Fossette fish spear
By designing a shallow-hole fish-retrieval spear and using slip components to tighten the fish, the problem of existing tools being unable to retrieve fish from shallow holes was solved, achieving efficient and reliable retrieval results and protecting the wellbore.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- PETROCHINA CO LTD
- Filing Date
- 2024-12-03
- Publication Date
- 2026-06-05
AI Technical Summary
Existing fishing tools are ineffective at retrieving fish that have fallen into shallow spots inside the tubing, resulting in high production costs, damage to the tubing string, and reduced wellbore life.
A shallow-water fish-catching spear was designed, comprising an outer cylinder, a core shaft, a slip seat, and a slip assembly. By cutting the shear pin, the slip seat moves downward, driving the slip assembly downward along the tapered tube section. The slip assembly expands outward to trap the fish, thus completing the catching operation.
It achieves stable, reliable, and efficient retrieval of fish that have fallen into shallow wells, avoiding the high-cost methods of retrieving tubing or milling, and protecting the integrity of the wellbore.
Smart Images
Figure CN122148215A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of fishing tools, specifically a spear for catching fish that have fallen into shallow waters. Background Technology
[0002] In oil and gas well engineering in the petroleum industry, it is common to encounter operations involving the use of a retrieval spear to retrieve downhole tools. This involves transporting the retrieval spear downhole and retrieving the tools that have fallen into the well. When transporting the retrieval spear, wire rope or drill pipe, tubing, and sucker pipe are generally used. The retrieval spear is transported by wire rope and moves down to the predetermined position under its own weight.
[0003] Currently, when encountering a fish that has fallen into the tubing with its outer diameter close to the inner wall, and a small hole in the middle with only a shallow depression about 30 mm in diameter and 30 mm in depth at the top, the adhesion between the fish and the tubing is relatively strong, so the only part that can be grabbed is the shallow depression about 30 mm in diameter. Existing retrieval tools cannot retrieve fish that have fallen into such shallow depressions. Therefore, the only methods are to lift out the tubing string to retrieve the fish or to use milling to grind the fish into fragments. However, both of these methods are not only costly, but also damage the tubing string and affect the life of the wellbore. Summary of the Invention
[0004] This invention provides a spear for catching fish in shallow waters, which overcomes the shortcomings of the prior art and can effectively solve the problem that existing catching tools cannot catch fish in shallow waters.
[0005] The technical solution of this invention is achieved through the following measures: A shallow-water fish-catching spear includes an outer cylinder, a spindle, a slip seat, and a slip assembly. The lower side of the outer cylinder has an upward-opening mounting hole. Corresponding to the upper part of the mounting hole, the outer side of the outer cylinder has several balance holes that communicate with the mounting hole. The spindle has a vertically penetrating flow channel in its middle section. The spindle includes a large-diameter section, a small-diameter section, and a tapered tube section. The large-diameter section is located within the mounting hole below the balance holes, and the lower end of the large-diameter section has a small-diameter section located below the outer cylinder. The section has a tapered tube section at the lower end of the small-diameter section, which is shaped like a frustum with a smaller upper diameter and a larger lower diameter. The outer side of the middle part of the large-diameter section has several sliding holes, which are oblong holes. The outer side of the outer cylinder corresponding to the upper end of each sliding hole is provided with a sliding screw whose inner end is located in the sliding hole. The upper outer side of the small-diameter section is fixedly installed with a slip seat by a shear pin. The lower inner side of the slip seat is provided with an installation ring groove. The slip assembly with its lower end located on the outer side of the upper end of the tapered tube section is limited and installed in the installation ring groove. The lower inner side of the slip assembly is provided with a tapered hole that matches the tapered tube section.
[0006] The following are further optimizations and / or improvements to the above-mentioned technical solution: The aforementioned slip assembly may include a slip cylinder and a pressure cap. The upper outer side of the slip cylinder is provided with a limiting ring platform located in the limiting ring groove. The lower outer side of the slip cylinder is provided with several annular retrieval teeth spaced vertically. The slip cylinder includes at least two separately arranged slip pieces. The lower outer side of the slip seat is fixedly installed with a pressure cap located below it. The lower inner side of the pressure cap is provided with an installation ring platform. The lower end of the limiting ring platform sits on the upper side of the installation ring platform.
[0007] The aforementioned slip assembly may also include set screws. A pressure cap with its lower end located below it is fixedly installed on the outer side of the lower end of the slip seat via a threaded connection. At least two set screws are provided at circumferential intervals on the outer side of the upper part of the pressure cap to fix the pressure cap and the slip seat together.
