring assembly 3 and a locking assembly 4 connected to the central tube assembly 1. The drive assembly 2 is used to drive the anchoring assembly 3 through the downhole fluid pressure difference, so that the anchoring assembly 3 abuts against the internal passage of the tubing to form a blockage of the internal passage. The locking assembly 4 is used to restrict the movement direction of the anchoring assembly 3.

[0020] This permanent hydrostatic packer uses a central tube assembly 1 as its main framework. The central tube assembly 1 consists of an upper central tube, a mandrel, and a lower central tube, with the mandrel located between the upper and lower central tubes. Around the outer periphery of the central tube assembly 1, a drive assembly 2 for triggering the action, an anchoring assembly 3 for engaging with the wellbore wall, and a locking assembly 4 to ensure the packer does not retract after positioning. During the downhole process, after the packer is positioned to the target layer along with the tubing, the downhole static pressure creates a pressure difference between the sealing cavity and the external annulus, generating axial thrust. This drives the anchoring assembly 3 to establish a reliable contact with the wellbore wall and form a sealing interface. After the anchoring mechanism is in place, the locking assembly 4 blocks any subsequent reverse displacement of the anchoring components, thus preventing the contact relationship from changing with load fluctuations. This design allows the packer to maintain a more stable interface and stress posture after the initial sealing is completed, thereby improving the reliability of long-term isolation and the safety margin for repeated operations.

[0021] In some embodiments of this application, the locking component 4 includes: Connecting sleeve 41 is slidably sleeved on central tube assembly 1; Locking ring seat 42 is connected to connecting sleeve 41; Locking teeth 43 are distributed on the outer wall of the central tube assembly 1; The locking ring 44 is connected to the locking ring seat 42 and forms a one-way stop fit with the locking teeth 43. The connecting sleeve 41 is a thin-walled cylindrical structure that is coaxially slidably sleeved on the outer wall of the spindle of the central tube assembly 1. Figure 1 and Figure 4 As shown, the lower end of the connecting sleeve 41 is rigidly connected to the upper piston sleeve 212 in the drive assembly 2, thereby receiving the axial thrust generated by the drive assembly 2.

[0022] The locking ring seat 42 serves as a fixing component, providing a stable mounting base and load-bearing reference for the locking ring 44, preventing it from shifting or deforming under long-term setting pressure, thus ensuring the long-term reliability of the stop fit. The locking teeth 43 can be arranged on the mandrel of the central tube assembly 1 in a circumferentially evenly distributed or locally densely distributed manner to enhance the load-bearing capacity of the stop. The locking teeth 43 are designed with a double-sided tooth profile: one side is a gently sloping guide surface, used to guide the locking ring 44 smoothly through during the upward movement of the setting seal; the other side is a right-angle engaging surface, used to engage with the locking ring 44 under reverse load, preventing reverse movement.

[0023] During the setting process, when the axial thrust drives the connecting sleeve 41 to move upward, the inner teeth of the locking ring 44 also slide smoothly along the locking teeth 43 on the outer wall of the central tube assembly 1. After setting is completed, when a pressure difference is formed between the upper annulus and the lower annulus, this pressure difference is transmitted to the locking ring seat 42 through the sealing member and the anchoring member. At this time, the inner teeth of the locking ring 44 and the locking teeth 43 on the outer wall of the central tube assembly 1 form a right-angle engagement, and the two together prevent the locking ring seat 42 from retracting downward, thereby locking the setting force in place.

[0024] In some embodiments of this application, the drive assembly 2 includes a dual-piston drive component 21 and an internal hydraulic drive component 22 disposed on the central tube assembly 1. The dual-piston drive component 21 is the main power source for achieving setting. It generates axial thrust under the action of downhole fluid pressure differential. Figure 2 and Figure 3 As shown, compared with the traditional single-piston structure, the parallel dual-piston design can reduce the required trigger pressure under the same setting thrust demand, improving its applicability in shallow wells or low-pressure environments. Simultaneously, the parallel structure of the dual pistons disperses pressure, reducing the compressive strength of individual pistons and contributing to long-term reliability.

