A type of cementing anchor
The rotating connection design of the connecting rod and the push sleeve improves the tensile strength of the cementing anchor, solves the problem of breakage at the connection between the anchor claw and the main body, adapts to prestressed cementing in small wellbores, and improves the service life and safety of the casing.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SLOF KANGBEI IND & TRADING
- Filing Date
- 2025-07-21
- Publication Date
- 2026-07-03
AI Technical Summary
Existing cementing anchors are prone to breakage at the connection between the anchor claw and the main body due to overload during the anchoring process, resulting in casing damage, and are difficult to adapt to the prestressed cementing requirements of small wellbores.
A cementing anchor was designed, which is connected to the push sleeve by a rotating connection. The push sleeve abuts against the anchor claw. The outer cylinder, the anchor claw seat and the groove jointly bear the anchoring tension. The connecting rod and the push sleeve are almost not subjected to tension at the rotating connection, which prevents breakage. The tensile strength is further improved by the threaded connection between the anti-reverse ring and the push sleeve.
It improves the tensile strength of cementing anchors, prevents breakage at rotating joints, and adapts to the prestressed cementing requirements of small wellbores. Its compact structure avoids excessive opening of the anchor claws, which can jam the well wall.
Smart Images
Figure CN224452745U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of cementing tool technology, specifically, it relates to a cementing anchor. Background Technology
[0002] In oilfield development, steam injection is a common method to enhance oil recovery. However, high-temperature steam also causes axial stress in the downhole casing due to thermal expansion, which can lead to casing deformation and damage in severe cases. To avoid these drawbacks, prestressed cementing technology is widely used. By applying prestress between the formation and the casing, it counteracts the thermal expansion stress of the casing during steam injection, extending casing life. The ground anchor is the core tool for prestressed cementing, effectively transferring prestress by anchoring the casing to the formation. Existing cementing ground anchors typically connect the anchor claws to the main body via pins. After anchoring, the tensile force is usually concentrated on the pin, causing it to break due to fatigue or overload. Utility Model Content
[0003] One objective of this invention is to provide a cementing anchor that allows the push sleeve, anchor claw seat, and outer cylinder to bear the anchoring tension of the anchor claw as a whole, while the connecting rod and push sleeve, the connecting rod and anchor claw, and the anchor claw and anchor claw seat are almost free from tension at the rotating connection points, thus preventing the aforementioned rotating connection points from breaking due to overload and improving tensile strength.
[0004] According to this utility model, a cementing anchor is provided, comprising: a connecting rod, an outer cylinder with multiple slots along the circumference, an anchor claw seat disposed in the slots, an anchor claw rotatably connected to the anchor claw seat, and a push sleeve disposed inside the outer cylinder and movable along the axial direction of the outer cylinder. The first end of the connecting rod is rotatably connected to the push sleeve, and the second end is rotatably connected to the anchor claw. The push sleeve can move toward the anchor claw seat such that: the end of the push sleeve near the anchor claw seat abuts against the first side of the anchor claw, and the second side of the anchor claw abuts against the slots.
[0005] In a preferred embodiment, the inner wall of the outer cylinder is provided with an annular groove, and an anti-retraction ring is provided inside the annular groove. The push sleeve is provided with an anti-retraction thread on the outer surface of the anti-retraction ring located away from the anchor claw seat, which cooperates with the inner wall of the anti-retraction ring.
[0006] In a preferred embodiment, the anchor claw is constructed as an arc-shaped plate, with its first end rotatably connected to the anchor claw seat via a first pin, and its second end having serrated anti-slip texture.
[0007] In a preferred embodiment, the second end of the connecting rod is rotatably connected to the middle of the anchor claw via a second pin.
[0008] In a preferred embodiment, the first end of the connecting rod is rotatably connected to the push sleeve via a third pin.
[0009] In a preferred embodiment, the cementing anchor further includes: a guide head whose first end is connected to the end of the outer cylinder, the first end of the guide head being disposed inside the outer cylinder and connected to the outer cylinder, and the end face of the second end of the guide head being constructed as an arc surface.
[0010] In a preferred embodiment, the anchor claw seat is fixedly connected to the end face of the first end of the guide head.
