A rubber fishing spear for fishing low strength pipe strings

Abstract

This utility model discloses a rubber retrieval spear for retrieving low-strength tubing strings, including a connector, a guide, and a multi-faceted spear shaft, which are sequentially connected. At least two cup units are fitted onto the multi-faceted spear shaft, each cup unit comprising a sequentially arranged isolation sleeve and a conical cup. When the retrieval spear enters the low-strength tubing string, the conical cup is compressed, forming a tight seal with the inner wall of the low-strength tubing string. As the tubing string is lifted, the compressed conical cup generates friction with the inner wall of the low-strength tubing string, propelling the low-strength tubing string upwards. This utility model improves the efficiency of retrieving low-strength tubing strings such as corroded or glass tubing strings, reduces the probability of tubing string breakage, and increases retrieval efficiency.

Description

Technical Field

[0001] This utility model relates to the field of well repair and retrieval technology, specifically a rubber retrieval spear for retrieving low-strength tubing. Background Technology

[0002] After prolonged production, oil and gas wells experience gradual corrosion of the tubing due to high temperatures, high pressures, hydrogen sulfide, and the corrosive effects of oil, gas, and water. This leads to brittle tubing with significantly reduced strength. Using conventional fishing spears for retrieval can easily cause the tubing to rupture and tear, resulting in failed retrieval and damage to the fish head. Using milling shoes generates a large amount of metal fragments, posing a high risk of stuck pipe, and is time-consuming, inefficient, and inefficient, incurring high equipment and personnel costs. Therefore, there is an urgent need to solve the problem of retrieving low-strength tubing.

[0003] Announcement No. CN220302094U discloses an anti-deviation retrieval spear. The spear body is connected to an external telescopic drill rod via a positioning seat. A connecting rod is connected to an external telescopic cylinder via a pull buckle. When the spear body reaches the object's vicinity, the external electric telescopic rod is energized, pulling the pull buckle and causing the connecting rod to move upwards. At this time, the fixed rod moves upwards, and due to the lever principle, the retrieval rod swings counterclockwise and extends outwards, then moves the spear body upwards, thereby retrieving the object. The angle can also be adjusted by rotating the spear body at the lower end of the positioning seat, and deviation is prevented under the action of the positioning cylinder.

[0004] The existing technology involves contact between the retrieval rod and the pipe string being retrieved, which is a point contact. Under high pressure, the pipe string, which has reduced strength, will deform or break at the contact point with the retrieval rod, resulting in retrieval failure.

[0005] Announcement No. CN114183088B discloses a retractable retrieval spear for oilfields, designed to prevent the slip from jamming. The spear includes slips, a sealing assembly, and a pressure-bearing assembly. The sealing assembly has three annular arrays slidably connected in the middle of the slip's interior. The pressure-bearing assembly has three annular arrays slidably connected on the upper side of the slip's interior. By employing water pressure variation, the spear retraction process is made simpler and smoother, preventing the slips from jamming with the fish. Simultaneously, through water pressure variation and pneumatic transmission, the slips are prevented from slipping or disengaging, ensuring that they can either lock or release the fish during retrieval, thus facilitating retraction.

[0006] The existing technology uses slips to contact the pipe string being retrieved. However, the slips cannot guarantee uniform contact with the pipe string, and the pipe string with reduced strength will deform or break, resulting in retrieval failure.

[0007] Announcement No. CN204113177U discloses a hydraulically retractable inverted retrieval device. The outer ring rotating clip is automatically rotated and replaced by the gravity of the retrieved object and the upward gradual pulling force. The outer ring clip is fixed by hydraulic drive, which gives a radial torque to the lower retrieval spear and allows the retrieval spear to be adjusted back.

[0008] The existing technology involves making contact with the salvaged pipe string by inverting the connection. The weakened connection of the pipe string reduces its strength and may cause a disengagement accident, resulting in salvage failure.

