A packer that can be repeatedly set and released by hydraulic action

Abstract

The present application relates to oil and gas well downhole tool technical field, especially to a packer which can be repeatedly set and released by hydraulic action, so as to relieve the problem of traditional mechanical packer slipping, sealing failure or falling when bearing bidirectional pressure. The limiting sleeve and rubber tube of the device are sequentially sleeved with the sandwich sleeve from top to bottom; the sandwich sleeve, the outer sleeve and the starting sleeve are sequentially sleeved with the center tube from top to bottom; the lower part of the limiting sleeve abuts against the rubber tube, and the lower part abuts against the convex part of the center tube; the outer sleeve and the starting sleeve are fixedly connected through the connecting sleeve; the starting sleeve and the center tube have a first cavity; the center tube is provided with a pressure transmission hole which is communicated with the first cavity. Through the hydraulic control mode, the setting and releasing are realized, the limitation that the mechanical setting packer one-way slip structure can only bear the single direction pressure is solved, and several times of setting and releasing can be realized without going out the packer for debugging, so that the work efficiency is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of downhole tools for oil and gas wells, and in particular to a packer that can be repeatedly set and unset using hydraulic action. Background Technology

[0002] Although mechanical packers are widely used in many oil and gas well operations, they have revealed some significant drawbacks in complex well conditions, especially in wells with large inclinations or those that need to withstand bidirectional pressure, which limits their application range and operational efficiency.

[0003] Firstly, mechanical pressure-down methods rely on tubing or weights to set the packer. However, in wells with significant inclination, especially when the inclination angle exceeds a certain critical value, traditional pressure-down methods often fail to guarantee accurate and stable packer setting. Because pressure in deviated wells can easily lose direction or deviate, this deviation can prevent the packer from effectively contacting the wellbore, thus failing to form a proper seal and hindering subsequent operations.

[0004] Secondly, existing mechanically set packers generally employ a unidirectional slip structure, where the slips secure the packer through friction with the wellbore. This unidirectional pressure-bearing design means the packer can only withstand pressure from one direction. In many working wells requiring bidirectional pressure, the unidirectional slip structure cannot provide sufficient stability and sealing capability. Especially in high-pressure and complex pressure environments, traditional packers often slip, fail to seal, or detach when subjected to bidirectional pressure, leading to downhole operation failures, increased well control risks, and potentially even serious accidents such as damage to downhole equipment or blowouts. Summary of the Invention

[0005] This invention provides a packer that can be repeatedly set and unsealed using hydraulic action, thereby alleviating the problems of slippage, seal failure, or detachment that occur when traditional mechanical packers are subjected to bidirectional pressure.

[0006] To alleviate the above-mentioned technical problems, the technical solution provided by the present invention is as follows:

[0007] This invention provides a packer that can be repeatedly set and unset using hydraulic action, including an upper connector, a central tube and a lower connector, as well as a sandwich sleeve, a limiting sleeve, a rubber tube, an outer sleeve, a starting sleeve and a connecting sleeve;

[0008] The limiting sleeve and the rubber sleeve are sequentially fitted onto the interlayer sleeve from top to bottom;

[0009] The interlayer sleeve, outer sleeve, and starting sleeve are sequentially connected to the central tube from top to bottom;

[0010] The lower part of the limiting sleeve abuts against the rubber tube, and the upper part abuts against the protrusion of the central tube;

[0011] The outer sleeve and the starting sleeve are fixedly connected by a connecting sleeve;

[0012] There is a first cavity between the starting sleeve and the central tube;

[0013] The central tube is provided with a pressure transmission hole that communicates with the first cavity.

[0014] Furthermore,

[0015] A slip assembly is installed between the rubber sleeve and the outer sleeve;

[0016] The slip assembly includes, from top to bottom, an upper cone, slips, and a lower cone that are sequentially fitted onto the jacketed sleeve;

[0017] The upper and lower parts of the kava each have a first slope;

[0018] The upper cone has a second inclined surface that mates with the first inclined surface;

[0019] The lower cone has a third inclined surface that matches the first inclined surface.

