A packer

Abstract

This utility model discloses a packer, belonging to the packer device category, comprising a setting mechanism and a release mechanism. The setting mechanism includes a central tube and an upper piston and a lower piston sleeved on the central tube; the upper and lower pistons are axially movable along the central tube to generate a setting thrust. The release mechanism includes a release connector connected to the central tube and a connecting sleeve connecting the release connector to the packer body; the outer wall of the connecting sleeve is threaded to the release connector, and the inner wall of the connecting sleeve is connected to the packer body via an elastic ring. The packer body is equipped with a release shear pin for limiting the elastic ring, located at the lower end of the connecting sleeve; wherein, the elastic ring expands under pressure to lock the connecting sleeve to the packer body, and when the setting thrust pushes the connecting sleeve to cut the release shear pin, the elastic ring is released, allowing the connecting sleeve to disengage from the packer body. This utility model improves the release capability of the packer through a dual mechanism of pressure release and rotational release.

Description

Technical Field

[0001] This utility model relates to the field of packer equipment technology, and in particular to a packer. Background Technology

[0002] Packers are essential tools in the oil and gas extraction industry. Their main function is to effectively isolate different oil, gas, and water layers inside the wellbore, preventing the cross-flow of fluids between layers, thereby ensuring the smooth implementation of processes such as layered extraction, layered water injection, and layered testing.

[0003] In practical use, a conventional packer is first lowered into the wellbore along with the tubing string to a predetermined position. Once in position, a specific operation causes the packer's sealing components to expand and tightly adhere to the wellbore wall, achieving isolation between different sections; this process is called setting. After setting, to allow the packer to remain in its predetermined downhole position and operate independently, a release operation is performed, separating the packer from the upper tubing string. After the corresponding mining operations are completed, the packer must be removed from the wellbore, requiring measures to restore the sealing components to their original state and release the seal against the wellbore wall.

[0004] However, when the downhole environment is characterized by high temperature and high pressure, or other complex stress environments or harsh conditions within the wellbore, the relevant components of the packer may deform due to prolonged exposure to high temperature and high pressure, leading to a decrease in the coordination accuracy of the release mechanism and making it difficult to perform the release operation smoothly. Utility Model Content

[0005] The purpose of this utility model is to provide a packer to solve the technical problem that existing packers are easy to lose control of in complex well environments.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] A packer for being lowered and seated inside a well casing, the packer comprising:

[0008] A setting mechanism includes a central tube and an upper piston and a lower piston sleeved on the central tube; the upper piston and the lower piston are movable along the axial direction of the central tube to generate a setting thrust.

[0009] A release mechanism is disposed below the sealing mechanism. The release mechanism includes a release connector connected to the central tube and a connecting sleeve connecting the release connector to the packer body. The outer wall of the connecting sleeve is threaded to the release connector, and the inner wall of the connecting sleeve is connected to the packer body through an elastic ring. The packer body is equipped with a release scissor pin for limiting the elastic ring, and the release scissor pin is located at the lower end of the connecting sleeve.

[0010] The elastic ring expands when compressed to lock the connecting sleeve to the packer body. When the seat seal thrust pushes the connecting sleeve to cut the release pin, the elastic ring releases, allowing the connecting sleeve to detach from the packer body.

[0011] Preferably, the sealing mechanism further includes a liquid inlet hole disposed on the central tube, the liquid inlet hole being used to introduce pressurized fluid to simultaneously drive the upper piston and the lower piston to move.

[0012] Preferably, the packer further includes a sealing mechanism, which is sleeved on the packer body. The seat sealing thrust can compress the sealing mechanism, causing the sealing mechanism to expand radially to seal the annulus between the packer body and the sleeve. The sealing mechanism includes a sand-proof rubber sleeve and a sealing rubber sleeve, with the sand-proof rubber sleeve located above the sealing rubber sleeve.

[0013] Preferably, the outer periphery of the packer body is provided with a seat sleeve that can slide axially. The seat sleeve is provided with a limiting end face. The lower end of the sandproof rubber tube abuts against the limiting end face, and the upper end of the sandproof rubber tube is connected to the lower piston, so that the lower piston can compress the sandproof rubber tube by applying the seat seal thrust.