[0009] In summary, the technical solutions, technical problems to be solved, and beneficial effects of the above-disclosed technologies are all different from those of this utility model. For more technical features, technical problems to be solved, and beneficial effects of this utility model, the above-disclosed technical documents do not provide any technical inspiration. Utility Model Content

[0010] In view of the above-mentioned defects in the existing technology, the purpose of this utility model is to provide a rubber retrieval spear for retrieving low-strength tubular columns.

[0011] To achieve the above objectives, the present invention adopts the following technical solution:

[0012] This utility model provides a rubber retrieval spear for retrieving low-strength pipe columns, including a connector, a guide, and a multi-faceted spear shaft; the connector, the multi-faceted spear shaft, and the guide are connected in sequence; at least two cup units are fitted on the multi-faceted spear shaft, and the cup unit includes an isolation sleeve and a conical cup arranged in sequence.

[0013] Furthermore, the conical cup includes wear-resistant rubber and a polygonal metal liner;

[0014] Specifically, the wear-resistant rubber has a shape that is larger at the top and smaller at the bottom, with a tapered transition;

[0015] Specifically, the wear-resistant rubber has a polygonal metal liner inside, and a longitudinal metal support skeleton is provided on the outside of the polygonal metal liner. The metal support skeleton is embedded in the wear-resistant rubber.

[0016] Furthermore, the multi-faceted spear shaft has a limiting base between the last conical leather cup and the guide shoe, and the limiting base encloses the bottom of the last conical leather cup.

[0017] Furthermore, the connector is an upper joint, and the guide is a shoe guide;

[0018] Specifically, the upper connector, the multi-faceted spear shaft, and the center of the guide shoe are provided with a through water hole.

[0019] Furthermore, the outer surface of the upper connector is provided with a positive and negative snap marking groove;

[0020] Specifically, the upper connector is provided with a retrieval tube connection internal thread at the end away from the multi-faceted spear rod;

[0021] Specifically, the upper connector is provided with a spear rod connecting internal thread at one end, and the internal thread of the retrieval string is in the same direction as the internal thread of the spear rod connecting internal thread.

[0022] Furthermore, the multi-faceted spear shaft has a multi-faceted high-strength body in the middle, and the high-strength body is connected to the conical leather cup, the isolation sleeve, and the limiting base through a multi-faceted fit. The two ends of the multi-faceted spear shaft are threaded joints, and the multi-faceted spear shaft is connected to the upper joint and the guide shoe through threads.

[0023] Furthermore, the multi-faceted spear shaft has three to six edges.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] This invention improves the efficiency of retrieving low-strength tubing such as corroded tubing or glass tubing from wells, reduces the probability of tubing breakage, and increases retrieval efficiency. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of a rubber retrieval spear for retrieving low-strength tubular columns according to this utility model;

[0027] Figure 2 This is a schematic diagram of the upper connector in this utility model;

[0028] Figure 3 This is a schematic diagram of the structure of the hexagonal spear shaft in this utility model;

[0029] Figure 4 This is a schematic diagram of the conical leather cup in this utility model;

[0030] Figure 5 This is a schematic diagram of the structure of the isolation sleeve in this utility model;

[0031] Figure 6 This is a schematic diagram of the structure of the limiting base in this utility model;

[0032] Figure 7 This is a schematic diagram of the structure of the shoe in this utility model.