[0020] Furthermore,

[0021] The outer wall of the slip is fitted with a slip cover;

[0022] A first spring is provided between the slip cover and the slip;

[0023] The first spring is a compression spring, which always has the ability to drive the slip to move towards the center tube.

[0024] Furthermore,

[0025] It also includes a reset component;

[0026] The reset assembly includes a reset sleeve and a reset spring.

[0027] The upper part of the reset sleeve abuts against the upper connector, and the lower part is threadedly connected to the limit sleeve;

[0028] The reset spring is located between the central tube and the reset sleeve, with its upper part abutting against the reset sleeve and its lower part abutting against the protrusion.

[0029] Furthermore,

[0030] It also includes limit components;

[0031] The limiting assembly includes a limiting spring and a limiting ball;

[0032] The limiting spring is located in the groove of the central tube;

[0033] The limiting ball is fixedly connected to the end of the limiting spring furthest from the central tube;

[0034] The starting sleeve has a positioning hole that mates with the limit ball;

[0035] The lower part of the starting sleeve has a reset slope that cooperates with the limit ball.

[0036] Furthermore,

[0037] It also includes a split claw locking mechanism and an unlocking ring;

[0038] The split claw locking mechanism is located at the lower part of the lower cone and is sleeved with the central tube.

[0039] The unsealing ring is located at the lower part of the split claw locking mechanism and is fixedly connected to the central tube by a fixing pin;

[0040] A C-shaped ring is also installed between the unsealing ring and the central tube.

[0041] Furthermore,

[0042] During the setting process, pressure is applied to the central tube, and the pressure enters the second cavity through the pressure transmission hole. Under the action of the pressure, the connecting sleeve drives the outer sleeve and the starting sleeve to move upward.

[0043] As the starting sleeve moves upward, it squeezes the limiting ball, and the limiter is compressed towards the central tube, releasing the lock on the starting sleeve;

[0044] As the outer sleeve moves upward, it pushes the lower cone upward, causing the slip to move away from the central tube. At the same time, the upper cone squeezes the rubber sleeve, causing the rubber sleeve to expand under pressure, and the barbed threads inside the outer sleeve lock together with the barbed threads on the split claw locking mechanism.

[0045] Furthermore,

[0046] During unsealing, stop pressurizing the central tube and lift the tube column, causing the unsealing ring to move upward with the central tube and push the split claw locking mechanism to retract into the central tube, releasing the lock with the outer sleeve; at the same time, the rubber sleeve and slip return to their pre-setting state, and the limit ball is inserted into the positioning hole of the starting sleeve.

[0047] The beneficial effects of the packer in this invention, which utilizes hydraulic action for repeated setting and unsetting, are analyzed as follows:

[0048] This device includes a jacketed sleeve, a limiting sleeve, a rubber sleeve, an outer sleeve, a starting sleeve, and a connecting sleeve; the limiting sleeve and the rubber sleeve are sequentially fitted onto the jacketed sleeve from top to bottom; the jacketed sleeve, the outer sleeve, and the starting sleeve are sequentially fitted onto the central tube from top to bottom; the lower part of the limiting sleeve abuts against the rubber sleeve, and the lower part abuts against the protrusion of the central tube; the outer sleeve and the starting sleeve are fixedly connected by the connecting sleeve; a first cavity is provided between the starting sleeve and the central tube; the central tube is provided with a pressure transmission hole communicating with the first cavity.