[0014] Preferably, the lower piston is provided with a retaining ring, and the seat sleeve is provided with a retaining groove. When the lower piston moves and compresses the sandproof rubber sleeve to a preset position, the retaining ring is engaged in the retaining groove to lock the relative position between the lower piston and the seat sleeve, and to transmit the subsequent seat seal thrust to the seat sleeve.

[0015] Preferably, the lower end face of the seat cover abuts against the upper part of the sealing tube, and the outer periphery of the sealing tube is provided with a plurality of spacer rings to divide the sealing tube into a plurality of interconnected sealing units.

[0016] Preferably, the packer further includes an anchoring mechanism, which is sleeved on the packer body. The anchoring mechanism includes anchoring slips, which can generate radial expansion when the anchoring slips are subjected to the sealing thrust to anchor the packer body to the inner wall of the sleeve.

[0017] Preferably, the anchoring mechanism further includes a cone, which is linked to the lower piston. The anchoring slips are multiple and arranged circumferentially. A connecting gap is formed between the anchoring slips and the packer body. The width of the connecting gap gradually decreases along the axial direction of the packer body. The side of the cone near the anchoring slip can extend into the connecting gap and push against the anchoring slip, so that the anchoring slip expands radially.

[0018] Preferably, the device also includes an unsealing mechanism, which includes an unsealing connector, unsealing pins, and a locking block. An outer core tube is slidably connected to the packer body. An unsealing pin for limiting the outer core tube is disposed on the packer body. A slip seat is provided at the end of the anchoring slip away from the cone. The locking block is used to lock the outer core tube to the slip seat. An unsealing connector is provided at the upper end of the packer body.

[0019] When the unsealing connector is lifted, the unsealing shear pin is cut off, the locking block is released, and the outer core tube pulls the cone upward, causing the anchoring slip to radially retract and reset.

[0020] Preferably, the sealing mechanism further includes a locking ring and a locking sleeve;

[0021] The locking ring is sleeved outside the packer body, and the locking sleeve is sleeved outside the locking ring;

[0022] The locking ring and the locking sleeve are connected by a mutually cooperating one-way tooth structure, which allows the locking ring to expand radially under the action of the seat seal thrust, thereby moving downward in one direction relative to the locking sleeve and locking it to prevent reverse movement.

[0023] When the seat seal thrust is removed, the locking ring retracts radially, releasing the lock sleeve.

[0024] The beneficial effects of this utility model are:

[0025] The packer proposed in this invention adopts a double-piston structure consisting of an upper piston and a lower piston. The upper and lower pistons can move together axially along the central tube, thereby generating and superimposing their respective forces to form a total setting thrust, thus providing an effective setting thrust for the packer under harsh operating conditions. The setting thrust not only drives the setting mechanism to achieve the setting process, but also continues to be transmitted downwards to the release mechanism. In the release mechanism, the connecting sleeve and the release connector are connected by threads, and the connecting sleeve and the packer body are locked together by an elastic ring limited by a release shear pin. Under the action of the setting thrust, the elastic ring expands radially under pressure, locking the connecting sleeve and the packer body together, ensuring the stability of the setting process. When release is required, the setting thrust continues to be applied. When the setting thrust increases to a predetermined value and shears the release shear pin, the elastic ring depressurizes and contracts, immediately releasing the lock, thereby separating the connecting sleeve from the packer body and achieving release. Furthermore, if abnormal well conditions obstruct the pressure release channel or prevent the shear pin from cutting off, the operator can rotate the central tube via surface equipment to transmit torque to the release connector. Since the connecting sleeve and the release connector are directly threaded, they can be separated by unscrewing the threads, thus forcibly completing the release operation. In summary, this invention, through the dual mechanisms of pressure release and rotational release, constitutes a redundant system with mutual backups, enhancing the packer's release capability in the face of uncertain downhole risks, ensuring operational safety and the smooth implementation of subsequent processes. Attached Figure Description

[0026] Figure 1 This is a first structural schematic diagram of the packer provided in this embodiment of the utility model;

[0027] Figure 2 This is a schematic diagram of the second structure of the packer provided in this embodiment of the utility model;

[0028] Figure 3 yes Figure 2 Enlarged view of point A in the middle;

[0029] Figure 4 yes Figure 2 Enlarged view of point B in the middle;

[0030] Figure 5 yes Figure 2 Enlarged view of point C in the middle;

[0031] Figure 6 yes Figure 2 Enlarged view of point D in the middle.