[0008] The aforementioned slip assembly may also include a clamping ring, with an upper clamping ring groove on the outer side of the middle of the limiting ring platform, and a lower clamping ring groove on the outer side of the slip cylinder corresponding to the position between the pressure cap and the annular retrieval tooth. Both the upper and lower clamping ring grooves are equipped with clamping rings.
[0009] The outer upper part of the outer cylinder and the outer upper part of the large diameter section can both be provided with retrieval ring grooves.
[0010] The outer cylinder has four balancing holes evenly distributed around its circumference on the upper outer side, four sliding holes evenly distributed around its circumference on the middle outer side of the large diameter section, and four shear pins evenly distributed around its circumference on the upper outer side of the small diameter section.
[0011] The above may also include a rope cap, a weight bar, and a shock absorber, which are installed together from top to bottom by threaded connections.
[0012] This invention has a reasonable and compact structure and is easy to use. By cutting the shear pin, the slip seat moves downward under the action of the outer cylinder, and drives the slip assembly downward along the conical tube section. The inner side of the lower end of the slip assembly expands outward under the action of the conical tube section to catch the fish, thereby completing the fish retrieval operation in shallow water. It has the characteristics of stability, reliability and high efficiency. Attached Figure Description
[0013] Appendix Figure 1 These are schematic diagrams of the main cross-sectional structure of embodiments 1 to 6 of the present invention.
[0014] Appendix Figure 2 This is a schematic diagram of the front sectional view of Embodiment 7 of the present invention.
[0015] The codes in the attached diagram are as follows: 1 for outer cylinder, 2 for large diameter section, 3 for small diameter section, 4 for tapered tube section, 5 for slip seat, 6 for pressure cap, 7 for slip plate, 8 for annular retrieval tooth, 9 for clamping ring, 10 for balance hole, 11 for flow channel, 12 for mounting hole, 13 for sliding hole, 14 for mounting ring groove, 15 for limiting ring platform, 16 for mounting ring platform, 17 for retrieval ring groove, 18 for sliding screw, 19 for shearing pin, 20 for set screw, 21 for rope cap, 22 for weighting rod, 23 for shock absorber, and 24 for fish dropper. Detailed Implementation
[0016] The present invention is not limited to the following embodiments, and the specific implementation can be determined according to the technical solution of the present invention and the actual situation.
[0017] In this invention, for ease of description, the description of the relative positions of the components is based on the appendix to the specification. Figure 1 The layout is described using a diagrammatic method, such as front, back, top, bottom, left, right, etc. The positional relationships are determined based on the layout direction of the attached diagram in the instruction manual.
[0018] The present invention will be further described below with reference to embodiments and accompanying drawings: Example 1: As shown in the attached document Figure 1 , 2 As shown, the shallow-water fish-catching spear 24 includes an outer cylinder 1, a spindle, a slip seat 5, and a slip assembly. The lower side of the outer cylinder 1 has an upward-opening mounting hole 12. Corresponding to the upper part of the mounting hole 12, the outer side of the outer cylinder 1 has several balance holes 10 that communicate with the mounting hole 12. The spindle has a vertically penetrating flow channel 11 in its middle. The spindle includes a large-diameter section 2, a small-diameter section 3, and a tapered tube section 4. The large-diameter section 2 is located inside the mounting hole 12 below the balance holes 10. The lower end of the large-diameter section 2 has a small-diameter section 3 located below the outer cylinder 1. The lower end of the small-diameter section 3... A tapered tube section 4 is provided, which is shaped like a frustum with a smaller upper diameter and a larger lower diameter. Several sliding holes 13 are provided on the outer side of the middle part of the large diameter section 2. The sliding holes 13 are oblong holes. A sliding screw 18 with its inner end located in the sliding hole 13 is provided on the outer side of the outer cylinder 1 corresponding to the upper end of each sliding hole 13. A slip seat 5 is fixedly installed on the outer side of the upper part of the small diameter section 3 by a shear pin 19. A mounting ring groove 14 is provided on the inner side of the lower end of the slip seat 5. A slip assembly with its lower end located on the outer side of the upper end of the tapered tube section 4 is limited and installed in the mounting ring groove 14. A tapered hole matching the tapered tube section 4 is provided on the inner side of the lower end of the slip assembly. During use, the existing rope cap 21, weight bar 22 and shocker 23 are installed sequentially from top to bottom on the outer side of the upper end of this embodiment, and corresponding anti-loosening measures are taken at the connecting threads. By cutting the shear pin 19, the slip seat 5 moves downward under the action of the outer cylinder, and drives the slip assembly to move downward along the tapered tube section 4. The inner side of the lower end of the slip assembly expands outward and tightens the fish 24 under the action of the tapered tube section 4, thereby completing the retrieval operation of the shallow fish 24.