[0049] This device uses hydraulic control to set and release the packer, avoiding problems such as slippage, seal failure, or detachment caused by bidirectional pressure. It solves the limitation of mechanically set packers with unidirectional slips that can only withstand pressure in one direction. Furthermore, it can achieve multiple setting and release operations without needing to remove the packer for debugging, greatly improving work efficiency. Attached Figure Description

[0050] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of the present invention, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0051] Figure 1 A schematic diagram of the unsealing process of a packer that can be repeatedly set and unsealed using hydraulic action, provided for an embodiment of the present invention;

[0052] Figure 2 This is a schematic diagram of the setting process of a packer that can be repeatedly set and unset using hydraulic action, provided as an embodiment of the present invention.

[0053] icon:

[0054] 100 - Central tube; 110 - Protrusion; 120 - Pressure transmission hole;

[0055] 200-Limit Sleeve;

[0056] 300-Glue Shot;

[0057] 400-outerwear sleeve;

[0058] 500 - Starting sleeve; 510 - Positioning hole; 520 - Reset bevel;

[0059] 600-Connecting sleeve;

[0060] 700 - Slip assembly; 710 - Upper cone; 720 - Slip; 730 - Lower cone; 740 - First spring;

[0061] 800 - Reset sleeve; 810 - Reset spring;

[0062] 900 - Limit spring; 910 - Limit ball;

[0063] 001 - First cavity;

[0064] 002 - Split-claw locking mechanism;

[0065] 003 - Unsealing Ring;

[0066] 004 - Fixing pin;

[0067] 005-C type ring. Detailed Implementation

[0068] Existing mechanically set packers generally employ a unidirectional slip structure, where the slips secure the packer through friction with the wellbore. This unidirectional pressure-bearing design means the packer can only withstand pressure from one direction. In many working wells requiring bidirectional pressure, the unidirectional slip structure cannot provide sufficient stability and sealing capability. Especially in high-pressure and complex pressure environments, traditional packers often slip, fail to seal, or detach under bidirectional pressure, leading to downhole operation failures, increased well control risks, and potentially even serious accidents such as downhole equipment damage or blowouts.

[0069] In view of this, such as Figure 1 and Figure 2 As shown, this solution provides a packer that can be repeatedly set and unset using hydraulic action, including an upper connector, a central tube 100 and a lower connector, as well as a sandwich sleeve 130, a limiting sleeve 200, a rubber sleeve 300, an outer sleeve 400, a starting sleeve 500 and a connecting sleeve 600.

[0070] The limiting sleeve 200 and the rubber sleeve 300 are sequentially sleeved with the interlayer sleeve 130 from top to bottom;

[0071] The interlayer sleeve 130, the outer sleeve 400, and the starting sleeve 500 are sequentially sleeved onto the central tube 100 from top to bottom;

[0072] The lower part of the limiting sleeve 200 abuts against the rubber sleeve 300, and the upper part abuts against the protrusion 110 of the central tube 100.

[0073] The outer sleeve 400 and the starting sleeve 500 are fixedly connected by the connecting sleeve 600;

[0074] There is a first cavity 001 between the starting sleeve 500 and the central tube 100;

[0075] The central tube 100 is provided with a pressure transmission hole 120 that communicates with the first cavity 001.

[0076] Specifically, during the setting process, the pressurization equipment on the well is connected to the upper connector, and pressure is applied into the central tube 100. The pressure enters the first cavity 001 through the pressure transmission hole 120, causing the connecting sleeve 500 to move upward, which in turn drives the outer sleeve 400 and the starting sleeve 500 to move upward. Then, pressure is applied to the lower side of the rubber sleeve 300 through the outer sleeve 400. The limiting sleeve 200 on the upper side of the rubber sleeve 300 restricts the upward movement of the rubber sleeve 300, thereby causing the rubber sleeve 300 to expand under pressure and fit against the well wall to form a setting seal.

