Hydraulic fishing spear and fishing device

Abstract

The utility model discloses a hydraulic fishing spear and a fishing device. The hydraulic fishing spear comprises a spear rod, a barrel and a slip, one end of the spear rod is used for being connected with a drill column and is provided with a connecting cavity, the connecting cavity is used for being communicated with a drill column water way, the barrel is arranged on the outer side of the spear rod in a sleeving mode and can slide relative to the spear rod, and a hydraulic cavity is formed between the barrel and the spear rod and is communicated with the connecting cavity water way. The slip is arranged at the end, away from the connecting cavity, of the spear rod and movably connected with the spear rod, and the barrel abuts against the slip and is movably connected with the slip. Water flow in the drill column enters the hydraulic cavity through the connecting cavity, so that the pressure in the hydraulic cavity is increased, when the pressure is increased to a preset degree, the barrel slides relative to the spear rod under the action of hydraulic pressure and pushes the slips to be tightly attached to the inner wall of the fish cavity, so that the spear rod is tightly clamped with the fish, and the drill column does not need to be rotated in the whole fishing process. Clamping and retracting of the slips can be controlled by adjusting the pressure of liquid in the drill stem, and time and labor are saved.

Description

Technical Field

[0001] The utility model relates to the technical field of oilfield workover tools, in particular to a hydraulic fishing spear and a fishing device. Background Art

[0002] A fishing spear is a tool for fishing through the inner hole of a fish (a fish refers to a downhole object, especially drill tools, tubing, drill pipes, casing, etc. left in the well due to accidents). It can fish and reverse buckle on different sizes of fish with a cylindrical inner cavity of tubing, drill pipes, casing, etc., and is widely used in oilfield workover operations.

[0003] After the traditional fishing spear enters the inner part of the fish cavity, it is necessary to release the slips by rotating the fishing spear so that the slips are clamped and fixed with the inner wall of the fish cavity. Since the fishing spear is in a very deep position during the fishing operation and cannot be directly rotated, it is necessary to drive the fishing spear to rotate by rotating the drill string. Rotating the drill string often requires a large external force, which is time-consuming and laborious. Summary of the Invention

[0004] In order to solve the problem that it is time-consuming and laborious to rotate the drill string to release the slips in the prior art, the utility model provides a hydraulic fishing spear and a fishing device.

[0005] A hydraulic fishing spear includes a spear rod, a cylinder body and a slip. One end of the spear rod is used for connecting with the drill string and is provided with a connecting cavity, and the connecting cavity is used for waterway connection with the drill string. The cylinder body is sleeved outside the spear rod and can slide relative to the spear rod. A hydraulic cavity is formed between the cylinder body and the spear rod, and the hydraulic cavity is in waterway connection with the connecting cavity. The slip is arranged at one end of the spear rod far from the connecting cavity and is movably connected with the spear rod. The cylinder body abuts against the slip and is movably connected with the slip.

[0006] Wherein, when the pressure of the liquid inside the hydraulic cavity reaches a predetermined level, the cylinder body can slide relative to the spear rod from a first predetermined position to a second predetermined position, and the slip is moved from a retracted state to a clamped state.

[0007] In some embodiments, the spear rod includes a connecting portion, a sleeved portion and a clamping portion. The connecting portion and the clamping portion are respectively arranged at opposite ends of the sleeved portion. The connecting portion is used for connecting with the drill string, the sleeved portion is used for sleeving the cylinder body, and the clamping portion is a conical structure for cooperating with the slip to fish the fish.

[0008] Wherein, the maximum outer diameters of the connecting portion and the clamping portion are both larger than the outer diameter of the cylinder body.

[0009] In some embodiments, the sleeving part includes a first part and a second part, and the diameter of the first part is greater than that of the second part;

[0010] One end of the cylinder body is provided with a movable cavity, and a slideway is provided on the bottom surface of the movable cavity, and the slideway communicates with the movable cavity;

[0011] Wherein, the first part is located at the open end of the movable cavity and closes the movable cavity to form the hydraulic cavity, and the second part is slidably arranged in the slideway and fits with the sliding side wall to close the slideway.