[0019] The above-mentioned shallow-water fish-catching spear 24 can be further optimized and / or improved according to actual needs: Example 2: As shown in the attached document Figure 1 , 2 As shown, the slip assembly includes a slip cylinder and a pressure cap 6. The upper outer side of the slip cylinder has a limiting ring platform 15 located within a limiting ring groove. The lower outer side of the slip cylinder has several annular retrieval teeth 8 spaced vertically. The slip cylinder includes at least two separately configured slip pieces 7. A pressure cap 6 with its lower end located below it is fixedly installed on the lower outer side of the slip base 5. An installation ring platform 16 is provided on the lower inner side of the pressure cap 6, and the lower end of the limiting ring platform 15 sits on the upper side of the installation ring platform 16. During use, the pressure cap 6 facilitates the limiting installation of the slip cylinder within the slip base 5; the annular retrieval teeth 8 facilitate the slip gripping the fish 24; and the separately configured slip pieces 7 facilitate the tightening of the fish 24.
[0020] Example 3: As shown in the attached document Figure 1 , 2 As shown, the locking assembly also includes set screws 20. A pressure cap 6, with its lower end located below it, is fixedly installed on the lower outer side of the locking seat 5 via a threaded connection. At least two set screws 20 are spaced circumferentially on the upper outer side of the pressure cap 6 to securely install the pressure cap 6 and the locking seat 5 together. During use, the set screws 20 effectively prevent loosening between the threaded locking seat 5 and the pressure cap 6.
[0021] Example 4: As shown in the appendix Figure 1 , 2 As shown, the slip assembly also includes clamping rings 9. An upper clamping ring groove is provided on the outer side of the middle of the limiting ring platform 15, and a lower clamping ring groove is provided on the outer side of the slip cylinder corresponding to the position between the pressure cap 6 and the annular retrieval tooth 8. Clamping rings 9 are provided in both the upper and lower clamping ring grooves. During use, by setting two clamping rings 9 spaced apart vertically, the four separately arranged slip pieces 7 are clamped, thereby ensuring that the slip pieces 7 are tightly attached to the outer side of the mandrel, thus enhancing the stability during the retrieval process in this embodiment.
[0022] Example 5: As shown in the attached document Figure 1 , 2 As shown, both the outer upper outer side of the outer cylinder 1 and the outer upper outer side of the large-diameter section 2 are provided with retrieval annular grooves 17. This design enhances the stability of the retrieval process in this embodiment during use.
[0023] Example 6: As attached Figure 1 , 2As shown, four balancing holes 10 are evenly distributed around the circumference on the upper outer side of the outer cylinder 1, four sliding holes 13 are evenly distributed around the circumference on the middle outer side of the large-diameter section 2, and four shear pins 19 are evenly distributed around the circumference on the upper outer side of the small-diameter section 3. This arrangement enhances the stability of the salvage process in this embodiment during use.
[0024] Example 7: As attached Figure 1 , 2 As shown, it also includes a rope cap 21, a weight bar 22, and a shock absorber 23. The rope cap 21, the weight bar 22, the shock absorber 23, and the outer cylinder 1 are sequentially fixed together by threaded connection from top to bottom.
[0025] During use, when retrieving fish 24 from shallow spots on-site, the existing rope cap 21, weight bar 22, and shocker 23 are installed sequentially from top to bottom on the outer side of the upper part of this embodiment, and corresponding anti-loosening measures are taken at the connecting threads. The shocker 23 can be a chain shocker 23. Before the retrieval operation, the specific location of the fish 24 should be accurately measured, and a lead mold should be used to confirm that the shallow spot of the fish 24 is not blocked by other debris. Otherwise, it should be cleaned. After everything is ready, the tool string should be slowly lowered in according to the wire rope operation procedure. When approaching the fish-dropping point 24, control the descent speed of the tool string to below 1 meter / minute. Closely observe the suspended weight of the tool string. When the suspended weight begins to decrease, it indicates that the end of the retrieval tool has contacted the fish-dropping point 24. Continue to descend slowly. At this point, the weight of the retrieval tool and the lower half of the chain shocker 23 is borne by the fish-dropping point 24, and the suspended weight remains almost unchanged. When the suspended weight decreases again, it indicates that the upper and lower parts of the chain shocker 23 have come together. Immediately stop lowering and slowly raise the tool string. The raising distance should be 200mm less than the stroke of the chain shocker 23. Note the raising position and release quickly. The weight rod 22 and the chain shocker 23 apply an impact force to the outer cylinder 1. Using the outer cylinder 1, push the slip seat 5 to cut the shearing pin 19, forcing the slip 7 to move down and simultaneously expanding outwards to tighten the fish 24 under the action of the cone tube section 4. To ensure that the fish 24 is reliably caught, it can be raised to the recorded position and released quickly a total of 3 times. Then, slowly raise the tool string and observe the suspended weight. If the suspended weight increases significantly, it means that the fish 24 has been caught. At this time, the tool string can be lowered again. After observing that the suspended weight decreases, quickly raise it and scoop out the fish 24 by shaking it upwards. After shaking it, raise the tool string. If the suspended weight does not increase significantly, it means that the fish 24 has been scooped out. The tool string can be raised at a constant speed according to the operating procedure to complete the fish 24 retrieval operation.