[0077] In this design, a slip assembly 700 is provided between the rubber sleeve 300 and the outer sleeve 400;

[0078] The slip assembly 700 includes an upper cone 710, a slip 720, and a lower cone 730, which are sequentially fitted onto the jacket sleeve 130 from top to bottom;

[0079] The upper and lower parts of the Kava 720 each have a first slope;

[0080] The upper cone 710 has a second inclined surface that mates with the first inclined surface;

[0081] The lower cone 730 has a third inclined surface that mates with the first inclined surface;

[0082] The outer wall of the Kova 720 is fitted with a Kova cover;

[0083] A first spring 740 is provided between the slip cover and the slip 720;

[0084] The first spring 740 is a compression spring, which always has the ability to drive the slip 720 to move toward the central tube 100.

[0085] Specifically, in the initial state, the slip assembly 700 is vertically positioned between the rubber sleeve 300 and the outer sleeve 400. The slip 720 is in contact with the outer wall of the interlayer sleeve 130. When the outer sleeve 400 moves upward, it pushes the lower cone 710 to move. Because the slip 720 engages with the second inclined surface of the upper cone 710 and the third inclined surface of the lower cone 730 through the first inclined surface, with the second inclined surface gradually extending outward from bottom to top and the third inclined surface gradually extending outward from top to bottom, the slip... 720 moves away from the central tube 100. At the same time, the slip 720 and the upper cone 710 are directly connected through the slip cover. Therefore, as the slip 720 gradually extends outward, the upper cone 710 moves upward to squeeze the rubber cylinder 300. The slip cover can also limit the slip 720 to prevent it from over-expanding. At the same time, it is connected to the slip 720 through the first spring 740, so that when unsealing, it provides elastic force to the slip 720 and drives the slip 720 to return to the initial state.

[0086] This solution also includes a reset component;

[0087] The reset assembly includes a reset sleeve 800 and a reset spring 810.

[0088] The upper part of the reset sleeve 800 abuts against the upper connector, and the lower part is threadedly connected to the limit sleeve 200;

[0089] The reset spring 810 is disposed between the central tube 100 and the reset sleeve 800, with its upper part abutting against the reset sleeve 800 and its lower part abutting against the protrusion 110.

[0090] Specifically, during unsealing, the central tube 100 is lifted. To prevent the limiting sleeve 200 from moving downwards and affecting the unsealing effect, a reset spring 810 is set to provide an upward thrust to the limiting sleeve 200 at all times, ensuring that the limiting sleeve 200 is always in the correct position.

[0091] This solution also includes a limit switch component;

[0092] The limiting assembly includes a limiting spring 900 and a limiting ball 910;

[0093] The limiting spring 900 is disposed in the groove of the central tube 100;

[0094] The limiting ball 910 is fixedly connected to the end of the limiting spring 900 away from the center tube 100;

[0095] The starting sleeve 500 has a positioning hole 510 that mates with the limiting ball 910;

[0096] The lower part of the starting sleeve 500 has a reset slope 520 that cooperates with the limit ball 910.

[0097] Specifically, to prevent the device from erroneously triggering the setting seal during its entry into the well, thus affecting the well entry operation, a limiting component 900 is installed. During entry into the well, the starting sleeve 500 is locked by the engagement of the limiting ball 910 with the positioning hole 510. During setting, under pressure, the starting sleeve 500 moves upward while simultaneously pressing the limiting device 910 inward, causing the limiting spring 910 to contract, thereby allowing the limiting ball 910 to slide out of the positioning hole 510 and release the locking state. During unlocking, the starting sleeve 500 moves downward, and the reset slope 520 first pushes the limiting ball 910, causing the limiting spring 900 to contract, so that the starting sleeve 500 can continue to move downward. When the starting sleeve 500 moves to the initial position, the limiting ball 910 is directly facing the positioning hole 510. At this time, under the elastic force of the limiting spring 900, the limiting ball 910 is engaged in the positioning hole 510.

[0098] This solution also includes a split claw locking mechanism 002 and an unsealing ring 003;

[0099] The split claw locking mechanism 002 is located at the lower part of the lower cone 730 and is sleeved with the central tube 100.