[0025] When the dual-piston drive component 21 malfunctions and cannot start normally to perform the setting action, the operator first seals the wellbore passage below the packer to form a closed pressure chamber. Then, the packer is set by the internal hydraulic drive component 22. High-pressure fluid is injected into the packer, causing the packer's rubber sleeve assembly to expand radially under the internal hydraulic action until it fits tightly against the inner wall of the wellbore, thus completing the packer setting operation.

[0026] In some embodiments of this application, the dual-piston drive member 21 includes: The lower piston sleeve 211 is slidably sleeved on the central tube assembly 1, and the lower piston sleeve 211 and at least a portion of the outer wall of the central tube assembly 1 form a first piston cavity. The upper piston sleeve 212 is slidably sleeved on the central tube assembly 1 and is connected to the connecting sleeve 41 and abuts against the lower piston sleeve 211 respectively. The upper piston sleeve 212 and at least a portion of the outer wall of the central tube assembly 1 form a second piston cavity. The first piston chamber and the second piston chamber are arranged axially along the central tube assembly 1. Under the action of the downhole fluid pressure difference, they are used to generate axial driving force on the lower piston sleeve 211 and the upper piston sleeve 212, and transmit the axial driving force to the connecting sleeve 41. A lower connector 216 is also provided on the lower central tube of the central tube assembly 1. In the initial state, the lower piston sleeve 211 and the lower connector 216 are fixed by a third shear pin 217. An inner protrusion is also provided on the inner wall of the lower piston sleeve 211. The inner protrusion of the lower piston sleeve 211, together with the lower central tube and the lower connector 216 of the central tube assembly 1, forms a sealed chamber. A rupture disc 218 is also provided on the lower piston sleeve 211. The rupture disc 218 is interconnected with the sealed chamber. In the unset state, the pressure in the sealed chamber is close to zero vacuum or atmospheric pressure. Figure 2 and Figure 3 As shown, the downhole fluid pressure differential can crush the ruptured disc. When the ruptured disc 218 ruptures, high-pressure fluid rushes into the sealed chamber, causing the pressure inside the chamber to rise instantly to the annular pressure value. This creates an upward hydraulic thrust on the lower end face of the lower piston sleeve 211, driving the lower piston sleeve 211 to overcome the shearing resistance of the third shear pin 217 and move upward.

[0027] The lower piston sleeve 211 is a hollow cylindrical structure that is slidably fitted coaxially onto the outer wall of the central tube assembly 1, located above the lower connector 216. The lower piston sleeve 211 and the lower central tube of the central tube assembly 1 form the first piston chamber. A sliding seal is formed between the inner wall of the lower piston sleeve 211 and the lower outer wall of the central tube assembly 1 by a sealing ring and a back ring to prevent liquid leakage along the gap.

[0028] The upper piston sleeve 212 is a hollow cylindrical structure that is slidably fitted coaxially onto the outer wall of the central tube assembly 1, located above the lower piston sleeve 211. A sliding seal is also formed between the upper piston sleeve 212 and the middle section outer wall of the central tube assembly 1 by a sealing ring and a back ring. The annular space formed by the upper piston sleeve 212 and the outer wall of the mandrel of the central tube assembly 1 constitutes the second piston chamber.

[0029] The first and second piston chambers are arranged sequentially along the axial direction of the central tube assembly 1, forming an axial superposition. Through a rational design of the piston area and pressure, the pressure of the two chambers can be superimposed in parallel, making the total axial driving force equal to the vector sum of the thrust generated by the two individual piston chambers. Under the action of the downhole fluid pressure differential, the two piston chambers simultaneously generate axial driving force. Through the abutting relationship between the lower piston sleeve 211 and the upper piston sleeve 212, the thrust is transmitted to the connection point between the upper piston sleeve 212 and the connecting sleeve 41, and then to the locking assembly 4 and the anchoring assembly 3, driving the entire setting process. The entire process realizes the parallel introduction of fluid pressure and the series superposition of mechanical thrust. This structure expands the total pressure-bearing area, and while ensuring the same setting axial thrust output, it can reduce the required hydraulic setting pressure.

