Fishing spear
By introducing a locking ring and ratchet design into the salvage spear, the problem of unsuccessful release of downhole tools due to insufficient spring force is solved, achieving higher release reliability and convenience of tool separation.
Patent Information
- Application Number
- CN202422881301.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-25
- Publication Date
- 2025-09-09
- Estimated Expiration
- 2034-11-25
AI Technical Summary
The failure of releasing downhole salvage tools when they become stuck is mainly due to insufficient spring force, which results in failure of the salvage operation.
The introduction of a locking ring and ratchet design into the structure of the salvage spear makes the relative movement between the core shaft and the locking ring one-way, ensuring that the core shaft can only move downward and the locking ring can only move upward when stuck, thereby improving the reliability of releasing the tool. The window opening of the claw sleeve and the ring groove or thread design of the claw seat facilitate the separation of the tool.
The reliability of the salvage tool in releasing when it is stuck is improved, the striking force is enhanced, the influence of underground debris is overcome, and the separation process of the tool and the salvage spear is simplified.
Smart Images
Figure CN223317823U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of oilfield development testing tools, and particularly relates to a fishing spear used for downhole testing operations, and is used to fish downhole testing tools, etc. Generally, the tool of the utility model is lowered into the oil pipe by steel wire for fishing operations, and sometimes also by continuous oil pipe. Background Art
[0002] During oilfield completion and testing operations, downhole tools such as plugs and pressure gauges are sometimes run into the tubing. After these operations are complete, a fishing tool must be lowered to retrieve the plug or pressure gauge from the tubing. Due to the unique nature of downhole operations, the fishing tool often becomes stuck. During a dedicated spear fishing operation, if a stuck tool is needed, the tool first cuts the shear pin downwards and then lifts up to release the tool. This specialized spear has two springs, one of which is larger and specifically used for releasing the tool. Sometimes, debris can get stuck in the spear, resulting in insufficient spring force and a failure to release the tool. Utility Model Content
[0003] In order to solve the above technical problems, the utility model provides a salvage spear, which solves the problem of insufficient spring force and unsuccessful release through strong locking in its structure, thereby improving the reliability of release.
[0004] In order to achieve the above purpose, the present invention adopts the following technical solutions:
[0005] A salvage spear, wherein an upper joint is threadedly connected to a core shaft, a shear sleeve is fitted on the core shaft, pin holes are arranged radially opposite to the core shaft, a shear pin is installed in the pin hole, a claw sleeve is fitted on the core shaft and threadedly connected to the shear sleeve, a stop sleeve is fitted in the annulus between the claw sleeve and the core shaft, a salvage claw is installed in a claw seat groove, the claw seat is fitted in the annulus between the stop sleeve and the claw sleeve, a spring is provided above the claw seat, a limiting step is provided at the lower part of the core shaft, the lower part of the salvage claw sits on the limiting step, an inner ring groove is provided in the shear sleeve, a lock ring is placed in the ring groove, and ratchets are provided on the lock ring and the core shaft respectively to cooperate with each other.
[0006] Preferably, the claw sleeve has a window on its side wall above the fishing claw, and the windows are symmetrically arranged. Furthermore, the outer wall of the claw seat is provided with an annular groove or a thread.
[0007] Preferably, the ratchet is a sawtooth thread. The shear pin is made of brass.
[0008] Compared with the prior art, the advantages of the present invention are:
[0009] The utility model provides a salvage spear with a locking ring disposed between the core shaft and the claw sleeve, and ratchet teeth disposed between the locking ring and the core shaft, particularly a sawtooth threaded connection. When the core shaft descends and the spear is struck after a jam, its displacement is locked by the locking ring, and the spear claw is separated from the limiting step and can be released by lifting. Under the action of the weighted rod, the downward striking force is greater, making it easier to overcome the influence of underground debris on the tool. Therefore, the provision of a locking ring is more advantageous than a spring.
[0010] In addition, the claw sleeve is symmetrically provided with windows on the side wall above the salvage claw, and the outer wall of the claw seat is provided with an annular groove or a thread, which facilitates the separation of the salvaged tool from the salvage spear.
[0011] The technical solution of the present utility model is further described below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] When considered in conjunction with the accompanying drawings, the present invention can be more completely understood and many of the accompanying advantages can be easily known by referring to the detailed description below, but the drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The schematic embodiments of the present invention and their description are used to explain the present invention and do not constitute an improper limitation on the present invention.
[0013] Figure 1 The utility model is a structural schematic diagram of a salvage spear.