[0032] In the picture:

[0033] 100. Sleeve;

[0034] 1. Sealing mechanism; 11. Central tube; 111. Liquid inlet; 12. Upper piston; 13. Lower piston; 14. Snap ring; 15. Locking ring; 16. Locking sleeve;

[0035] 2. Drop mechanism; 21. Drop connector; 22. Connecting sleeve; 23. Elastic ring; 24. Drop clip;

[0036] 3. Packer body; 31. Seat sleeve; 311. Limiting end face; 312. Slot; 32. Outer core tube; 33. Unsealing shear pin;

[0037] 4. Sealing mechanism; 41. Sandproof rubber sleeve; 42. Sealing rubber sleeve; 421. Spacer ring; 422. Sealing unit;

[0038] 5. Anchoring mechanism; 51. Anchoring slip; 52. Cone; 53. Connecting gap; 54. Slip seat;

[0039] 6. Unsealing mechanism; 61. Unsealing connector; 62. Locking block. Detailed Implementation

[0040] The embodiments of this utility model are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar parts or parts having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0041] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium; or the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0042] In the description of this utility model, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0043] The technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.

[0044] See Figures 1 to 6 The packer provided in this embodiment of the utility model is used to be lowered and seated inside the casing 100 in the well. The packer includes a setting mechanism 1 and a release mechanism 2. The sealing mechanism 1 includes a central tube 11 and an upper piston 12 and a lower piston 13 sleeved on the central tube 11. The upper piston 12 and the lower piston 13 can move axially along the central tube 11 to generate a sealing thrust. The release mechanism 2 is located below the sealing mechanism 1. The release mechanism 2 includes a release connector 21 connected to the central tube 11 and a connecting sleeve 22 connecting the release connector 21 to the packer body 3. The outer wall of the connecting sleeve 22 is threadedly connected to the release connector 21, and the inner wall of the connecting sleeve 22 is connected to the packer body 3 through an elastic ring 23. The packer body 3 is equipped with a release shear pin 24 for limiting the elastic ring 23. The release shear pin 24 is located at the lower end of the connecting sleeve 22. The elastic ring 23 expands when compressed to lock the connecting sleeve 22 to the packer body 3. When the sealing thrust pushes the connecting sleeve 22 to cut the release shear pin 24, the elastic ring 23 is released to disengage the connecting sleeve 22 from the packer body 3.

[0045] The packer proposed in this utility model adopts a double-piston structure consisting of an upper piston 12 and a lower piston 13. The upper piston 12 and the lower piston 13 can move together along the axial direction of the central tube 11, thereby generating and superimposing their respective forces to form a total setting thrust, thus providing an effective setting thrust for the packer under harsh operating conditions. The setting thrust is not only used to drive the setting mechanism 1 to realize the setting process, but also can continue to be transmitted downward to the release mechanism 2. In the release mechanism 2, the connecting sleeve 22 and the release connector 21 are connected by threads, and the connecting sleeve 22 and the packer body 3 are locked together by an elastic ring 23 limited by the release shear pin 24. Under the action of the setting thrust, the elastic ring 23 is compressed and expands radially, locking the connecting sleeve 22 and the packer body 3 together, ensuring the stability of the setting process. When release is required, the setting thrust continues to be applied. When the setting thrust increases to a predetermined value and shears the release shear pin 24, the elastic ring 23 depressurizes and contracts, immediately releasing the lock, thereby separating the connecting sleeve 22 from the packer body 3 and achieving release. Furthermore, if abnormal well conditions cause obstruction of the pressure release channel or failure of the shear pin to shear, the operator can rotate the central tube 11 via surface equipment to transmit torque to the release connector 21. Since the connecting sleeve 22 and the release connector 21 are directly threaded, they can be separated by unscrewing the threads, thus forcibly completing the release operation. In summary, this invention, through the dual mechanisms of pressure release and rotation release, constitutes a redundant system with mutual backups, improving the packer's release capability in the face of uncertain downhole risks, ensuring operational safety and the smooth implementation of subsequent processes.

[0046] The working principle and specific structure of the packer will be explained in detail below.