[0030] In some embodiments of this application, it also includes: Stepped portion 213 is connected to upper piston sleeve 212; A limiting block 214 is disposed through the step portion 213, and the limiting block 214 abuts against the central tube assembly 1 and the lower piston sleeve 211 respectively. The clearance station 215, located on the lower piston sleeve 211, is used to accommodate the limiting block 214. The stepped portion 213 is connected to the upper piston sleeve 212, serving as an axial structural extension of the upper piston sleeve 212. The stepped portion 213 provides a mounting base for the limiting block 214 and forms an axial positioning mechanism through its cooperation with the limiting block 214.

[0031] like Figure 3 and Figure 6 As shown, the limiting block 214 is a block-shaped part with a certain thickness, which is installed through the stepped portion 213. Several limiting blocks 214 can be provided. Each limiting block 214 has two key functional surfaces in the radial direction: one surface abuts against the outer wall of the central tube assembly 1, where a first serrated portion is provided on the outer wall of the mandrel of the central tube assembly 1, and a second serrated portion is provided on the side surface of the limiting block 214 near the first serrated portion to mesh with it; the other surface abuts against the inner wall of the lower piston sleeve 211. In the initial unset state, the limiting block 214 locks the axial relative movement between the upper piston sleeve 212 and the central tube assembly 1, preventing accidental piston movement due to pressure or vibration during transportation.

[0032] The clearance station 215 is located on the inner wall of the lower piston sleeve 211 and is an axially extending long groove or recessed structure. When the lower piston sleeve 211 rises to a specific position during its upward movement, this clearance space aligns with the radial position of the limiting block 214. At this time, the limiting block 214, under its own elastic force, ejects radially outward and enters the space provided by the clearance station 215. After the limiting block 214 completely disengages from its locking relationship with the mandrel of the central tube assembly 1, the upper piston sleeve 212 gains the ability to slide freely along the axial direction and can continue to follow the lower piston sleeve 211 upward until the setting is completed.

[0033] In some embodiments of this application, the internal hydraulic drive component 22 includes: The protrusion 221 is connected to the central tube assembly 1, wherein the protrusion 221, the connecting sleeve 41, the upper piston sleeve 212 and the central tube assembly 1 together form a driving cavity; The pressure transmission hole 222 communicates with the drive cavity. In this embodiment, the protrusion 221 is an integrally formed or structural protrusion fixed to the outer wall of the mandrel of the central tube assembly 1. It is used to form a local radial height on the outer wall of the central tube, and together with the lower end face of the connecting sleeve 41, the inner circumferential surface of the upper piston sleeve 212, and the outer circumferential surface of the central tube assembly 1, it forms a closed annular drive cavity. This cavity serves as a power conversion space for the backup drive, converting hydraulic pressure into the axial driving force of the upper piston sleeve 212. The pressure transmission hole 222 is used to establish a hydraulic transmission channel, allowing high-pressure fluid injected from the ground to enter the drive cavity and provide power for the backup drive.

[0034] When the dual-piston drive component 21 fails to set properly, the wellbore passage below the packer is first sealed by conventional tools such as ball dropping and bridge plug insertion to form a closed pressure chamber; then high-pressure fluid is injected from the ground through the internal passage of the central tube. The fluid enters the sealed drive chamber through the pressure transmission hole 222. After the pressure increases, it pushes the upper piston sleeve 212 to move axially downward, causing the rubber sleeve assembly to expand radially and fit tightly against the inner wall of the wellbore, thus completing the setting.

[0035] The entire process can achieve seamless switching between main and backup drives without the need for additional complex components. While ensuring a compact structure, it significantly improves the reliability and fault tolerance of the setting and sealing system, avoids unnecessary tripping and drilling operations, and reduces operating costs and safety risks.

[0036] In some embodiments of this application, the anchoring assembly 3 includes a plurality of anchoring members 31 and sealing members 32, the sealing members 32 being located between adjacent anchoring members 31, the plurality of anchoring members 31 being evenly distributed circumferentially, and each anchoring member 31 comprising a combination of a pair of cones and slips. Figure 4 and Figure 5 As shown, when the axial driving force is transmitted to each anchoring member 31, each pair of cones converts the axial force into a radial component through the conical features of their surfaces, driving the slip to expand outward. The simultaneous action of multiple anchoring members ensures that the sealing member 32 receives uniform support from all directions, greatly improving the stability and stress balance of the sealing member.