[0100] The unsealing ring 003 is located at the lower part of the split claw locking mechanism 002 and is fixedly connected to the central tube 100 by the fixing pin 004;

[0101] A C-ring 005 is also provided between the unsealing ring 003 and the central tube 100.

[0102] Among them, the split claw locking mechanism 002 is a commonly used locking mechanism. The locking and unlocking methods of the split claw locking mechanism 002 are existing technologies, and their principles will not be described in detail.

[0103] In this scheme, when setting the seal, pressure is applied into the central tube 100, and the pressure enters the first cavity 001 through the pressure transmission hole 120. Under the action of pressure, the connecting sleeve 600 drives the outer sleeve 400 and the starting sleeve 500 to move upward.

[0104] As the starting sleeve 500 moves upward, it squeezes the limiting ball 910, and the limiter is compressed towards the center tube 100, thus releasing the lock on the starting sleeve 500.

[0105] During the upward movement of the outer sleeve 400, the lower cone 730 is pushed upward, causing the slip 720 to move away from the central tube 100; at the same time, the upper cone 710 squeezes the rubber tube 300, causing the rubber tube 300 to expand under pressure, and the barbed threads inside the outer sleeve 400 lock together with the barbed threads on the split claw locking mechanism 002.

[0106] In this scheme, when unsealing, the tube column is lifted, causing the unsealing ring 003 to move upward with the central tube 100, and pushing the split claw locking mechanism 002 to retract into the central tube 100, releasing the lock with the outer sleeve 400; at the same time, the rubber sleeve 300 and the slip 720 return to the state before setting, and the limit ball 910 is inserted into the positioning hole 510 of the starting sleeve 500.

[0107] This solution has at least the following beneficial effects:

[0108] 1. This solution employs an innovative hydraulic drive method, enabling reliable bidirectional pressure bearing during downhole operations. This overcomes the limitation of mechanically set packers, whose unidirectional slip structure can only withstand pressure in one direction. Through hydraulic control, the packer can operate stably under high pressure, avoiding slippage, seal failure, or detachment caused by bidirectional pressure. This significantly improves the safety and reliability of downhole operations. Furthermore, hydraulic setting and lifting of the packer allow for multiple setting and unsetting cycles downhole without requiring removal for adjustments.

[0109] 2. The packer features a rational structural design. The cooperation between the slip assembly and the rubber sleeve allows the packer to fit tightly against the wellbore, providing stronger sealing capabilities and avoiding common leakage problems in downhole operations. Furthermore, the slip assembly design ensures that the slips can smoothly separate and reset from the center tube under external force, guaranteeing that the packer can quickly return to its initial state upon unsealing, thereby improving operational flexibility and efficiency.

[0110] 3. Compared with packers that require repeated mechanical setting and unsetting, hydraulic control eliminates the need to consider the tonnage of the packer, thus having no requirements for well inclination or well depth.

[0111] 4. The packer can be set while installed at the wellhead, which can effectively avoid the well control risks that exist during the setting process of packers that have been mechanically set and unsealed repeatedly.

[0112] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A packer capable of repeated setting and unsetting using hydraulic action, comprising an upper connector, a central tube (100), and a lower connector, characterized in that: It includes a sandwich sleeve (130), a limiting sleeve (200), a rubber sleeve (300), an outer sleeve (400), a starting sleeve (500), and a connecting sleeve (600); The limiting sleeve (200) and the rubber sleeve (300) are sequentially sleeved with the interlayer sleeve (130) from top to bottom; The interlayer sleeve (130), the outer sleeve (400), and the starting sleeve (500) are sequentially sleeved with the central tube (100) from top to bottom; The lower part of the limiting sleeve (200) abuts against the rubber tube (300), and the upper part abuts against the protrusion (110) of the central tube (100); The outer sleeve (400) and the starting sleeve (500) are fixedly connected by a connecting sleeve (600); There is a first cavity (001) between the starting sleeve (500) and the central tube (100); The central tube (100) is provided with a pressure transmission hole (120) that communicates with the first cavity (001).