[0011] In a preferred embodiment, the outer cylinder is provided with four slots evenly distributed along the circumference.
[0012] In a preferred embodiment, the distance between the end of the push sleeve near the anchor claw seat and the anchor claw seat is less than or equal to 60 mm.
[0013] In a preferred embodiment, the outer diameter of the outer cylinder is less than or equal to 127 mm, and when the push sleeve abuts against the first side of the anchor claw and the second side of the anchor claw abuts against the slot, the outer diameter of the cementing anchor is less than or equal to 245 mm.
[0014] This utility model has at least the following technical effects:
[0015] According to this invention, since the first end of the connecting rod is rotatably connected to the push sleeve and the second end is rotatably connected to the anchor claw, the push sleeve moves towards the anchor claw seat such that the end of the push sleeve near the anchor claw seat abuts against the first side of the anchor claw, and the second side of the anchor claw abuts against the groove. Thus, the push sleeve, the anchor claw seat, and the groove exert a coordinated force on the anchor claw seat, allowing the push sleeve, the anchor claw seat, and the outer cylinder as a whole to bear the anchoring tension of the anchor claw. Furthermore, the connecting rod and push sleeve, the connecting rod and the anchor claw, and the anchor claw and anchor claw seat experience almost no tension at the rotatable connections, preventing breakage due to overload and improving tensile strength. In addition, it also prevents the anchor claw from jamming the well wall due to excessive opening.
[0016] According to this utility model, the push sleeve moves toward the direction close to the anchor claw seat until: the end of the push sleeve near the anchor claw seat abuts against the first side of the anchor claw, and the second side of the anchor claw abuts against the groove. The anchor claw is opened to its limit position. Since the inner wall of the anti-retraction ring is threadedly connected to the outer wall of the push sleeve, the tensile force on the anchor claw is transmitted to the anti-retraction ring. The tensile force is jointly borne by the push sleeve, the anchor claw seat, the outer cylinder, and the threads between the inner wall of the anti-retraction ring and the outer wall of the push sleeve, thereby further improving the tensile strength of the cementing anchor. Attached Figure Description
[0017] Figure 1A schematic diagram of the overall structure of a cementing anchor according to an embodiment of the present invention is shown, wherein the anchor claw of the cementing anchor is located inside the groove.
[0018] Figure 2 A schematic diagram of another overall structure of a cementing anchor according to an embodiment of the present invention is shown, wherein the anchor claws of the cementing anchor are in an open state;
[0019] Figure 3 A schematic diagram of the overall structure of the slot of a cementing anchor according to an embodiment of the present invention is shown.
[0020] In this application, all the accompanying drawings are schematic drawings, used only to illustrate the principle of the present invention, and are not drawn to scale. Detailed Implementation
[0021] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.
[0022] In the description of the utility model, it should be understood that the terms "inner" and "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the utility model.
[0023] In this utility model, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection 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.
[0024] like Figures 1 to 3As shown, the cementing anchor 100 of this utility model includes: an outer cylinder b with multiple slots 11 circumferentially arranged, a push sleeve a disposed inside the outer cylinder b and capable of moving axially along the outer cylinder b, a connecting rod 7, an anchor claw seat 9 disposed in the slots 11, and an anchor claw 8 rotatably connected to the anchor claw seat 9. The first end of the connecting rod 7 is rotatably connected to the push sleeve a, and the second end is rotatably connected to the anchor claw 8. In the initial state, the push sleeve a is stationary, and both the connecting rod 7 and the anchor claw 8 are inside the slots 11. When anchoring is required, the push sleeve a is driven to move towards the anchor claw seat 9 inside the outer cylinder b by pressing the rubber plug (not shown in the figure). The connecting rod 7 rotates and extends out of the slot 11, thereby driving the anchor claw 8 to extend out of the slot 11. When the end of the push sleeve a near the anchor claw seat 9 abuts against the first side of the anchor claw 8, and the second side of the anchor claw 8 abuts against the slot 11, the teeth on the top of the anchor claw 8 are in close contact with the stratum, thus completing the anchoring. At this time, the connecting rod 7 and the push sleeve a, the connecting rod 7 and the anchor claw 8, and the anchor claw 8 and the anchor claw seat 9 are not under tension at the rotational connection.