[0012] In some embodiments, the hydraulic fishing spear further includes a first elastic member, the first elastic member is arranged inside the hydraulic cavity, and the opposite ends of the first elastic member in the elastic direction are respectively fixedly connected to the first part and the cylinder body, and the first elastic member tightens the first part and the cylinder body to maintain the cylinder body at the first predetermined position.

[0013] In some embodiments, the spear rod further includes a one-way conduction structure, and the one-way conduction structure is arranged inside the second flow channel.

[0014] In some embodiments, along the direction from the connecting part to the clamping part, the outer diameter of the clamping part gradually increases uniformly to form the conical structure;

[0015] The slip sleeve is slidably connected to the side surface of the conical structure, and the cylinder body abuts against the slip sleeve along the direction in which the diameter of the conical structure increases.

[0016] In some embodiments, the inner diameter of the slideway on the side away from the movable cavity gradually increases to form a conical channel;

[0017] Wherein, when the cylinder body moves relative to the spear rod to the second predetermined position, the side wall of the conical channel matches and fits with the side surface of the conical structure.

[0018] In some embodiments, a first flow channel and a second flow channel are provided inside the spear rod, the first flow channel communicates the connecting cavity and the hydraulic cavity, and the second flow channel penetrates through the spear rod along the extending direction of the spear rod and communicates the connecting cavity.

[0019] In some embodiments, one of the cylinder body and the slip sleeve is provided with a slider, and the other of the cylinder body and the slip sleeve is provided with a chute, and the slider is slidably clamped inside the chute;

[0020] The hydraulic fishing spear further includes a second elastic member, the second elastic member is arranged inside the chute, and the second elastic member abuts against the slider along the sliding direction of the slider.

[0021] The present application also provides a fishing device, including the above hydraulic fishing spear.

[0022] Compared with the prior art, the hydraulic fishing spear in an embodiment of the present utility model has the following beneficial effects: The hydraulic fishing spear includes a spear rod, a cylinder body and a slip. One end of the spear rod is used for connecting with a drill string and is provided with a connection cavity which is used for waterway connection with the drill string. The cylinder body is sleeved outside the spear rod and can slide relative to the spear rod. A hydraulic cavity is formed between the cylinder body and the spear rod, and the hydraulic cavity is in waterway connection with the connection cavity. The water flow in the drill string can enter the hydraulic cavity through the connection cavity, so that the liquid pressure inside the hydraulic cavity increases. When the liquid pressure inside the liquid cavity increases to a predetermined level, the cylinder body can move from a first predetermined position to a second predetermined position under the action of the hydraulic pressure. The slip is arranged at one end of the spear rod away from the connection cavity and is movably connected with the spear rod. The cylinder body abuts against the slip and is movably connected with the slip. When the cylinder body moves from the first predetermined position to the second predetermined position, the slip can be pushed from the retracted state to the clamped state. In the clamped state, the slip is tightly pressed and fitted with the inner wall of the fish cavity. Then, during the process of lifting the spear rod, the spear rod and the fish are clamped tightly to fish up the fish. The above process does not require rotating the drill string during the whole fishing process, and only by adjusting the pressure of the liquid inside the drill string, the clamping and retraction of the slip can be controlled, which is time-saving and labor-saving. Description of the Drawings

[0023] Figure 1 is the overall structural schematic diagram of the slip in the retracted state in an embodiment of the present application;

[0024] Figure 2 is the overall structural schematic diagram of the slip in the clamped state in an embodiment of the present application;

[0025] Figure 3 is the explosion structural schematic diagram in an embodiment of the present application;

[0026] Figure 4 is Figure 3 the enlarged schematic diagram of the structure at A in

[0027] Figure 5 is the overall sectional structural schematic diagram of the slip in the retracted state in an embodiment of the present application;

[0028] Figure 6 is Figure 5 the enlarged schematic diagram of the structure at B in

[0029] Figure 7 is the overall sectional structural schematic diagram of the slip in the clamped state in an embodiment of the present application;

[0030] Figure 8 is Figure 7 the enlarged schematic diagram of the structure at C in

[0031] 100, spear rod; 11, connecting part; 12, sleeved part; 121, first part; 122, second part; 13, clamping part; 14, unidirectional conduction structure; 200, cylinder body; 21, slider; 300, slip tile; 31, chute; 400, first elastic part; 500, second elastic part; 01, connecting cavity; 02, moving cavity; 03, hydraulic cavity; 04, slideway; 001, first flow channel; 002, second flow channel. Detailed implementation mode

[0032] In order to enable those skilled in the art to better understand the technical solution of the present utility model, the present utility model will be described in detail below with reference to the accompanying drawings. The description of this part is only exemplary and explanatory, and should not have any restrictive effect on the protection scope of the present utility model.