[0037] The sealing member 32 is located between adjacent anchoring members 31. The function of the sealing member 32 is not only to complete the hydraulic sealing of the annulus, but also, after the sealing member completes radial expansion under axial compression and contacts the well wall, it is constrained by the anchoring member to a specific axial position. This ensures that under long-term annular pressure differential, both the seal and the anchoring can maintain a relatively stable state, and the whole system will not fail due to the slight displacement of a single component.

[0038] In particular, when encountering uneven well walls or asymmetrical loads caused by formation eccentricity, the dispersed distribution of multiple anchoring components allows these uneven loads to be distributed across multiple support points, significantly reducing local stress concentration compared to a single anchoring point design.

[0039] In some embodiments of this application, the anchoring member 31 includes: The upper vertebral body 311 and the lower vertebral body 312 are respectively connected to the central tube assembly 1 by the first shear pin 313; Upper slip 314 and lower slip 315 are respectively connected to upper cone 311 and lower cone 312 via second shear pins 316. Upper cone 311 and lower cone 312 are both annular parts with conical surfaces, and are respectively connected to the central tube assembly 1 via first shear pins 313. Figure 4 and Figure 5 As shown, the upper cone 311 has its conical surface facing upwards, and the lower cone 312 has its conical surface facing downwards, forming two opposing conical structures. This symmetrical design of the double cones allows the anchoring assembly 3 to simultaneously resist axial loads from both above and below after setting, and to guide the upper slip 314 and lower slip 315 to move along their conical surfaces. When a pressure difference occurs between the upper and lower annulus, regardless of the direction of the pressure difference, the corresponding slip can provide anchoring force through its corresponding cone to resist this pressure difference load, thereby preventing axial movement of the packer.

[0040] In the initial unset state, the function of the first shear pin 313 is to ensure that the vertebral body will not be prematurely displaced due to vibration during transportation and lowering or slight pressure from the ground tubing. When the axial load gradually increases to a certain threshold during the setting process, the first shear pin 313 shears off, and the vertebral body is released from the central tubing assembly 1, gaining the freedom to move axially.

[0041] The upper slip 314 and lower slip 315 mate with the conical surfaces of the upper cone 311 and lower cone 312, respectively, forming a conical sliding pair. The inner side of the slip contacts the conical surface of the cone. When the cone moves upward under axial thrust, the slip slides outward along the conical surface of the cone, gradually achieving radial expansion. The slip tooth tips are treated with high frequency hardening to form a high-hardness surface layer. During setting, the slip gradually embeds into the casing or well wall as it expands radially, forming a strong mechanical engagement and preventing the packer from slipping or dislodging.

[0042] The packer's setting action is completed sequentially according to a preset time sequence: when the axial driving force reaches the rated shearing force of the first shear pin 313, the first shear pin 313 on the lower cone 312 is sheared first, and the lower cone 312 begins to slide upward axially and push the sealing member 32 to expand radially; subsequently, the first shear pin 313 on the upper cone 311 is sheared, and as the axial load continues to increase to the rated shearing force of the second shear pin 316, the second shear pin 316 on the upper slip is sheared, and the upper slip completes complete radial expansion and forms a preliminary engagement with the well wall; finally, the second shear pin 316 on the lower slip 314 is sheared, and the lower slip 314 completes complete radial expansion and forms a firm engagement with the well wall, thus completing the entire slip setting action.

[0043] In some embodiments of this application, the sealing member 32 includes a sealing sleeve assembly. The sealing sleeve assembly slide is fitted onto the central tube assembly 1 and located between the upper cone 311 and the lower cone 312. The sealing sleeve assembly is an elastic element that engages with the upper central tube of the central tube assembly 1 through a sleeved arrangement. Figure 4 and Figure 5 As shown, the sealing sleeve assembly is located between the upper cone 311 and the lower cone 312. During the setting process, the piston system moves upward, and the upper piston sleeve 212 abuts against the lower cone 312 through the locking ring seat 42. The lower cone 312 applies axial pressure to the sleeve assembly. Under this axial pressure, the sleeve assembly undergoes axial compression. Simultaneously, utilizing the elasticity of the sleeve material, it expands outward while being compressed, gradually conforming to the contact surface of the central tube assembly 1 or the casing and well wall.

