A cylindrical fish-catching tool for underground wells

Abstract

The utility model relates to the technical field of salvage tools, and provides a downhole cylindrical fish salvage tool, comprising an upper joint, a lower pressure cylinder and an outer cylinder axially connected in sequence, an oil chamber being provided between the lower pressure cylinder and the outer cylinder; a piston, the tail end of the piston being adapted to be installed in the lower pressure cylinder, and the front end of the piston extending from the lower pressure cylinder and the outer cylinder; a lifting cylinder, the lifting cylinder being connected to the piston; a slip, the lifting cylinder being connected to the slip, and the front end of the lifting cylinder being against the opening of the slip; when the upper joint and the lower pressure cylinder move downward to squeeze the oil chamber, the oil pressure drives the lifting cylinder to move upward to push the slip outward. The utility model makes it more convenient to salvage fallen fish, and after the salvage is completed, the slip and the lifting cylinder can be easily restored to their initial state.

Description

Technical Field

[0001] The utility model relates to the technical field of fishing tools, in particular to an underground cylindrical fish fishing tool. Background Art

[0002] When drilling enters the middle and late stages, the well depth increases continuously and the drill string gradually becomes longer, which can easily cause downhole accidents, such as drill string breakage or the lower drilling tool falling into the bottom of the well to form a fish, which can seriously cause the oil and gas well to be scrapped. When a fish appears at the bottom of the well, a salvage device is generally used to bite the fish, then lift the fish out of the bottom of the well and remove it. However, after some salvage devices are completed, the slips and the mandrel are easily stuck and difficult to separate and restore to the initial state. Utility Model Content

[0003] The utility model aims to provide an underground cylindrical fish salvaging tool which can be used for salvaging more conveniently and the slips and the core shaft can be easily separated.

[0004] The embodiment of the utility model is realized through the following technical scheme: a downhole cylindrical fish salvage tool, comprising an upper joint, a lower pressure cylinder and an outer cylinder axially connected in sequence, an oil chamber is provided between the lower pressure cylinder and the outer cylinder; a piston, the tail end of the piston is adapted to be installed in the lower pressure cylinder, and the front end of the piston extends from the lower pressure cylinder and the outer cylinder; a lifting cylinder, the lifting cylinder is connected to the piston; a slip, the lifting cylinder is connected with the slip, and the front end of the lifting cylinder is against the opening of the slip; when the upper joint and the lower pressure cylinder move downward to squeeze the oil chamber, the oil pressure drives the lifting cylinder to move upward to push the slip outward.

[0005] Preferably, a plurality of elastic locking pin assemblies are embedded and installed on the inner wall of the lower pressure cylinder, and the elastic locking pin assemblies include a first spring and a pin; and a plurality of locking notches corresponding to the pins are provided on the inner wall of the outer cylinder.

[0006] Preferably, the front end of the pin adopts an arc-shaped curved surface structure.

[0007] Preferably, it further comprises a second spring, wherein the second spring is sleeved on the tail end of the lifting cylinder, and the two ends of the second spring are respectively in contact with the slip and the outer cylinder.

[0008] Preferably, the slip is provided with a plurality of claw plates which are evenly spaced around the slip, and claw teeth are provided on the outer surfaces of the claw plates.

[0009] Preferably, the front end of the lifting cylinder adopts a conical head structure.

[0010] Preferably, the lifting cylinder is detachably connected to the piston, and the lifting cylinder is threadedly connected to the lower end of the piston.

[0011] Preferably, a first sealing ring is embedded at the point where the piston contacts the inner wall of the lower pressure cylinder.

[0012] Preferably, a second sealing ring is provided between the piston and the outer cylinder.

[0013] The technical solution of the embodiment of the utility model has at least the following advantages and beneficial effects: 1. The utility model is convenient for grabbing the fallen fish by applying downward pressure to the drill string and the upper joint, has good gripping strength, and can achieve unblocking without well fluid pressure and shearing pins;

[0014] 2. The slips are easy to replace to adapt to fish of different diameters, making it more practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 A schematic diagram of the structure of a cylindrical fish-catching tool for a well provided in an embodiment of the utility model;

[0017] Figure 2 for Figure 1 The cross-sectional view at AA in FIG.

[0018] Figure 3 for Figure 1 A local enlarged view of point B in FIG.

[0019] Figure 4 It is a structural schematic diagram of the lower pressure cylinder;

[0020] Figure 5 It is a schematic diagram of the structure of the outer cylinder;

[0021] Figure 6 It is a structural schematic diagram of the lifting cylinder;

[0022] Figure 7 It is a schematic diagram of the structure of Kava;

[0023] Figure 8 A schematic diagram of the pin structure.