[0033] It should be noted that similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0034] It should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the utility model product is usually placed during use. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present utility model. In addition, the terms "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0035] In addition, the terms "horizontal", "vertical", "hanging", etc. do not mean that the components are required to be absolutely horizontal or hanging, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present utility model belongs. The terms used in the description of the present utility model in this specification are only for the purpose of describing specific embodiments and are not intended to limit the present utility model.

[0037] The present utility model will be further described in detail below with reference to the accompanying drawings.

[0038] As Figure 1 , Figure 2 , Figure 3 , Figure 5, Figure 7 A kind of hydraulic fishing spear shown as follows, which comprises a spear rod 100, a cylinder 200 and slips 300. One end of the spear rod 100 is used for connecting a drill string. A water passage is arranged inside the drill string. A connection cavity 01 is formed at the end of the spear rod 100 where it is connected to the drill string. After the spear rod 100 is connected to the drill string, the connection cavity 01 is communicated with the water passage inside the drill string.

[0039] The cylinder 200 is sleeved outside the above-mentioned spear rod 100 and can slide relative to the spear rod 100. A hydraulic cavity 03 is formed between the cylinder 200 and the spear rod 100, and the hydraulic cavity 03 is in a communicated state with the connection cavity 01. The water flow inside the drill string can enter the hydraulic cavity 03 through the connection cavity 01. As the water flow continuously enters, the liquid pressure inside the hydraulic cavity 03 will increase. When the liquid pressure increases to a predetermined level, the cylinder 200 can slide relative to the spear rod 100 from a first predetermined position to a second predetermined position under the action of the liquid pressure.

[0040] The slips 300 are arranged at the end of the above-mentioned spear rod 100 far from the connection cavity 01 and are movably connected to the spear rod 100. One end of the above-mentioned cylinder 200 abuts against the slips 300 and can push the slips 300 to slide relative to the spear rod 100. When the cylinder 200 slides relative to the spear rod 100 from the first predetermined position to the second predetermined position, the cylinder 200 can push the slips 300 from the retracted state to the clamped state. In the retracted state, the slips 300 are in a separated state from the inner wall of the fish cavity (it should be noted that the fish refers to the downhole falling object, especially the drill string left in the well due to an accident. The fish cavity refers to the cavity or hole on the fish for clamping and fixing the fishing spear). The hydraulic fishing spear will not be clamped and fixed with the fish. In the clamped state, the slips 300 can be clamped and fixed with the inner wall of the fish cavity, so that the hydraulic fishing spear is clamped and fixed with the fish. Then, by lifting the hydraulic fishing spear, the fish can be fished out.

[0041] The overshot of the present application slides the cylinder 200 relative to the spear rod 100 by changing the pressure of the liquid inside the hydraulic chamber 03, thereby pushing the slips 300 to be clamped or disengaged from the fish cavity. In practical applications, when the hydraulic overshot is lowered into the fish cavity, the water flow inside the drill string is pressurized by a hydraulic pump, so that the pressure of the liquid inside the hydraulic chamber 03 between the spear rod 100 and the cylinder 200 of the hydraulic overshot increases. When the pressure of the liquid inside the hydraulic chamber 03 reaches a predetermined level, the cylinder 200 abuts against the slips 300 under the push of the liquid pressure, pushing the slips 300 into a clamped state to tightly adhere the slips 300 to the fish cavity. Then, the spear rod 100 is tightened and fixed to the fish through the slips 300. Then, the fish can be salvaged by lifting the spear rod 100 through the drill string. During the salvage process, there is no need to rotate the drill string. Only by adjusting the pressure of the liquid inside the drill string with a hydraulic pump can the clamping and retraction of the slips 300 be controlled, which saves time and effort.