[0044] In some embodiments of this application, a pressure plate 5 is also included. The pressure plate 5 is connected to the central tube assembly 1 by fixing screws 6. The pressure plate 5 abuts against the outer wall of at least a portion of the upper slip 314, such as... Figure 5 As shown, the pressure plate 5 is a flat or curved rigid structural component, which is rigidly connected to the central tube assembly 1 by fixing screws 6. It is located on the outside of the upper cone 311 and the upper slip 314 and is in contact with the outer wall surface of the upper slip 314.

[0045] The main function of the pressure plate 5 is to prevent the center tube assembly 1 from rotating axially relative to the anchoring assembly 3 during the drilling and unsealing phase of the permanent packer. When the drill bit applies rotational torque and axial force from below, the pressure plate 5 maintains a relatively fixed positional relationship between the center tube assembly 1 and the upper slip 314 through rigid coupling with the center tube assembly 1 and contact constraint with the upper slip 314, preventing the mandrel of the center tube assembly 1 from rotating with the drill bit during drilling and thus becoming impossible to drill.

[0046] The pressure plate 5 does not directly participate in the setting and sealing actions. During the setting process, the driving force is transmitted from the driving assembly 2 to the anchoring assembly 3 via the locking assembly 4. The upper slip 314 expands radially along the conical surface of the cone, engaging the tubing to form a seal and anchor. The presence of the pressure plate 5 does not change the anchoring characteristics of the slip or the direction and magnitude of the driving force transmission.

[0047] The fixing screw 6 can be connected by threaded fastening, pinning, or welding to ensure long-term load-bearing capacity during drilling without loosening. A low-friction coating or wear-resistant gasket can be applied between the pressure plate 5 and the upper slip 314 to extend service life.

[0048] The packer has a central tube assembly 1 as its main frame, with a drive assembly 2, an anchoring assembly 3 and a locking assembly 4 arranged sequentially on the outer periphery. The drive assembly 2 is used to generate axial driving force by utilizing the pressure difference formed by the downhole fluid, thereby driving the anchoring assembly 3 to abut against the internal channel of the tubing or its mating interface and form a blockage of the internal channel. The locking assembly 4 is used to restrict the reverse movement of the anchoring assembly 3 and its related connecting parts after the sealing / setting is completed, so as to prevent the abutment relationship from changing due to fluctuations in external load.

[0049] When the packer is lowered into the well and reaches the working depth, the downhole annular hydrostatic pressure continues to increase with the well depth. If the pressure exceeds the preset rupture threshold of the rupture plate 218, the rupture plate 218 will be crushed and the flow channel will be opened. The high-pressure downhole fluid will then enter the sealing chamber and, under the pressure of the chamber, cause the third shear pin 217 to shear fracture. After the third shear pin 217 is cut, the lower piston sleeve 211 loses its shear lock on its movement and begins to move upward under the action of downhole fluid thrust. As the lower piston sleeve 211 moves upward, the limiting block 214 is released and reaches the avoidance position 215, thereby releasing the relative restriction between the lower piston sleeve 211 and the upper structure. At this time, the lower piston sleeve 211 moves upward and comes into contact with the upper piston sleeve 212 to transmit force, so that the upper piston sleeve 212 continues to transmit the axial driving force transmitted by the lower piston sleeve 211 upward until the connecting sleeve 41 comes into contact with / is subjected to force and moves upward accordingly. Then, through the driving action of the connecting sleeve 41, the anchoring assembly 3 is driven to expand the slip and squeeze and expand the sealing rubber sleeve assembly to complete the sealing of the internal channel. When performing standby hydraulic setting, if the main hydrostatic trigger fails to complete, the fluid in the central tube assembly 1 can be pressurized through the internal channel of the central tube assembly 1 to enter the drive chamber through the pressure transmission hole 222. After the pressure in the drive chamber is established, the connecting sleeve 41 is pushed upward until the contact is completed. The locking state of "pushable, reverse blocked" is achieved by the one-way stop cooperation between the locking tooth 43 and the locking ring 44. Under the aforementioned locking conditions, the slips in the anchoring assembly 3 are driven and expand outward to engage, causing the sealing sleeve assembly to continuously expand and adhere to form a sealing seal. At the same time, the locking assembly 4 ensures that the seal does not retract under reverse load after setting, thereby maintaining the sealing effect.