[0033] In the diagram: 1. Upper connector; 101. Reverse thread marking groove; 102. Internal thread for retrieval string connection; 103. Water eye for upper connector; 104. Internal thread for spear shaft connection;

[0034] 2. Hexagonal spear shaft; 201. High-strength body; 202. External thread for hexagonal spear shaft connection; 203. Water eye for hexagonal spear shaft;

[0035] 3. Conical leather cup; 301. Wear-resistant rubber; 302. Hexagonal metal liner; 303. Metal support frame; 304. Hexagonal through hole in the conical leather cup;

[0036] 4. Isolation sleeve; 401. Housing; 402. Hexagonal through hole in the isolation sleeve;

[0037] 5. Limiting base; 501. Body; 502. Leather cup base; 503. Hexagonal through hole in the base;

[0038] 6. Shoe guide; 601. Connecting thread; 602. Shoe guide water eye. Detailed Implementation

[0039] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0040] Example 1:

[0041] Please see Figures 1 to 7 The present invention provides a rubber retrieval spear for retrieving low-strength pipe columns, comprising an upper connector 1, a hexagonal spear shaft 2, and a guide shoe 6 connected in sequence. The hexagonal spear shaft 2 is fitted with at least two leather cup units, each of which includes an isolation sleeve 4 and a conical leather cup 3 arranged in sequence. A limiting base 5 is provided between the last conical leather cup 3 and the guide shoe on the hexagonal spear shaft 2.

[0042] The function of the upper connector 1 is to facilitate the connection threads at both ends, which are connected to the upper tubing and the hexagonal spear 2 respectively, and a water hole is set in the middle for circulation and well washing operations.

[0043] Among them, the hexagonal spear shaft 2 serves as a carrier, assembling the isolation sleeve 4, the conical leather cup 3, and the limiting base 5 together. The middle part is hexagonal, which can transmit torque when rotating, driving the conical leather cup 3 to rotate.

[0044] Among them, the isolation sleeve 4 can separate adjacent conical cups 3, increase the distribution length of the conical cups 3, and prevent the conical cups 3 from directly contacting and interfering with each other.

[0045] The conical cup 3 is composed of an outer rubber and an inner hexagonal metal liner 302. The rubber is used to generate friction with the inner wall of the oil pipe, driving the oil pipe upward. The hexagonal metal liner 302 is vulcanized together with the rubber and contacts the high-strength body 201 of the hexagonal spear 2. It can transmit torque and prevent the rubber from being damaged when the hexagonal spear 2 rotates.

[0046] Among them, the limiting base 5 contacts the bottom of the conical leather cup 3, wrapping the bottom of the conical leather cup 3 inside, to prevent the bottom of the conical leather cup 3 from directly contacting the falling fish and causing wear, and the bottom of the limiting base 5 contacts the guiding shoe 6.

[0047] The guide shoe and the 6-hexagonal spear rod 2 are connected by threads, and there is a water hole in the middle for well washing operations, while also providing support for the limit base 5.

[0048] During assembly, first connect the hexagonal spear shaft 2 to the upper connector 1, then sequentially insert the corresponding number of conical cups 3 and isolation sleeves 4, with the conical cups 3 and isolation sleeves 4 installed at intervals. Next, install the limiting base 5, and finally connect the guide shoe 6. The length of the hexagonal spear shaft 2 can be increased or decreased as needed, and the number of conical cups 3 and isolation sleeves 4 can also be increased or decreased accordingly.

[0049] After the tool is assembled, it is lowered into the well. Guided by the guide shoe 6, the wear-resistant rubber 301 of the conical cup 3 is compressed and squeezed into the inner cavity of the tubing to be retrieved. Under the action of the rubber's rebound force, it fits tightly against the inner wall of the tubing, and the retrieval is achieved by relying on its friction.

[0050] Example 2:

[0051] Based on Embodiment 1, specifically, the outer surface of the upper connector 1 is provided with a positive and negative buckle marking groove 101 to facilitate identification of the positive and negative rotation direction of the tool for installation.

[0052] The upper connector 1 is provided with a fishing string connection internal thread 102 at the end away from the hexagonal spear rod 2, which is used to connect the fishing string to the well. The female thread can be a left-hand thread or a right-hand thread.

[0053] The upper connector 1 is provided with an upper connector water eye 103 at its center. The upper connector water eye 103 is connected to the upper connector 1 and is used for the circulation and flushing of well washing fluid, well workover fluid and well kill fluid.