2. The packer with reversible setting and unsetting capabilities using hydraulic action according to claim 1, characterized in that: A slip assembly (700) is provided between the rubber sleeve (300) and the outer sleeve (400); The slip assembly (700) includes an upper cone (710), a slip (720), and a lower cone (730) that are sequentially fitted onto the interlayer sleeve (130) from top to bottom; The upper and lower parts of the kava (720) each have a first inclined surface; The upper cone (710) has a second inclined surface that mates with the first inclined surface; The lower cone (730) has a third inclined surface that cooperates with the first inclined surface.

3. The packer with reversible setting and unsetting capabilities using hydraulic action according to claim 2, characterized in that: The outer wall of the slip (720) is fitted with a slip cover; A first spring (740) is provided between the slip cover and the slip (720); The first spring (740) is a compression spring and always has the ability to drive the slip (720) to move toward the central tube (100).

4. The packer with reversible setting and unsetting capabilities using hydraulic action according to claim 3, characterized in that: It also includes a reset component; The reset assembly includes a reset sleeve (800) and a reset spring (810); The upper part of the reset sleeve (800) abuts against the upper connector, and the lower part is threadedly connected to the limiting sleeve (200); The reset spring (810) is disposed between the central tube (100) and the reset sleeve (800), with its upper part abutting against the reset sleeve (800) and its lower part abutting against the protrusion (110).

5. The packer with reversible setting and unsetting capabilities using hydraulic action according to claim 4, characterized in that: It also includes limit components; The limiting component includes a limiting spring (900) and a limiting ball (910); The limiting spring (900) is disposed in the groove of the central tube (100); The limiting ball (910) is fixedly connected to the end of the limiting spring (900) away from the central tube (100); The starting sleeve (500) has a positioning hole (510) that mates with the limiting ball (910); The lower part of the starting sleeve (500) has a reset slope (520) that cooperates with the limiting ball (910).

6. The packer with reversible setting and unsetting capabilities using hydraulic action according to claim 5, characterized in that: It also includes a split claw locking mechanism (002) and an unsealing ring (003); The split claw locking mechanism (002) is located at the lower part of the lower cone (730) and is sleeved with the central tube (100); The unsealing ring (003) is located at the lower part of the split claw locking mechanism (002) and is fixedly connected to the central tube (100) by a fixing pin (004); A C-ring (005) is also provided between the unsealing ring (003) and the central tube (100).

7. The packer with reversible setting and unsetting capabilities using hydraulic action according to claim 6, characterized in that: During the setting process, pressure is applied to the central tube (100), and the pressure enters the second cavity (002) through the pressure transmission hole (120). Under the action of the pressure, the connecting sleeve (600) drives the outer sleeve (400) and the starting sleeve (500) to move upward. As the starting sleeve (500) moves upward, it squeezes the limiting ball (910), and the limiter is compressed towards the central tube (100), thus releasing the lock on the starting sleeve (500). As the outer sleeve (400) moves upward, it pushes the lower cone (730) upward, causing the slip (720) to move away from the central tube (100). At the same time, the upper cone (710) squeezes the rubber tube (300), causing the rubber tube (300) to expand under pressure, and the barbed threads inside the outer sleeve (400) lock together with the barbed threads on the split claw locking mechanism (002).

8. The packer with reversible setting and unsetting capabilities using hydraulic action according to claim 7, characterized in that: During unsealing, the pressure applied to the central tube (100) is stopped and the tube column is lifted, causing the unsealing ring (003) to move upward with the central tube (100) and push the split claw locking mechanism (002) to retract into the central tube (100), releasing the lock with the outer sleeve (400); at the same time, the rubber tube (300) and the slip (720) return to their state before setting, and the limiting ball (910) is inserted into the positioning hole (510) of the starting sleeve (500).

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