[0047] The central tube 11 is a hollow tube column, serving as a channel for pressurized fluid and the pressure-bearing body of the entire tool. An upper piston 12 and a lower piston 13 are sleeved along a specific axial direction of the central tube 11.

[0048] The sealing mechanism 1 also includes a liquid inlet 111 provided on the central tube 11, which is used to introduce pressurized fluid to simultaneously drive the upper piston 12 and the lower piston 13 to move.

[0049] Specifically, the inlet port 111 is typically one or more radial through holes. After the packer is lowered to the predetermined position in the well, pressurized fluid is injected into the central tube 11 from the surface through the tubing string. The pressurized fluid simultaneously enters the chambers of the upper piston 12 and the lower piston 13 through the inlet port 111. Due to the sealed design of the piston chambers, the pressurized fluid acts simultaneously on the pressure-bearing surfaces of the upper piston 12 and the lower piston 13, pushing them to move in the same direction along the axial direction of the central tube 11. The principle of this dual-piston design is that it can convert fluid pressure into mechanical thrust at two locations, and then superimpose these two thrusts to generate a much stronger sealing thrust than a single-piston structure.

[0050] Furthermore, to ensure the sealing state can be maintained for a long time and to prevent the sealing mechanism 4 from retracting and failing under downhole pressure fluctuations, the sealing mechanism 1 also includes a locking ring 15 and a locking sleeve 16; the locking ring 15 is sleeved outside the packer body 3, and the locking sleeve 16 is sleeved outside the locking ring 15. The locking ring 15 is usually made of a radially expandable brittle material or a grooved elastic metal, and the outer surface of the locking ring 15 and the inner surface of the locking sleeve 16 are provided with a mutually cooperating one-way tooth structure.

[0051] The locking ring 15 and the locking sleeve 16 are connected by a mutually cooperating one-way tooth structure, which causes the locking ring 15 to expand radially under the action of the seat seal thrust, thereby moving downward in one direction relative to the locking sleeve 16 and locking it to prevent reverse movement.

[0052] Its working principle is as follows: Under the action of the sealing thrust, the locking ring 15 is axially compressed and radially expanded, causing its one-way teeth to mesh tightly with the one-way teeth on the inner wall of the locking sleeve 16. Due to the one-way nature of the teeth, the locking ring 15 can move smoothly downwards, but when it attempts to move upwards, the tooth surfaces will jam against each other. Under friction and radial constraint, the locking ring 15 further tightens, forming a self-locking mechanism, thereby locking the sealing thrust. When the sealing thrust is removed, the locking ring 15 contracts radially, releasing the lock on the locking sleeve 16. When it is necessary to release the packer, a reverse force is applied by lifting the tubing, etc., to remove the sealing thrust, causing the meshing teeth between the locking ring 15 and the locking sleeve 16 to disengage. The locking ring 15 can then contract radially, releasing the locked state and creating conditions for subsequent release operations.

[0053] The packer also includes a sealing mechanism 4, which is sleeved on the packer body 3. The sealing thrust can compress the sealing mechanism 4, causing the sealing mechanism 4 to expand radially to seal the annular space between the packer body 3 and the sleeve 100. The sealing mechanism 4 includes a sand-proof rubber sleeve 41 and a sealing rubber sleeve 42, with the sand-proof rubber sleeve 41 located above the sealing rubber sleeve 42.

[0054] A seated sleeve 31, which can slide axially, is provided on the outer periphery of the packer body 3. The seated sleeve 31 can slide along the axial direction of the packer body 3. As a force transmission component, the inner wall of the seated sleeve 31 and the outer wall of the packer body 3 form a relatively sliding fit. A limiting end face 311 is provided on the seated sleeve 31. The lower end of the sandproof rubber tube 41 abuts against the limiting end face 311, and the upper end of the sandproof rubber tube 41 is connected to the lower piston 13, so that the lower piston 13 can compress the sandproof rubber tube 41 by applying a seated thrust.

[0055] Its working principle is that when the setting process is started, the lower piston 13 moves downward under the drive of the pressure fluid, and the lower end face of the lower piston 13 presses directly or indirectly against the upper end of the sandproof rubber sleeve 41. Since the lower end of the sandproof rubber sleeve 41 is supported by the limiting end face 311 of the setting sleeve 31, when the lower piston 13 continues to move downward, the sandproof rubber sleeve 41 will expand radially due to axial compression.

