Slip prevention mechanism and oil casing anchoring system
By using the limiting keyway and short key design of the slip anti-detachment mechanism, the problem of slip detachment and falling into the well during deep well operations is solved, achieving a reliable anti-detachment effect and reducing the risk of connection failure.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SINOPEC OILFIELD SERVICE CORPORATION
- Filing Date
- 2024-12-25
- Publication Date
- 2026-06-26
AI Technical Summary
Existing slip anti-detachment mechanisms are prone to loosening or breakage of connecting screws or fixing pins during deep and ultra-deep well operations, which could lead to slip detachment and the slips falling into the well.
The design employs a short key on the strip-shaped slip and a limiting keyway on the slip cone. The lower end face of the limiting keyway contacts the slip to prevent it from slipping out, simplifying the anti-slip structure and reducing the use of connecting screws or fixing pins.
It effectively prevents the slip cone and strip slip from separating and falling into the well during deep and ultra-deep well operations, reducing the risk of stuck drill bit. It has a simple structure and high reliability.
Smart Images
Figure CN122280467A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the technical field of downhole testing tools for oil and gas, and specifically relates to a slip anti-detachment mechanism and a casing anchoring system. Background Technology
[0002] As oilfield exploration and development progresses to deeper layers, the demand for 5 1 / 2″ small-bore high-temperature and high-pressure mechanical packers is gradually increasing. Conventional oil casing anchoring systems often use screws or fixing pins for slip anti-detachment mechanisms. In deep and ultra-deep applications, there is a risk that the connecting screws or fixing pins may loosen or break, leading to slip detachment or even the well falling into the well and causing the drill bit to get stuck.
[0003] To address the problems and risks associated with such downhole operations, there is an urgent need to develop a new type of slip anti-detachment mechanism. Summary of the Invention
[0004] In view of this, this application proposes a slip anti-detachment mechanism, which solves the problem that existing slip anti-detachment mechanisms using threaded or fixed pin connections are prone to detachment and failure.
[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A slip anti-detachment mechanism includes a slip cone mounted on the central tube of a packer, multiple strip slips, and a slip seat. The outer circumferential surface of the slip cone has multiple sloping grooves near its lower end, each corresponding to one of the strip slips and slidingly engaging with it. A limiting keyway is provided along the axis of symmetry on the bottom plane of each sloping groove. The inner side of the tail of each strip slip has an inclined surface that slides with the bottom plane. A short key is provided on the inclined surface that can slide along the limiting keyway. The head of each strip slip is connected to the slip seat via a dovetail groove. The lower root of the limiting keyway is designed to be a certain distance from the lower end face of the slip cone. When the short key moves to contact the lower inner end face of the limiting keyway, it is limited to prevent the strip slip from slipping out of the inclined groove.
[0006] Furthermore, a radial hole communicating with the inner wall of the slip cone is provided on the bottom surface of the lower root of the limiting keyway.
[0007] Furthermore, the diameter of the radial hole is consistent with the width of the limiting keyway.
[0008] Furthermore, the direction in which the short key moves along the limiting keyway is the first direction, and the direction perpendicular to the first direction on the inclined plane is the second direction. The dimension of the short key extending along the first direction is greater than the dimension of the short key extending along the second direction.
[0009] Furthermore, the dimension of the short key extending along the first direction is 3-3.5 times the dimension of the short key extending along the second direction.
[0010] Furthermore, the short key is projected onto the inclined plane in the shape of a rectangle, and both sides of the lower end face of the short key are provided with rounded corner structures.
[0011] Furthermore, the outer circumference of the slip cone is evenly distributed with multiple oblique grooves that correspond one-to-one with the multiple strip-shaped slips.
[0012] Furthermore, the inclined groove is a T-groove or a dovetail groove.
[0013] Furthermore, the strip-shaped chuck has guide protrusions on both sides of its tail, and the guide protrusions cooperate with the side cavity of the inclined groove.
[0014] The present invention also provides an oil casing anchoring system, including the slip anti-detachment mechanism described in any of the preceding claims.