[0042] The technical details of each component will be introduced one by one below.

[0043] In some embodiments, such as Figure 5 、 Figure 7 shown, the above-mentioned spear rod 100 includes a connecting portion 11, a sleeving portion 12 and a clamping portion 13. The connecting portion 11 and the clamping portion 13 are respectively arranged at opposite ends of the sleeving portion 12. The connecting portion 11 is used to connect with the drill string, the sleeving portion 12 is used to sleeve the cylinder 200, and the clamping portion 13 is a conical structure for cooperating with the slips 300 to tightly fix with the fish; and the maximum outer diameters of the connecting portion 11 and the clamping portion 13 are both larger than the outer diameter of the cylinder 200, so that the cylinder 200 can be restricted on the spear rod 100.

[0044] In some embodiments, such as Figure 3 、 Figure 5 、 Figure 7As shown in the figure, the above-mentioned sleeve part 12 includes a first part 121 and a second part 122, wherein the diameter of the first part 121 is larger than that of the second part 122. Correspondingly, one end of the above-mentioned cylinder 200 is provided with a movable cavity 02, a slideway 04 is provided on the bottom surface of the movable cavity 02, and the slideway 04 is in communication with the movable cavity 02. The first part 121 is located at the open end of the movable cavity 02 and closes the open end of the movable cavity 02. The second part 122 is movably arranged inside the slideway 04 and fits with the side wall of the slideway 04 to close the slideway 04. Through the above design, the first part 121 and the second part 122 respectively seal the open end of the movable cavity 02 and the slideway 04, and a closed hydraulic cavity 03 can be formed, and the hydraulic cavity 03 coincides with the above-mentioned movable cavity 02. When the pressure inside the hydraulic cavity 03 increases, it will generate pressure on the open edge of the slideway 04 close to the hydraulic cavity 03 to push the cylinder 200 to slide from the first predetermined position to the second predetermined position. Through the above method, only by adjusting the pressure of the liquid inside the hydraulic cavity 03 can the cylinder 200 be pushed to move, without other complex operations such as rotation, and the hydraulic structure is also very simple.

[0045] In some embodiments, as Figure 5 , Figure 7 shown, the hydraulic fishing spear further includes a first elastic member 400. The first elastic member 400 is arranged inside the hydraulic cavity 03. The opposite ends of the first elastic member 400 (the first elastic member 400 can be a kind of spring) in the elastic direction are respectively fixedly connected to the first part 121 and the cylinder 200. The first elastic member 400 is used to tension the cylinder 200 and the first part 121 to avoid the phenomenon that the cylinder 200 slides relative to the spear rod 100 due to gravity during the fishing process.

[0046] In some embodiments, as Figure 3 , Figure 5 , Figure 7 shown, along the direction from the above-mentioned connecting part 11 to the above-mentioned clamping part 13, the outer diameter of the above-mentioned clamping part 13 gradually increases to form the conical structure. The slips 300 are slidably connected to the side surface of the conical structure, and the cylinder 200 abuts against the slips 300 along the direction in which the diameter of the conical structure increases.

[0047] In practical applications, during the process of the cylinder 200 abutting against the slips 300 and moving, the slips 300 move along the direction in which the diameter of the conical structure increases. In this way, the outer side surface of the slips 300 can be gradually away from the side where the spear rod 100 is located, and then the diameter of the part where the slips 300 of the hydraulic fishing spear is located becomes larger to be clamped tightly with the side wall of the fish cavity. After the slips 300 are clamped tightly with the side wall of the fish cavity, when the spear rod 100 is lifted, the conical structure will generate a pressure to press the fish cavity on the slips 300, so that the slips 300 are clamped more tightly with the fish cavity. Furthermore, the fish can be fished out by lifting the spear rod 100.

[0048] In some embodiments, such as Figure 3 , Figure 5 , Figure 7 shown, the inner diameter of the side of the above chute 04 away from the movable cavity 02 gradually increases to form a tapered channel. When the cylinder body 200 moves relative to the spear rod 100 to the second predetermined position, the side wall of the tapered channel matches and fits with the side surface of the tapered structure. The tapered surface greatly increases the contact area between the spear rod 100 and the cylinder body 200, and thus can reduce the pressure generated by the spear rod 100 on the cylinder body 200 during the lifting process, playing a protective role for the cylinder body 200.