[0056] To ensure that the sandproof rubber sleeve 41 can maintain its shape stably after being compressed to the desired position and to fully transfer the subsequent sealing thrust to the lower sealing rubber sleeve 42, a retaining spring 14 is provided on the lower piston 13 and a retaining groove 312 is provided on the seat sleeve 31. When the lower piston 13 moves and compresses the sandproof rubber sleeve 41 to the preset position, the retaining spring 14 is engaged in the retaining groove 312 to lock the relative position between the lower piston 13 and the seat sleeve 31 and to transfer the subsequent sealing thrust to the seat sleeve 31.

[0057] The retaining ring 14 is typically made of a resilient metal material and may initially be in a compressed state. When the sand-resistant rubber sleeve 41 is compressed to the designed preset thickness or the lower piston 13 reaches the predetermined stroke, the retaining ring 14 on the lower piston 13 aligns precisely with the retaining groove 312 on the seat sleeve 31. Under its own elastic force, the retaining ring 14 quickly springs into the retaining groove 312. This action mechanically achieves a rigid connection between the lower piston 13 and the seat sleeve 31, temporarily locking them into a single unit. Subsequently, the continuously increasing seat thrust will no longer be primarily used to further compress the sand-resistant rubber sleeve 41, but will instead be directly transmitted to subsequent components via the seat sleeve 31 through this newly formed unit, achieving automatic conversion of the thrust transmission path and optimizing force transmission efficiency.

[0058] The sealing thrust is transmitted downwards through the sealing sleeve 31, with the lower end face of the sealing sleeve 31 abutting against the upper part of the sealing rubber tube 42. To improve the air bulging phenomenon that may occur in the middle and poor sealing at both ends of a single long rubber tube under pressure, and to improve its adaptability in irregular wellbore, multiple spacer rings 421 are spaced apart on the outer periphery of the sealing rubber tube 42. The multiple spacer rings 421 are sleeved on the packer body 3 and located between the sealing sleeve 31 and the fixed pressure bearing member below, serving to divide the sealing rubber tube 42 into multiple interconnected sealing units 422. The sealing rubber tubes 42 between each spacer ring 421 form an independent sealing unit 422.

[0059] When the axial sealing thrust is transmitted through the sealing sleeve 31 and the spacer ring 421, each sealing unit 422 is compressed sequentially and independently. Due to the incompressibility and fluidity of the rubber material, the rubber sleeve material within each sealing unit 422 expands radially outward. Even if the wall of the sleeve 100 where a unit is located is slightly concave or irregular, adjacent sealing units 422 in intact sections of the sleeve 100 can still establish an effective seal. The series operation of multiple sealing units 422 improves the reliability and pressure resistance of the sealing rubber sleeve 42. Ultimately, all sealing units 422 work together to achieve a tight seal between the packer body 3 and the sleeve 100.

[0060] The packer also includes an anchoring mechanism 5. The anchoring mechanism 5 is fitted onto the packer body 3 and includes anchor slips 51. When the anchor slips 51 are subjected to a setting thrust, they expand radially to anchor the packer body 3 to the inner wall of the casing 100. The fundamental principle is that the anchor slips 51 convert the enormous axial thrust generated during the setting process into a driving force that causes them to expand radially. This allows the teeth on the anchor slips 51 to engage with the inner wall of the casing 100, forming a mechanical anchoring action. This effectively prevents the packer from shifting due to changes in tubing stress during subsequent water injection, fracturing, or production processes.