[0015] Because the short key offers greater flexibility in shape design and fewer size limitations compared to a connecting pin, and because the short key and the strip slip can be integrated, the slip anti-detachment mechanism provided in this embodiment of the invention uses the short key on the strip slip to engage with the lower inner end face of the upper limit keyway of the slip cone for limiting. This eliminates the need for additional limiting screws or fixing pins for axial limiting, reliably preventing the strip slip from detaching along the slip cone's slide rail. This simplifies the anti-detachment structure and reduces the risk of loosening or breaking of connecting screws or fixing pins in deep and ultra-deep applications, which could lead to the slip cone detaching from the strip slip, or even the slip falling into the well and causing stuck drill bit. Therefore, the slip anti-detachment mechanism provided in this embodiment of the invention has the advantages of simple structure and reliable prevention of the slip cone detaching from the strip slip, or even the slip falling into the well and causing stuck drill bit.
[0016] The mechanical packer provided by the present invention includes the aforementioned slip anti-detachment mechanism and has the advantages of the aforementioned slip anti-detachment mechanism, which will not be elaborated here. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 This is a schematic diagram of the initial state of the anti-detachment mechanism provided in a specific embodiment of the present invention.
[0019] Figure 2This is a schematic diagram of the locking mechanism after it has been set in place, according to a specific embodiment of the present invention.
[0020] Figure 3 This is a schematic diagram of the anti-detachment state of the anti-detachment mechanism after unsealing, as provided in a specific embodiment of the present invention.
[0021] Figure 4 This is a side view of a strip-shaped clasp provided in a specific embodiment of the present invention.
[0022] Figure 5 for Figure 4 A schematic diagram of the C-direction structure.
[0023] The following labels are shown in the attached diagram: 1. Slip cone; 11. Inclined groove; 12. Limiting keyway; 121. Limiting surface; 122. Radial hole; 2. Strip slip; 21. Inclined surface; 22. Short key; 23. Guide protrusion; 3. Slip seat; 31. Dovetail groove; 4. Packer center tube. Detailed Implementation
[0024] 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.
[0025] Please refer to Figures 1 to 5 , Figure 1 This is a schematic diagram of the initial state of the slip anti-detachment mechanism provided in a specific embodiment of the present invention; Figure 2 This is a schematic diagram of the locking mechanism after it has been set in place, according to a specific embodiment of the present invention. Figure 3 This is a schematic diagram of the anti-detachment state of the slip mechanism after unsealing, according to a specific embodiment of the present invention. Figure 4 This is a side view of the strip-shaped cladding structure provided in a specific embodiment of the present invention; Figure 5 for Figure 4 A schematic diagram of the C-direction structure.
[0026] This invention provides a slip anti-detachment mechanism comprising a slip cone 1, multiple strip slips 2, and a slip seat 3 mounted on a packer central tube 4. The outer circumferential surface of the slip cone 1 has multiple sloping grooves 11 spaced apart along the circumferential direction near its lower end, each corresponding to one of the multiple strip slips 2. The strip slips 2 and the slip cone 1 form a separate slip assembly. A limiting keyway 12 is provided along the axis of symmetry on the bottom plane of the sloping groove 11. An inclined surface 21, slidingly engaging with the bottom plane, is provided on the inner side of the tail of the strip slip 2. A short key 22, which can slide along the limiting keyway 12, is provided along the axis of the inclined surface 21. Due to the presence of the short key 22, the strip slips 2 cannot be directly assembled during assembly; instead, they can be cold-fitted into the sloping groove 11 of the slip cone 1.
[0027] The head of the strip-shaped slip 2 is connected to the slip seat 3 via a dovetail groove 31. This connection via the dovetail groove 31 is a conventional configuration in the art. When the strip-shaped slip 2 is lifted or pressed down, the upper and lower surfaces of the strip-shaped slip 2 and the dovetail groove 31 come into contact, so that when the strip-shaped slip 2 is lifted, the dovetail groove 31 can restrict the radial position of the head of the strip-shaped slip 2. When the strip-shaped slip 2 is pressed down and spread open, the dovetail groove 31 no longer restricts the radial displacement of the strip-shaped slip 2.