[0049] In some embodiments, such as Figure 5 , Figure 7 shown, a first flow channel 001 and a second flow channel 002 are formed inside the above spear rod 100. Among them, the first flow channel 001 communicates with the connection cavity 01 and the hydraulic cavity 03, and the second flow channel 002 penetrates through the spear rod 100 along the extending direction of the spear rod 100 and communicates with the connection cavity 01.

[0050] It can be understood that during the fishing process, a part of the water flow inside the drill string flows into the hydraulic cavity 03 through the first flow channel 001 to push the cylinder body 200 to move, and another part flows out from the end of the spear rod 100 away from the drill string through the second flow channel 002 to wash the fish-catching cavity. By the above method, it is possible to control the retraction and clamping of the slip 300 only by changing the pressure of the liquid inside the drill string through the cylinder body 200.

[0051] In some embodiments, such as Figure 5 , Figure 7 shown, the above spear rod 100 further includes a one-way conduction structure 14 (the one-way conduction structure 14 can be a one-way valve), and the one-way conduction structure 14 is arranged inside the second flow channel 002 to control the direction of the water flow inside the second flow channel 002.

[0052] In practical applications, if the fish gets stuck and cannot be fished, after the hydraulic fishing spear is engaged with the fish-catching cavity, the hydraulic pump can be operated in reverse to pump out the liquid inside the hydraulic cavity 03, and the hydraulic fishing spear can be moved downward by a certain distance. Under the action of negative pressure and the first elastic member 400, the cylinder body 200 moves upward and drives the slip 300 to move from the clamped state to the retracted state, so that the hydraulic fishing spear can be retrieved. By the above method, the hydraulic fishing spear can also be retrieved without rotating the drill string, which is convenient, fast, time-saving and labor-saving.

[0053] In some embodiments, one of the cylinder body 200 and the slip 300 is provided with a slider 21, and the other of the cylinder body 200 and the slip 300 is provided with a chute 31, and the slider 21 is slidably clamped inside the chute 31.

[0054] The hydraulic fishing spear further includes a second elastic member 500. The second elastic member 500 is disposed inside the chute 31 and abuts against the slider 21 along the sliding direction of the slider 21.

[0055] As Figure 5 、 Figure 7 shown, the above-mentioned slider 21 is arranged on the cylinder body 200, and the above-mentioned chute 31 is opened on the slip joint 300. Of course, the above-mentioned slider 21 can also be arranged on the slip joint 300, and then the above-mentioned chute 31 is opened on the cylinder body 200. Through the engagement of the slider 21 and the chute 31, in the sliding direction of the cylinder body 200, the positions of the cylinder and the slip joint 300 can be limited, so that during the reciprocating sliding of the cylinder body 200 between the first predetermined position and the second predetermined position, the slip joint 300 can be driven to reciprocate along the sliding direction of the cylinder body 200 to control the slip joint 300 to be in the clamped state or the retracted state.

[0056] In order to prevent the situation that the slip joint 300 gets stuck during the sliding between the clamped state and the retracted state between the slip joint 300 and the cylinder body 200, the second elastic member 500 is arranged inside the chute 31 to help the slip joint 300 move from the clamped state to the retracted state by abutting, so that the movement of the slip joint 300 is more stable.

[0057] This application also provides a fishing device, and the fishing device includes the above-mentioned hydraulic fishing spear.

[0058] In the description of the present invention, it should also be noted that unless otherwise clearly defined and limited, the terms "arranged", "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0059] It should be noted that, in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising said element.

[0060] Although the embodiments of the present utility model have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present utility model, and the scope of the present utility model is defined by the appended claims and their equivalents.