[0054] The upper connector 1 is provided with a spear rod connecting internal thread 104 at one end, which is used to connect the hexagonal spear rod 2. The female thread is in the same direction as the internal thread 102 of the retrieval column.

[0055] Specifically, the end of the shoe 6 connected to the hexagonal spear shaft 2 is provided with a connecting thread 601 for connecting to the hexagonal spear shaft 2, so that the multiple conical leather cups 3 and the multiple isolation sleeves 4 become a whole.

[0056] The guide shoe 6 has a guide shoe water eye 602 at its center. The guide shoe water eye 602 passes through the guide shoe 6 and is used for the circulation and flushing of well washing fluid, well repair fluid and well kill fluid.

[0057] Specifically, the hexagonal spear shaft 2 has a high-strength body 201 in the middle, which can fit the conical cup 3, the isolation sleeve 4 and the limiting base 5 on its outside, and transmit the torque of the retrieval column.

[0058] The hexagonal spear shaft 2 has hexagonal spear shaft connecting external threads 202 at both ends, which are used to connect the spear shaft connecting internal threads 104 of the upper connector 1 and the connecting threads 601 of the guide shoe 6.

[0059] The hexagonal spear shaft 2 has a through-hole 203 inside, which is used to connect the upper connector water hole 103 and the guide shoe water hole 602 to form a fluid flow channel for the circulation and flushing of well washing fluid, well repair fluid and well killing fluid.

[0060] Specifically, the conical cup 3 includes wear-resistant rubber 301 and a hexagonal metal liner 302. The wear-resistant rubber 301 is wider at the top and narrower at the bottom, with a tapered transition. The lower diameter of the wear-resistant rubber 301 is small, which facilitates its entry into the inner wall of the tubing to be retrieved. The upper diameter of the wear-resistant rubber 301 is large, which facilitates its close contact with the inner wall of the tubing after being compressed. The longer the large diameter portion of the wear-resistant rubber 301, the larger its contact area with the inner wall of the tubing to be retrieved, and the stronger the friction, which can easily achieve retrieval. Moreover, because the wear-resistant rubber 301 has high toughness, it is not easy to burst the tubing in the well, thus protecting the integrity of the tubing in the well.

[0061] The wear-resistant rubber 301 has a hexagonal metal liner 302 inside, and six longitudinal metal support skeletons 303 outside the hexagonal metal liner 302. The metal support skeletons 303 are embedded in the wear-resistant rubber 301. The wear-resistant rubber 301, the hexagonal metal liner 302, and the metal support skeletons 303 are cast into a whole by a vulcanization process, so that it can maintain high strength.

[0062] The hexagonal metal liner 302 has a conical cup-shaped hexagonal through hole 304 inside, which is used to fit around the outside of the hexagonal spear shaft 2, so that it can transmit torque.

[0063] Specifically, the outer part of the isolation sleeve 4 is a shell 401, which is cylindrical in shape and has the same diameter as the small end diameter of the bottom of the conical cup 3.

[0064] The isolation sleeve 4 has a hexagonal through hole 402 inside, which is used to fit over the outside of the connecting hexagonal spear rod 2 to isolate the adjacent conical cups 3.

[0065] Specifically, the outer part of the limiting base 5 is a body 401, which is cylindrical in shape and has a diameter larger than the diameter of the small end of the bottom of the conical cup 3.

[0066] The limiting base 5 has a hexagonal through hole 503 inside, which is used to fit over the outside of the connecting hexagonal spear rod 2.

[0067] The upper part of the limiting base 5 is a leather cup base 402. The leather cup base 402 is a cylindrical concave stepped surface. The diameter of the leather cup base 402 is the same as the diameter of the small end of the bottom of the conical leather cup 3, so that the leather cup base 402 can support the bottom of the conical leather cup 3 and wrap it to prevent it from being damaged by fish during the retrieval process.