[0025] According to this utility model, since the first end of the connecting rod 7 is rotatably connected to the push sleeve a and the second end is rotatably connected to the anchor claw 8, the push sleeve a moves towards the anchor claw seat 9 such that the end of the push sleeve a near the anchor claw seat abuts against the first side of the anchor claw 8, and the second side of the anchor claw 8 abuts against the groove 11. Thus, the push sleeve a, the anchor claw seat 9, and the groove 11 exert a coordinated force on the anchor claw seat 9, causing the push sleeve a, the anchor claw seat 9, and the outer cylinder b to bear the anchoring tension of the anchor claw 8 as a whole. Furthermore, the connecting rod 7 and the push sleeve a, the connecting rod 7 and the anchor claw 8, and the anchor claw 8 and the anchor claw seat 9 are almost free from tension at the rotatable connections, preventing breakage due to overload at these rotatable connections and improving tensile strength. In addition, the cementing anchor 100 described in this utility model can also prevent the anchor claw 8 from jamming the well wall due to excessive opening.
[0026] In one or more embodiments, the outer diameter of the outer cylinder b is ≤127mm. When the end of the push sleeve a near the anchor claw seat 9 abuts against the first side of the anchor claw 8 and the second side of the anchor claw 8 abuts against the slot 11, the outer diameter of the cementing anchor 100 is less than or equal to 245mm. The structure is compact, thus it can be adapted to small-sized wellbores and meet the prestressed cementing requirements of small wellbores.
[0027] In one or more embodiments, an annular groove is formed on the inner wall of the outer cylinder b, and an anti-retraction ring 3 is disposed inside the annular groove. The outer wall of the anti-retraction ring 3 contacts the annular groove, and the push sleeve a has an anti-retraction thread on the outer surface of the anti-retraction ring 3 on the side away from the anchor claw seat 9, which mates with the inner wall of the anti-retraction ring 3. When the push sleeve a moves inside the outer cylinder b toward the anchor claw seat 9 such that the end of the push sleeve a near the anchor claw seat 9 abuts against the first side of the anchor claw 8, and the second side of the anchor claw 8 abuts against the groove 11, the inner wall of the anti-retraction ring 3 is threadedly connected to the outer wall of the push sleeve a.
[0028] According to this utility model, the push sleeve a moves toward the direction close to the anchor claw seat 9 until: the end of the push sleeve a near the anchor claw seat abuts against the first side of the anchor claw 8, and the second side of the anchor claw 8 abuts against the groove 11. The anchor claw 8 opens to its limit position. Since the inner wall of the anti-retraction ring 3 is threadedly connected to the outer wall of the push sleeve a, the tension on the anchor claw 8 is transmitted to the anti-retraction ring 3. The tension is jointly borne by the push sleeve a, the anchor claw seat 9, the outer cylinder b, and the threads between the inner wall of the anti-retraction ring 3 and the outer wall of the push sleeve a, thereby further improving the tensile strength of the cementing anchor 100.
[0029] In one or more embodiments, the anchor claw 8 is constructed as an arc-shaped plate, and the first end of the anchor claw 8 is rotatably connected to the anchor claw seat 9 via a first pin 12, and its second end is provided with serrated anti-slip texture.
[0030] In one or more embodiments, the second end of the connecting rod 7 is rotatably connected to the middle of the anchor claw 8 via the second pin 13, so that when the push sleeve a moves inside the outer cylinder b toward the direction of the anchor claw seat 9, the connecting rod 7 pushes the anchor claw 8 to rotate unidirectionally around the anchor claw seat 9, that is, it can only open outward from the slot 11.
[0031] In one or more embodiments, the first end of the connecting rod 7 is rotatably connected to the push sleeve a via a third pin 14.
[0032] In one or more embodiments, the cementing anchor 100 of the present invention further includes: a guide head 10 whose first end is connected to the end of the outer cylinder b, the first end of the guide head 10 being disposed inside the outer cylinder b and fixedly connected to the outer cylinder b by a thread, the end face of the second end of the guide head 10 being constructed as an arc surface for guiding, the first end of the central shaft c passing through the second end of the guide head 10 into the guide head 10, and its second end passing through the end of the push sleeve a near the anchor claw seat 9.