[0050] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0051] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A permanent hydrostatic packer, characterized in that, The device includes a central tube assembly (1) and a drive assembly (2), an anchoring assembly (3) and a locking assembly (4) connected to the central tube assembly (1). The drive assembly (2) is used to drive the anchoring assembly (3) by the downhole fluid pressure differential, so that the anchoring assembly (3) abuts against the internal passage of the tubing to form a blockage of the internal passage. The locking assembly (4) is used to restrict the direction of movement of the anchoring assembly (3).

2. The permanent hydrostatic packer according to claim 1, characterized in that, The locking component (4) includes: The connecting sleeve (41) is slidably sleeved on the central tube assembly (1); Locking ring seat (42) is connected to the connecting sleeve (41); Locking teeth (43) are distributed on the outer wall of the central tube assembly (1); The locking ring (44) is connected to the locking ring seat (42) and forms a one-way stop engagement with the locking tooth (43).

3. The permanent hydrostatic packer according to claim 2, characterized in that, The drive assembly (2) includes a dual-piston drive component (21) and an internal hydraulic drive component (22) disposed on the central tube assembly (1).

4. The permanent hydrostatic packer according to claim 3, characterized in that, The dual-piston drive component (21) includes: The lower piston sleeve (211) is slidably sleeved on the central tube assembly (1), and the lower piston sleeve (211) and at least a portion of the outer wall of the central tube assembly (1) form a first piston cavity; The upper piston sleeve (212) is slidably sleeved on the central tube assembly (1) and is connected to the connecting sleeve (41) and abuts against the lower piston sleeve (211). The upper piston sleeve (212) and at least a portion of the outer wall of the central tube assembly (1) form a second piston cavity. The first piston chamber and the second piston chamber are arranged along the axial direction of the central tube assembly (1). Under the action of the downhole fluid pressure difference, they are used to generate axial driving force on the lower piston sleeve (211) and the upper piston sleeve (212) and transmit the axial driving force to the connecting sleeve (41).

5. The permanent hydrostatic packer according to claim 4, characterized in that, Also includes: The stepped portion (213) is connected to the upper piston sleeve (212); A limiting block (214) is disposed through the stepped portion (213), and the limiting block (214) abuts against the central tube assembly (1) and the lower piston sleeve (211) respectively; The clearance station (215) is located on the lower piston sleeve (211) and is used to accommodate the limiting block (214).

6. The permanent hydrostatic packer according to claim 3, characterized in that, The internal hydraulic drive component (22) includes: A protrusion (221) is connected to the central tube assembly (1), wherein the protrusion (221), the connecting sleeve (41), the upper piston sleeve (212) and the central tube assembly (1) together form a driving cavity; The pressure transmission hole (222) is in communication with the drive cavity.

7. The permanent hydrostatic packer according to claim 1, characterized in that, The anchoring assembly (3) includes a plurality of anchoring members (31) and sealing members (32), the sealing members (32) being located between adjacent anchoring members (31).

8. The permanent hydrostatic packer according to claim 7, characterized in that, The anchoring member (31) includes: The upper vertebral body (311) and the lower vertebral body (312) are respectively connected to the central tube assembly (1) by a first shear pin (313); Upper slip (314) and lower slip (315) are connected to the upper vertebra (311) and the lower vertebra (312) respectively by a second shear pin (316).

9. The permanent hydrostatic packer according to claim 8, characterized in that, The sealing component (32) includes a sealing sleeve assembly, which is mounted on the central tube assembly (1) and located between the upper cone (311) and the lower cone (312).

10. The permanent hydrostatic packer according to claim 8, characterized in that, It also includes a pressure plate (5), which is connected to the central tube assembly (1) by a fixing screw (6), and the pressure plate (5) abuts against at least a portion of the outer wall of the upper slip (314).

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