[0061] Specifically, the anchoring mechanism 5 also includes a cone 52, which is linked to the lower piston 13. Multiple anchoring slips 51 are arranged circumferentially, typically consisting of three or more slips forming a ring, evenly distributed around the packer body 3. A connecting gap 53 is formed between the anchoring slips 51 and the packer body 3, the width of which gradually decreases along the axial direction of the packer body 3. The connecting gap 53 is wedge-shaped or trapezoidal in cross-section. The side of the cone 52 closest to the anchoring slip 51 can extend into the connecting gap 53 and push against the anchoring slip 51, causing the anchoring slip 51 to expand radially. Its working principle is that when the lower piston 13 moves downward under the action of the seat seal thrust, it drives the cone 52, which is linked to it, to move downward together. The conical inclined surface of the cone 52 then squeezes into the gradually narrowing connecting gap 53 formed by the inner surface of the anchoring slip 51 and the outer surface of the packer body 3. As the cone 52 continues to penetrate deeper, the wedge effect causes the anchoring slip 51 to be subjected to a huge radial outward force, forcing all the circumferentially arranged slips to expand outward synchronously until the carbide teeth on their outer surfaces firmly bite into the inner wall of the sleeve 100, thus completing the anchoring.

[0062] When the downhole operation is completed and the packer needs to be removed, the packer also includes a release mechanism 6, which includes a release connector 61, a release shear pin 33, and a locking block 62. An outer core tube 32 is slidably connected to the packer body 3, and the outer core tube 32 is connected to or can act on the cone 52. The packer body 3 is equipped with a release shear pin 33 for limiting the outer core tube 32, ensuring that the outer core tube 32 remains relatively fixed to the packer body 3 during setting and production. A slip seat 54 is provided at the end of the anchor slip 51 away from the cone 52, and the locking block 62 is used to lock the outer core tube 32 to the slip seat 54. In the setting state, the locking block 62 is located within the annulus between the outer core tube 32 and the slip seat 54, making them a single unit that jointly bears the reaction force from the anchor slip 51. The packer body 3 is provided with a release connector 61 at the upper end, which is connected to the downhole retrieval tool or directly to the lifting string.

[0063] The unsealing operation is as follows: When the unsealing connector 61 is lifted, the lifting force acts directly on the packer body 3 through the unsealing connector 61. Since the anchoring slip 51 is still engaged with the sleeve 100, there is a relative movement tendency between the packer body 3 and the external anchoring mechanism 5 and the outer core tube 32 in the initial stage. When this lifting force increases to a preset value, the unsealing shear pin 33 is sheared, thereby releasing the axial constraint on the outer core tube 32. At the same time, with the occurrence of relative movement, the geometry of the annular space where the locking block 62 is located changes, and the locking block 62 is released and falls off from its original locked position. After the locking block 62 falls off, the mechanical connection between the outer core tube 32 and the slip seat 54 is released. Continuing to lift the string, the outer core tube 32 pulls the cone 52 upward, causing the cone 52 to exit from the wedge-shaped connection gap 53 that forces the anchoring slip 51 to expand. Once the supporting effect of the cone 52 disappears, the anchoring slip 51 radially retracts and resets, and its teeth disengage from the inner wall of the casing 100, releasing the anchoring. After the anchoring is released, the entire packer can move smoothly under the action of the lifting force, creating conditions for the subsequent complete removal of the wellbore.

[0064] The operation process of the packer is described in detail below.

[0065] After the packer is lowered to the predetermined depth of the casing 100 in the well through the tubing string, pressurized fluid is pumped from the surface into the central tube 11. The pressurized fluid enters the chambers of the upper piston 12 and the lower piston 13 simultaneously through the inlet port 111 on the central tube 11, driving the upper piston 12 and the lower piston 13 to move axially along the central tube 11. The dual piston structure works together to generate and superimpose a powerful setting thrust.

[0066] The sealing thrust first acts on the sealing mechanism 4 and the anchoring mechanism 5. The sealing thrust pushes the lower piston 13 downward, compressing the sand-proof rubber sleeve 41 located below the lower piston 13. The lower end of the sand-proof rubber sleeve 41 is supported by the limiting end face 311 of the sealing sleeve 31, thus causing radial expansion and initially playing a sand-proof role. When the lower piston 13 moves to the preset position, the retaining ring 14 on the lower piston 13 engages with the retaining groove 312 of the sealing sleeve 31, locking the lower piston 13 and the sealing sleeve 31 into one unit, so that the subsequent thrust can be efficiently transmitted through the sealing sleeve 31. The lower end face of the sealing sleeve 31 then compresses the sealing rubber sleeve 42 below. The sealing rubber sleeve 42 is divided into several sealing units 422 by multiple spacers 421. Under the axial sealing thrust, each sealing unit 422 expands radially independently, tightly fitting the inner wall of the sleeve 100, forming a multi-stage redundant high-pressure seal, effectively sealing the spacers 421.