[0033] In one or more embodiments, the anchor claw seat 9 is fixedly connected to the end face of the first end of the guide head 10.
[0034] In one or more embodiments, the outer cylinder a is constructed as a hollow cylinder, including: an upper outer cylinder 1 and a lower outer cylinder 4 threadedly connected to the upper outer cylinder 1, wherein the lower outer cylinder 4 has a plurality of slots 11 circumferentially formed. The push sleeve a includes: an upper push sleeve 2 and a lower push sleeve 5 threadedly connected to the upper push sleeve 2, wherein the first end of the connecting rod 7 is rotatably connected to the lower push sleeve 5.
[0035] In one or more embodiments, the outer cylinder b has four slots 11 evenly distributed along its circumference. Each slot 11 contains an anchor claw seat 9 and an anchor claw 8 rotatably connected to the anchor claw seat 9. This utility model adopts a design with four evenly distributed anchor claws 8, and with the serrated anti-slip texture on the top of the anchor claw 8, it can increase the contact area and friction with the stratum, making it less prone to slippage after anchoring.
[0036] In one or more embodiments, the distance between the end of the push sleeve a near the anchor claw seat 9 and the anchor claw seat 9 is less than or equal to 60 mm, and the overall stroke of the push sleeve a is short, thereby avoiding accidental closure of the anchor claw 8 due to downhole working condition interference.
[0037] Although the present invention has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.
Claims
1. A cementing earth anchor characterized by, include: The system comprises a connecting rod, an outer cylinder with multiple slots along its circumference, an anchor claw seat disposed within the slots, an anchor claw rotatably connected to the anchor claw seat, and a push sleeve disposed inside the outer cylinder and movable along the axial direction of the outer cylinder. The first end of the connecting rod is rotatably connected to the push sleeve, and the second end is rotatably connected to the anchor claw. The push sleeve is movable toward the anchor claw seat such that the end of the push sleeve near the anchor claw seat abuts against the first side of the anchor claw, and the second side of the anchor claw abuts against the slot.
2. The cemented ground anchor of claim 1, wherein, The inner wall of the outer cylinder is provided with an annular groove, and an anti-retraction ring is provided inside the annular groove. The push sleeve is provided with an anti-retraction thread on the outer surface of the anti-retraction ring located away from the anchor claw seat, which cooperates with the inner wall of the anti-retraction ring.
3. The cemented-in ground anchor according to claim 1 or 2, characterized in that The anchor claw is constructed as an arc-shaped plate, and its first end is rotatably connected to the anchor claw seat through a first pin, while the second end is provided with serrated anti-slip texture.
4. The cemented-in ground anchor according to claim 3, characterized in that The second end of the connecting rod is rotatably connected to the middle part of the anchor claw via a second pin.
5. The cemented ground anchor of claim 4, wherein, The first end of the connecting rod is rotatably connected to the push sleeve via a third pin.
6. The cemented-in ground anchor according to claim 1 or 2, characterized in that Also includes: A guide head is connected to the end of the outer cylinder at its first end. The first end of the guide head is located inside the outer cylinder and connected to the outer cylinder. The end face of the second end of the guide head is constructed as an arc surface.
7. The cemented ground anchor of claim 6, wherein, The anchor claw seat is fixedly connected to the end face of the first end of the guide head.
8. The cemented-in ground anchor according to claim 1 or 2, characterized in that The outer cylinder has four slots evenly distributed around its circumference.
9. The cemented-in ground anchor according to claim 1 or 2, characterized in that The distance between the end of the push sleeve near the anchor claw seat and the anchor claw seat is less than or equal to 60 mm.
10. The cemented ground anchor of claim 9, wherein, The outer diameter of the outer cylinder is less than or equal to 127 mm. When the push sleeve abuts against the first side of the anchor claw and the second side of the anchor claw abuts against the slot, the outer diameter of the cementing anchor is less than or equal to 245 mm.