[0068] This utility model provides a rubber retrieval spear for retrieving low-strength tubular columns. It uses a hexagonal spear shaft 2 as support and wear-resistant rubber 301 as the retrieval medium. Due to the elastic deformation of the wear-resistant rubber 301, it is compressed when the spear enters the low-strength tubular column. The wear-resistant rubber 301 of the conical cup 3 fits tightly against the inner wall of the column. As the column is lifted, the compressed wear-resistant rubber 301 generates friction with the inner wall of the low-strength tubular column, causing the column to move upwards.

[0069] Because of its large contact area, high toughness, and strong friction, the rubber is unlikely to damage the tubing, allowing for easy retrieval. If the tubing becomes stuck and cannot be pulled out, the retrieval tubing can be rotated, transmitting torque to the hexagonal spear shaft 2. Under the action of the hexagonal spear shaft 2, the conical cup 3 rotates. The wear-resistant rubber 301 rubs against the inner wall of the low-strength tubing, causing the rubber to wear down and reducing the friction between the conical cup 3 and the inner wall of the low-strength tubing, thus allowing the tubing to be destructively removed. This invention can directly retrieve low-strength tubing, improving the efficiency of handling complex situations and effectively reducing construction costs.

[0070] All components not discussed in detail in this application, as well as the connection methods of these components, are well-known technologies in this field. They can be directly applied and will not be elaborated further.

[0071] In this utility model, the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "linking" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0072] In the description of this utility model, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or unit 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 this utility model.

[0073] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0074] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A rubber fishing spear for fishing a low strength pipe string comprising a connector, a guide, characterized in that, It also includes multi-faceted spear shafts; The connector, the multi-faceted spear shaft, and the guide are connected in sequence; The multi-faceted spear shaft is fitted with at least two cup units, each cup unit comprising an isolation sleeve and a conical cup arranged sequentially.

2. The rubber retrieval spear for retrieving low-strength pipe columns according to claim 1, characterized in that, The conical cup includes wear-resistant rubber and a polygonal metal liner; The wear-resistant rubber has a shape that is larger at the top and smaller at the bottom, with a tapered transition. The wear-resistant rubber has a polygonal metal liner inside, and a longitudinal metal support skeleton is provided on the outside of the polygonal metal liner. The metal support skeleton is embedded in the wear-resistant rubber.

3. The rubber retrieval spear for retrieving low-strength pipe columns according to claim 1, characterized in that, The multi-faceted spear shaft has a limiting base between the last conical leather cup and the guide shoe, and the limiting base encloses the bottom of the last conical leather cup.

4. The rubber retrieval spear for retrieving low-strength pipe columns according to claim 3, characterized in that, The connector is an upper joint, and the guide is a shoe guide; The upper connector, the multi-faceted spear shaft, and the center of the guide shoe are provided with a through water hole.

5. A rubber retrieval spear for retrieving low-strength tubular columns according to claim 4, characterized in that, The outer surface of the upper connector is provided with a positive and negative buckle marking groove; The upper connector is provided with a retrieval tube string connection internal thread at the end away from the multi-faceted spear rod; The upper connector is provided with a spear rod connecting internal thread at one end, and the internal thread of the retrieval string is in the same direction as the internal thread of the spear rod connecting internal thread.

6. A rubber retrieval spear for retrieving low-strength tubular columns according to claim 4, characterized in that, The multi-faceted spear shaft has a multi-faceted high-strength body in the middle. The high-strength body is connected to the conical leather cup, the isolation sleeve, and the limiting base through a multi-faceted fit. The two ends of the multi-faceted spear shaft are threaded joints. The multi-faceted spear shaft is connected to the upper joint and the guide shoe through a threaded connection.

7. A rubber retrieval spear for retrieving low-strength pipe columns according to any one of claims 1-6, characterized in that, The multi-faceted spear shaft has three to six facets.

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