[0067] Simultaneously, the cone 52, linked to the lower piston 13, moves downward under thrust. The conical surface of the cone 52 is squeezed into the gradually narrowing connecting gap 53 between the anchoring slips 51 and the packer body 3. The wedge effect forces the circumferentially arranged multiple anchoring slips 51 to expand radially. The hard alloy teeth on the surface of the anchoring slips 51 are forcefully embedded into the inner wall of the sleeve 100, achieving mechanical anchoring and preventing the packer from shifting during operation. To ensure a durable setting state, the setting thrust simultaneously drives the locking ring 15 to move unidirectionally downward within the locking sleeve 16 and lock. The unidirectional tooth structure between the locking ring 15 and the locking sleeve 16 forms a mechanical self-locking mechanism, preventing the sealing element from springing back and firmly maintaining the setting state.

[0068] After the setting process stabilizes, the release operation is immediately initiated. The continuously applied setting thrust is transmitted downwards to the release mechanism 2. The setting thrust causes the elastic ring 23 inside the connecting sleeve 22 to expand radially under pressure, tightly locking the connecting sleeve 22 to the packer body 3. When the thrust increases to a predetermined value, the release shear pin 24 is sheared, the elastic ring 23 depressurizes and contracts, the locking effect is instantly released, and the connecting sleeve 22 disengages from the packer body 3, achieving pressure release. This allows the packer body 3 to be independently anchored and sealed downhole, while the center tube 11 can be easily retrieved. If pressure release fails due to abnormal well conditions, the backup plan is activated. The center tube 11 is rotated via surface equipment, and the torque is transmitted through the release connector 21, directly unscrewing the threaded connection between it and the connecting sleeve 22 to complete the rotation release. This dual-mode pressure and rotation release mechanism constitutes a reliable redundant system.

[0069] When the packer needs to be retrieved after downhole operations are completed, the unsealing procedure is initiated. The unsealing connector 61 is lifted using a retrieval tool or tubing string. The initial lifting force acts on the packer body 3 due to the engagement of the anchor slips 51. When the lifting force reaches a preset value, the unsealing shear pin 33 is sheared, releasing the constraint on the outer core tube 32. Subsequently, the locking block 62 is released and dislodged due to relative movement, releasing the lock between the outer core tube 32 and the slip seat 54. Continuing to lift, the outer core tube 32 drives the cone 52 upward, causing it to exit from the connection gap 53 of the anchor slips 51. Without the support of the cone 52, the anchor slips 51 radially contract and reset under their own elasticity or external force, their teeth disengaging from the inner wall of the casing 100, releasing the anchoring. Simultaneously, the lifting force overcomes the self-locking between the locking ring 15 and the locking sleeve 16, causing the locking ring 15 to radially contract, releasing the lock on the seated state, and the sealing mechanism 4 returns to its original state. Finally, the packer, now freed from anchoring and sealing, can be successfully pulled out of the wellbore under lifting force.

[0070] In summary, this packer, through the orderly linkage and coordinated cooperation of its setting, release, and unsealing mechanisms 6, achieves a complete operational cycle of reliable setting, safe release, and smooth unsealing under complex well conditions, effectively solving the technical problem of difficult release in existing technologies.

[0071] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A packer for running in and setting in a casing (100) in a well, characterized in that, include: The sealing mechanism (1) includes a central tube (11) and an upper piston (12) and a lower piston (13) sleeved on the central tube (11); the upper piston (12) and the lower piston (13) are capable of moving along the axial direction of the central tube (11) to generate a sealing thrust; The release mechanism (2) is located below the sealing mechanism (1). The release mechanism (2) includes a release connector (21) connected to the central tube (11) and a connecting sleeve (22) connecting the release connector (21) to the packer body (3). The outer wall of the connecting sleeve (22) is threaded to the release connector (21), and the inner wall of the connecting sleeve (22) is connected to the packer body (3) through an elastic ring (23). The packer body (3) is provided with a release scissor pin (24) for limiting the elastic ring (23). The release scissor pin (24) is located at the lower end of the connecting sleeve (22). The elastic ring (23) expands when compressed to lock the connecting sleeve (22) and the packer body (3). When the seat seal thrust pushes the connecting sleeve (22) to cut the release scissor nail (24), the elastic ring (23) is released so that the connecting sleeve (22) is separated from the packer body (3).