[0028] The lower root of the limiting keyway 12 is designed to be a certain distance from the lower end face of the slip cone 1. The lower inner end face of the limiting keyway 12 can serve as a limiting surface 121. When the short key 22 moves to the point where its lower end face contacts the lower inner end face of the limiting keyway 12, the short key 22 is limited to prevent the strip slip 2 from slipping out of the inclined groove 11. In other words, the lower inner end face of the limiting keyway 12 serves to limit the downward movement of the strip slip 2 and prevent it from slipping out. The strength design of the short key 22 and the limiting surface at the root of the limiting keyway 12 is verified through comprehensive stress simulation to meet the stress requirements of the slip under various working conditions without failure.
[0029] In use, when axial displacement is applied to the slip cone 1, the strip slip 2 opens (when the slip cone 1 moves downward) or contracts (when the slip cone 1 moves upward) along the inclined surface 21 at the lower end of the slip cone 1. When the slip cone 1 moves upward to the point where the lower inner end face of the limiting keyway 12 contacts and limits the contact with the end face of the short key 22 on the strip slip 2, the strip slip 2 moves upward synchronously with the slip cone 1, thereby preventing the strip slip 2 from detaching from the slip cone 1.
[0030] Because the shape of the short key 22 is more flexible and its size is less restricted compared to the connecting pin, and the short key 22 and the strip slip 2 can be integrated, the slip anti-detachment mechanism provided in this embodiment of the invention uses the short key 22 on the strip slip 2 to cooperate with the lower inner end face of the upper limit keyway 12 of the slip cone 1 for limiting. No additional limiting screw or fixing pin is required for axial limiting, which can reliably prevent the strip slip 2 from detaching along the slide of the slip cone 1. This simplifies the anti-detachment structure and reduces the risk of loosening or breaking of the connecting screw or fixing pin in deep and ultra-deep applications, which could lead to the slip cone 1 detaching from the strip slip 2 or even falling into the well and causing the drill bit to get stuck.
[0031] Therefore, the slip anti-detachment mechanism provided in this embodiment of the invention has the advantages of simple structure and reliable ability to prevent slip cone 1 from detaching from strip slip 2, or even falling into the well and causing the drill bit to get stuck.
[0032] In some embodiments, preferably, a radial hole 122 communicating with the inner wall of the slip cone 1 is provided on the bottom surface of the lower root of the limiting keyway 12. The beneficial effect of this arrangement is that when the tool is used in the well, foreign objects such as mud and sand can flow normally in the limiting keyway 12, preventing their deposition in the limiting keyway 12, which would cause the strip slip 2 to be obstructed from moving and unable to be fully reset when unsealed, thus affecting the unsealing of the tool.
[0033] Based on the above embodiments, the diameter of the radial hole 122 is made to match the width of the limiting keyway 12, which can reliably prevent foreign objects such as mud and sand from depositing in the limiting keyway 12 when the tool is used in the well. In addition, the central axis of the radial hole 122 is perpendicular to the bottom surface of the lower root of the limiting keyway 12, which facilitates machining.
[0034] In some embodiments, the direction in which the short key 22 moves along the limiting keyway 12 is a first direction, and the direction perpendicular to the first direction on the inclined surface 21 is a second direction. The dimension of the short key 22 extending along the first direction is greater than the dimension of the short key 22 extending along the second direction. For ease of understanding, the attached diagram is used. Figure 5 The arrow A in the diagram indicates the first direction, indicated by the appendix. Figure 5 The arrow B in the diagram indicates the second direction, which makes the dimension of the short key 22 extending along the first direction greater than the dimension of the short key 22 extending along the second direction. This allows the short key 22 to have a larger dimension in the direction of shear force, thus preventing damage to the short key 22 and increasing the service life of the strip-shaped slip 2. This also more reliably prevents the strip-shaped slip 2 from detaching from the slip cone 1, and on the other hand, it can also reduce sliding resistance.
[0035] Based on the above embodiments, specifically, the dimension of the short key 22 extending in the first direction is 3-3.5 times the dimension of the short key 22 extending in the second direction, thereby increasing the service life of the strip slip 2 and avoiding the short key 22 affecting the sliding stroke of the strip slip 2.
[0036] like Figure 5 As shown, based on the above embodiment, the short key 22 is projected onto the inclined plane 21 in a rectangular shape, and both sides of the lower end face of the short key 22 are provided with rounded corner structures. Setting the short key 22 as a rectangle facilitates that the dimension of the short key 22 extending in the first direction is greater than the dimension of the short key 22 extending in the second direction. The rounded corner structures on both sides of the lower end face of the short key 22 allow for smoother sliding of the short key 22 within the limiting keyway 12, and also prevent stress concentration at the corners of the short key 22, thus avoiding fatigue damage.