[0026] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.
Claims
1. A socketed fish spear, characterized in that The device includes an outer cylinder, a mandrel, a slip seat, and a slip assembly. The lower side of the outer cylinder has an upward-opening mounting hole. Corresponding to the upper part of the mounting hole, the outer side of the outer cylinder has several balance holes that can communicate with the mounting hole. The mandrel has a vertically penetrating flow channel in the middle. The mandrel includes a large-diameter section, a small-diameter section, and a tapered tube section. The large-diameter section is located in the mounting hole below the balance hole. The lower end of the large-diameter section has a small-diameter section located below the outer cylinder. The lower end of the small-diameter section has a tapered tube section that is shaped like a frustum with a smaller upper diameter and a larger lower diameter. The outer side of the middle part of the large-diameter section has several sliding holes. The sliding holes are oblong holes. Corresponding to the upper part of each sliding hole, the outer side of the outer cylinder has a sliding screw with its inner end located in the sliding hole. The upper outer side of the small-diameter section is fixedly installed with a slip seat by a shear pin. The lower inner side of the slip seat has a mounting ring groove. The slip assembly with its lower end located on the upper outer side of the tapered tube section is limited and installed in the mounting ring groove. The lower inner side of the slip assembly has a tapered hole that matches the tapered tube section.
2. The shallow-water fish-catching spear according to claim 1, characterized in that... The slip assembly includes a slip cylinder and a pressure cap. The upper outer side of the slip cylinder is provided with a limiting ring platform located in the limiting ring groove. The lower outer side of the slip cylinder is provided with several annular retrieval teeth spaced vertically. The slip cylinder includes at least two separately arranged slip pieces. The lower outer side of the slip seat is fixedly installed with a pressure cap located below it. The lower inner side of the pressure cap is provided with a mounting ring platform. The lower end of the limiting ring platform sits on the upper side of the mounting ring platform.
3. The shallow-water fish-catching spear according to claim 2, characterized in that... The slip assembly also includes set screws. A pressure cap with its lower end located below it is fixedly installed on the outer side of the lower end of the slip seat via a threaded connection. At least two set screws are provided on the outer side of the upper part of the pressure cap along the circumference to fix the pressure cap and the slip seat together.
4. The shallow-water fish-catching spear according to claim 2 or 3, characterized in that... The slip assembly also includes clamping rings. An upper clamping ring groove is provided on the outer side of the middle of the limiting ring platform, and a lower clamping ring groove is provided on the outer side of the slip cylinder corresponding to the position between the pressure cap and the annular retrieval tooth. Clamping rings are provided in both the upper and lower clamping ring grooves.
5. The shallow-water fish-catching spear according to claim 1, 2, or 3, characterized in that... The outer side of the upper part of the outer cylinder and the outer side of the upper part of the large diameter section are both provided with retrieval ring grooves.
6. The shallow-water fish-catching spear according to claim 4, characterized in that... The outer side of the upper part of the outer cylinder and the outer side of the upper part of the large diameter section are both provided with retrieval ring grooves.
7. The shallow-water fish-catching spear according to claim 1, 2, 3, or 6, characterized in that... Four balance holes are evenly distributed along the circumference on the upper outer side of the outer cylinder, four sliding holes are evenly distributed along the circumference on the middle outer side of the large diameter section, and four shear pins are evenly distributed along the circumference on the upper outer side of the small diameter section.
8. The shallow-water fish-catching spear according to claim 4, characterized in that... Four balance holes are evenly distributed along the circumference on the upper outer side of the outer cylinder, four sliding holes are evenly distributed along the circumference on the middle outer side of the large diameter section, and four shear pins are evenly distributed along the circumference on the upper outer side of the small diameter section.
9. The shallow-water fish-catching spear according to claim 5, characterized in that... Four balance holes are evenly distributed along the circumference on the upper outer side of the outer cylinder, four sliding holes are evenly distributed along the circumference on the middle outer side of the large diameter section, and four shear pins are evenly distributed along the circumference on the upper outer side of the small diameter section.
10. The shallow-water fish-catching spear according to claim 1, 2, 3, 4, 5, 6, 7, 8, or 9, characterized in that... It also includes a rope cap, a weight bar, and a shock absorber. The rope cap, weight bar, shock absorber, and outer cylinder are installed together from top to bottom by threaded connections.