Claims

1. A hydraulic salvage spear, characterized in that: include: A spear rod (100), one end of which is used to be connected to a drill string and is provided with a connecting cavity (01), wherein the connecting cavity (01) is used to be connected to a water channel of the drill string; A cylinder (200), the cylinder (200) is sleeved on the outside of the lance (100) and can slide relative to the lance (100), a hydraulic chamber (03) is formed between the cylinder (200) and the lance (100), and the hydraulic chamber (03) is in water communication with the connecting chamber (01); A slip (300), wherein the slip (300) is arranged at one end of the lance (100) away from the connecting cavity (01) and is movably connected to the lance (100), and the cylinder (200) abuts against the slip (300) and is movably connected to the slip (300); When the pressure of the liquid in the hydraulic chamber (03) reaches a predetermined level, the cylinder (200) can slide from a first predetermined position to a second predetermined position relative to the lance (100), and move the slip (300) from a retracted state to a locked state.

2. The hydraulic salvage spear according to claim 1, characterized in that: The spear rod (100) comprises a connecting portion (11), a sleeve portion (12) and a clamping portion (13), wherein the connecting portion (11) and the clamping portion (13) are respectively arranged at opposite ends of the sleeve portion (12), the connecting portion (11) is used to be connected to a drill string, the sleeve portion (12) is used to be sleeved on the cylinder (200), and the clamping portion (13) is a conical structure and is used to cooperate with the slip (300) to salvage fallen fish; Wherein, the maximum outer diameters of the connecting portion (11) and the clamping portion (13) are both greater than the outer diameter of the cylinder (200).

3. The hydraulic salvage spear according to claim 2, characterized in that: The sleeve portion (12) comprises a first portion (121) and a second portion (122), wherein the diameter of the first portion (121) is greater than the diameter of the second portion (122); An active cavity (02) is provided at one end of the cylinder (200), a slideway (04) is provided on the bottom surface of the active cavity (02), and the slideway (04) is connected to the active cavity (02); The first part (121) is located at the open end of the movable cavity (02) and closes the movable cavity (02) to form the hydraulic cavity (03), and the second part (122) is slidably disposed on the slideway (04) and fits with the sliding side wall to close the slideway (04).

4. The hydraulic salvage spear according to claim 3, characterized in that: The hydraulic salvage spear further comprises a first elastic member (400), the first elastic member (400) being arranged inside the hydraulic chamber (03), the opposite ends of the first elastic member (400) in the elastic direction being respectively fixedly connected to the first part (121) and the cylinder (200), the first elastic member (400) tensioning the first part (121) and the cylinder (200) to maintain the cylinder (200) at the first predetermined position.

5. The hydraulic salvage spear according to claim 3, characterized in that: Along the direction from the connecting portion (11) to the clamping portion (13), the outer diameter of the clamping portion (13) increases uniformly and gradually to form the tapered structure; The slip (300) is slidably connected to the side of the conical structure, and the cylinder (200) abuts against the slip (300) along the direction in which the diameter of the conical structure increases.

6. The hydraulic fishing spear according to claim 5, characterized in that: The inner diameter of the slideway (04) on the side away from the active chamber (02) gradually increases to form a tapered channel; When the cylinder (200) moves to the second predetermined position relative to the lance (100), the side wall of the tapered channel matches and fits with the side surface of the tapered structure.

7. The hydraulic fishing spear according to claim 1, characterized in that: A first flow channel (001) and a second flow channel (002) are provided inside the lance (100); the first flow channel (001) connects the connecting chamber (01) and the hydraulic chamber (03); and the second flow channel (002) penetrates the lance (100) along the extension direction of the lance (100) and connects the connecting chamber (01).

8. The hydraulic fishing spear according to claim 7, characterized in that: The lance (100) further comprises a one-way conducting structure (14), wherein the one-way conducting structure (14) is arranged inside the second flow channel (002).

9. The hydraulic fishing spear according to claim 1, characterized in that: One of the cylinder (200) and the slip (300) is provided with a slider (21), and the other of the cylinder (200) and the slip (300) is provided with a slide groove (31), and the slider (21) is slidably locked inside the slide groove (31); The hydraulic salvage spear further comprises a second elastic member (500), wherein the second elastic member (500) is arranged inside the slide groove (31), and the second elastic member (500) abuts against the slide block (21) along the sliding direction of the slide block (21).

10. A salvaging device, characterized in that: The invention comprises the hydraulic fishing spear as described in any one of claims 1 to 9.

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