2. The packer according to claim 1, characterized in that, The sealing mechanism (1) further includes a liquid inlet (111) provided on the central tube (11), the liquid inlet (111) being used to introduce pressurized fluid to simultaneously drive the upper piston (12) and the lower piston (13) to move.

3. The packer of claim 1, wherein, The packer also includes a sealing mechanism (4), which is sleeved on the packer body (3). The seat sealing thrust can compress the sealing mechanism (4) to cause the sealing mechanism (4) to expand radially to seal the annulus between the packer body (3) and the sleeve (100). The sealing mechanism (4) includes a sand-proof rubber sleeve (41) and a sealing rubber sleeve (42), with the sand-proof rubber sleeve (41) located above the sealing rubber sleeve (42).

4. The packer of claim 3, wherein, The packer body (3) is provided with a seat sleeve (31) that can slide along the axial direction on its outer periphery. The seat sleeve (31) is provided with a limiting end face (311). The lower end of the sandproof rubber tube (41) abuts against the limiting end face (311). The upper end of the sandproof rubber tube (41) is connected to the lower piston (13), so that the lower piston (13) can compress the sandproof rubber tube (41) by applying the seat seal thrust.

5. The packer of claim 4, wherein, A retaining ring (14) is provided on the lower piston (13), and a retaining groove (312) is provided on the seat sleeve (31). When the lower piston (13) moves and compresses the sandproof rubber sleeve (41) to a preset position, the retaining ring (14) is engaged in the retaining groove (312) to lock the relative position between the lower piston (13) and the seat sleeve (31) and to transmit the subsequent seat sealing thrust to the seat sleeve (31).

6. The packer of claim 4, wherein, The lower end face of the seat cover (31) abuts against the upper part of the sealing tube (42). The outer periphery of the sealing tube (42) is provided with a plurality of spacers (421) to divide the sealing tube (42) into a plurality of interconnected sealing units (422).

7. The packer of claim 1, wherein, The packer also includes an anchoring mechanism (5), which is sleeved on the packer body (3). The anchoring mechanism (5) includes an anchoring slip (51), which can generate radial expansion to anchor the packer body (3) to the inner wall of the sleeve (100) when the anchoring slip (51) is subjected to the seat sealing thrust.

8. The packer of claim 7, wherein, The anchoring mechanism (5) also includes a cone (52), which is linked to the lower piston (13). The anchoring slips (51) are multiple and arranged circumferentially. A connecting gap (53) is formed between the anchoring slips (51) and the packer body (3). The width of the connecting gap (53) gradually decreases along the axial direction of the packer body (3). The side of the cone (52) near the anchoring slip (51) can extend into the connecting gap (53) and push against the anchoring slip (51) so that the anchoring slip (51) expands radially.

9. The packer of claim 8, wherein, It also includes a release mechanism (6), which includes a release connector (61), a release scissors (33) and a locking block (62). An outer core tube (32) is slidably connected to the packer body (3). The release scissors (33) for limiting the outer core tube (32) are arranged on the packer body (3). A slip seat (54) is provided at the end of the anchoring slip (51) away from the cone (52). The locking block (62) is used to lock the outer core tube (32) and the slip seat (54). The release connector (61) is provided at the upper end of the packer body (3). When the unsealing connector (61) is lifted, the unsealing shear (33) is cut off, the locking block (62) is released, and the outer core tube (32) pulls the cone (52) upward, causing the anchoring slip (51) to radially retract and reset.

10. The packer of claim 1, wherein, The sealing mechanism (1) further includes a locking ring (15) and a locking sleeve (16). The locking ring (15) is sleeved outside the packer body (3), and the locking sleeve (16) is sleeved outside the locking ring (15); The locking ring (15) and the locking sleeve (16) are connected by a mutually cooperating one-way tooth structure, so that the locking ring (15) expands radially under the action of the seat seal thrust, thereby moving downward in one direction relative to the locking sleeve (16) and locking it to prevent reverse movement; When the seat seal thrust is removed, the locking ring (15) retracts radially, releasing the lock sleeve (16).

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