[0037] In some embodiments, the outer circumference of the slip cone 1 is evenly distributed with multiple inclined grooves 11 that correspond one-to-one with multiple strip slips 2. After setting, the evenly distributed inclined grooves 11 can make the slip cone 1 receive a balanced reaction force from multiple strip slips 2, which is beneficial to maintaining the stability of the anchoring system.
[0038] In some embodiments, the inclined groove 11 is a T-groove or a dovetail groove. T-groove or dovetail grooves are standard and commonly used groove shapes that are easy to process.
[0039] Based on the above embodiment, guide protrusions 23 are provided on both sides of the tail of the strip-shaped slip 2. The guide protrusions 23 cooperate with the side cavity of the inclined groove 11 to limit the displacement of the guide strip-shaped slip 2.
[0040] Embodiments of the present invention also provide an oil casing anchoring system, including the slip anti-detachment mechanism described above.
[0041] The casing anchoring system provided in the embodiments of the present invention has the advantages of the aforementioned slip anti-detachment mechanism, which will not be elaborated here.
[0042] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.
[0043] The automatic roller mechanism for the drilling tool provided by this invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this invention. Therefore, this invention is not limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A slip anti-detachment mechanism, comprising a slip cone (1) mounted on the central tube (4) of a packer, a plurality of strip slips (2) and slip seats (3), characterized in that, The outer circular surface of the slip cone (1) near the lower end is provided with a plurality of inclined grooves (11) that are slidably engaged with the plurality of strip slips (2) in a circumferential direction. A limiting keyway (12) is provided on the bottom plane of the inclined groove (11) along the axis of symmetry. The inner side of the tail of the strip slip (2) is provided with an inclined surface (21) that is slidably engaged with the bottom plane. A short key (22) that can slide along the limiting keyway (12) is provided on the inclined surface (21). The head of the strip slip (2) is connected to the slip seat (3) through a dovetail slide groove (31). The lower root of the limiting keyway (12) is designed to be a certain distance from the lower end face of the slip cone (1). When the short key (22) moves to contact the lower inner end face of the limiting keyway (12), it is limited to prevent the strip slip (2) from slipping out of the inclined groove (11).
2. The anti-detachment mechanism for the slip as described in claim 1, characterized in that, The lower root of the limiting keyway (12) is provided with a radial hole (122) that communicates with the inner wall of the locating cone (1).
3. The anti-detachment mechanism for the slip as described in claim 2, characterized in that, The diameter of the radial hole (122) is the same as the width of the limiting keyway (12).
4. The anti-detachment mechanism for the slip as described in claim 1, characterized in that, The direction in which the short key (22) moves along the limiting keyway (12) is the first direction, and the direction perpendicular to the first direction on the inclined surface (21) is the second direction. The dimension of the short key (22) extending along the first direction is greater than the dimension of the short key (22) extending along the second direction.
5. The anti-detachment mechanism for the slip as described in claim 4, characterized in that, The dimension of the short key (22) extending along the first direction is 3-3.5 times the dimension of the short key (22) extending along the second direction.
6. The anti-detachment mechanism for the slip as described in claim 1, characterized in that, The short key (22) is projected onto the inclined plane (21) in the shape of a rectangle, and both sides of the lower end face of the short key (22) are provided with rounded corner structures.
7. The anti-detachment mechanism for the slip mechanism according to claim 1, characterized in that, The outer surface of the slip cone (1) near the lower end has a plurality of oblique grooves (11) that correspond one-to-one with the plurality of strip slips (2).
8. The anti-detachment mechanism for the slip mechanism according to claim 7, characterized in that, The inclined groove (11) is a T-shaped groove or a dovetail groove.
9. The anti-detachment mechanism for the slip mechanism according to claim 8, characterized in that, The strip-shaped chuck (2) has guide protrusions (23) on both sides of its tail, and the guide protrusions (23) cooperate with the side cavity of the inclined groove (11).
10. A casing anchoring system, characterized in that, Includes the anti-detachment mechanism according to any one of claims 1-9.