[0014] In the figure: 1-upper joint, 2-core shaft, 3-shear sleeve, 4-shear pin, 5-locking ring, 6-stop sleeve, 7-spring, 8-claw sleeve, 9-claw seat, 10-fishing claw. DETAILED DESCRIPTION
[0015] In the present specification and claims, the terms "upper" and "lower" in terms of positional relationship are described based on the state of the tool when it is in use, and will not be repeated in the following description.
[0016] Example 1
[0017] See also Figure 1 As shown, a salvage spear, the upper joint 1 is threadedly connected to the core shaft 2, the shear sleeve 3 is fitted on the core shaft, the shear sleeve and the core shaft are radially oppositely provided with pin holes, the shear pin 4 is installed in the pin hole, the claw sleeve 8 is fitted on the core shaft and threadedly connected to the shear sleeve 3, the stop sleeve 6 is fitted in the annulus between the claw sleeve and the core shaft, the salvage claw 10 is installed in the groove of the claw seat 9, the claw seat 9 is fitted in the annulus between the stop sleeve and the claw sleeve, a spring 7 is provided above the claw seat, a limiting step is provided at the lower part of the core shaft, the lower part of the salvage claw sits on the limiting step, an inner ring groove is provided in the shear sleeve 3, a lock ring 5 is placed in the ring groove, and the lock ring and the core shaft are respectively provided with ratchets to cooperate with each other.
[0018] Generally, the fishing claw has four petals, and the claw seat 9 is provided with corresponding grooves to match the fishing claw. Figure 1 As shown in , a return step is provided between the fishing claw and the claw seat. When the fishing claw catches the inner step of the plug or the pressure gauge, the core shaft 2 is struck down, and then the fishing claw is pushed up to withdraw the fishing spear.
[0019] The ratchet between the locking ring and the core shaft makes the relative movement between the core shaft and the locking ring one-way, that is, the core shaft can only move downward, and the locking ring can only move upward, thereby ensuring the reliable extraction of the fishing claw.
[0020] Example 2
[0021] Example 2 is an improvement on Example 1. With other technical features unchanged, the improvement is that the claw sleeve has windows on the side wall above the fishing claw, and the windows are symmetrically arranged.
[0022] With the above improvement, when the fishing claw catches the inner step of the plug or pressure gauge, the core shaft is struck down, and then the claw seat 9 is pushed up by hand through the window. The claw seat 9 drives the fishing claw upward through the return step to withdraw the fishing spear.
[0023] Example 3
[0024] Example 3 is a further improvement on Example 2. While other technical features remain unchanged, the improvement is that an annular groove or a thread is provided on the outer wall of the claw seat.
[0025] The benefit of the improvement is that an annular groove or a thread is provided on the outer wall of the claw seat, which increases the friction resistance between the outer wall of the claw seat and the hand, making the operation of withdrawing the salvage claw more convenient.
[0026] Example 4
[0027] Embodiment 4 is a preferred embodiment of embodiment 1. When other technical features remain unchanged, the preferred embodiment is that the ratchet is a sawtooth thread. The sawtooth thread is a standard thread and is easy to process.
[0028] Example 5
[0029] Example 5 is a preferred embodiment of Example 1. When other technical features remain unchanged, the preferred embodiment is that the shear pin is made of brass. Brass is a commonly used brittle material and is more conducive to stable shearing performance of the tool.
[0030] Obviously, many modifications and changes made by those skilled in the art based on the purpose of the present invention fall within the protection scope of the present invention.
Claims
1. A salvage spear, wherein an upper joint (1) is threadedly connected to a core shaft (2), a shear sleeve (3) is fitted over the core shaft, a pin hole is provided in the shear sleeve and the core shaft in radially opposite relationship, and a shear pin (4) is installed in the pin hole, characterized in that: The claw sleeve (8) is sleeved on the core shaft and is connected to the shear sleeve (3) by thread. The stop sleeve (6) is sleeved in the annulus between the claw sleeve and the core shaft. The salvage claw (10) is installed in the groove of the claw seat (9). The claw seat is sleeved in the annulus between the stop sleeve and the claw sleeve. A spring (7) is arranged above the claw seat. A limit step is arranged at the lower part of the core shaft. The lower part of the salvage claw sits on the limit step. An inner ring groove is arranged in the shear sleeve (3). A lock ring (5) is placed in the ring groove. Ratchets are respectively arranged on the lock ring and the core shaft to match each other.
2. A salvage spear according to claim 1, characterized in that: The claw sleeve has windows on its side wall above the fishing claw, and the windows are symmetrically arranged.
3. A salvage spear according to claim 2, characterized in that: The outer wall of the claw seat is provided with an annular groove or a thread.
4. A salvage spear according to claim 1, characterized in that: The ratchet is a sawtooth thread.
5. A salvage spear according to any one of claims 1 to 4, characterized in that: The shear pin material is brass.