[0024] Icons: 1-upper joint, 2-lower pressure cylinder, 21-installation port, 3-outer cylinder, 31-locking slot, 32-oil chamber, 4-piston, 5-upper lifting cylinder, 6-claw, 61-claw plate, 611-claw teeth, 7-second spring, 8-elastic locking pin assembly, 81-pin, 82-first spring, 9-first sealing ring, 10-second sealing ring. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0028] Example

[0029] The following is further described in conjunction with specific embodiments. Figure 1-Figure 8As shown, the present embodiment is a downhole cylindrical fish salvaging tool, comprising an upper joint 1, a lower pressure cylinder 2 and an outer cylinder 3 which are axially connected in sequence, an oil chamber 32 being provided between the lower pressure cylinder 2 and the outer cylinder 3; a piston 4, the tail end of the piston 4 being adapted to be installed in the lower pressure cylinder 2, and the front end of the piston 4 extending from the lower pressure cylinder 2 and the outer cylinder 3; an upper lifting cylinder 5, the upper lifting cylinder 5 being connected to the piston 4; a slip 6, the upper lifting cylinder 5 being connected to the slip 6, and the front end of the upper lifting cylinder 5 being against the opening of the slip 6; when the upper joint 1 and the lower pressure cylinder 2 move downward to squeeze the oil chamber 32, the oil pressure drives the upper lifting cylinder 5 to move upward to The cava 6 is stretched outward; specifically, when the salvage device is lowered to the place where the fish falls, the lower end surface of the outer cylinder 3 is against the fallen fish, and then the upper joint 1 and the lower pressure cylinder 2 move downward to squeeze the oil chamber 32, so that a part of the lubricating oil enters the lower pressure cylinder 2, and the oil pressure drives the piston 4 and the upper lifting cylinder 5 to move upward, and then the upper lifting cylinder 5 squeezes the cava 6 to open and grasp the inner wall of the fallen fish and maintain this state. The salvage operation is very convenient; and when it is necessary to release the jam, it is only necessary to pull the upper joint 1 relative to the outer cylinder 3 so that all the lubricating oil returns to the oil chamber 32, and then the cava 6 is separated from the upper lifting cylinder 5, and the jam is relatively easy to release.

[0030] Reference Figure 1 and Figure 2 As shown, the inner wall of the lower pressure cylinder 2 in this embodiment is embedded with a plurality of elastic locking pin assemblies 8, and the elastic locking pin assemblies 8 include a first spring 82 and a pin 81; the inner wall of the outer cylinder 3 is provided with a plurality of locking grooves 31 corresponding to the pins 81; specifically, when the lower pressure cylinder 2 squeezes the oil chamber 32 and the elastic locking pin assembly 8 moves vertically to the locking groove 31, the pin 81 is pressed into the locking groove 31 under the elastic force of the first spring 82, and in this state, the cava 6 grasps the inner wall of the fish falling, and the locked state can be maintained.

[0031] In order to facilitate the card release, the front end of the pin 81 adopts an arc-shaped curved surface structure, such as Figure 8 As shown, both ends of the locking groove 31 may also have guiding curved surfaces. When the lower pressing cylinder 2 rotates relative to the outer cylinder 3, the pin 81 squeezes the first spring 82 and moves out of the locking groove 31, and then the outer cylinder 3 and the lower pressing cylinder 2 produce a certain axial movement and restore the initial state.

[0032] This embodiment also includes a second spring 7, which is sleeved on the tail end of the lifting cylinder 5, and the two ends of the second spring 7 are respectively abutted against the cava 6 and the outer cylinder 3; specifically, when the lifting cylinder 5 moves upward, the second spring 7 abuts the cava 6 to prevent synchronous displacement with the lifting cylinder 5.

[0033] Reference Figure 7 As shown, the slip 6 is provided with a plurality of claw plates 61 which are evenly spaced around, and claw teeth 611 are provided on the outer surface of the claw plates 61; specifically, it helps to improve the firm grip of the claw plates 61 on the inner wall of the fallen fish.

[0034] like Figure 6 As shown, the front end of the lifting cylinder 5 in this embodiment adopts a conical head structure; specifically, the front end surface of the claw plate 61 fits with the conical head to achieve slow opening and diameter expansion.

[0035] like Figure 1 As shown, the lifting cylinder 5 is detachably connected to the piston 4, and the lifting cylinder 5 is threadedly connected to the lower end of the piston 4; in order to adapt to the salvage of fish of different calibers and to facilitate the replacement of the cava 6 and the lifting cylinder 5, the lifting cylinder 5 can be unscrewed from the piston 4.

[0036] Reference Figure 1 As shown, a first sealing ring 9 is embedded in the place where the piston 4 and the inner wall of the lower pressure cylinder 2 are in contact, so as to prevent the lubricating oil from leaking from between the piston 4 and the inner wall of the lower pressure cylinder 2.

[0037] In order to prevent the lubricating oil from leaking out from the gap between the outer cylinder 3 and the piston 4, resulting in insufficient oil pressure to lift the lifting cylinder 5, a second sealing ring 10 is provided at the contact between the piston 4 and the outer cylinder 3.

[0038] Working principle: when there is a fish that needs to be salvaged, lower the device into the fish until the upper end of the fish touches the lower end surface of the outer tube 3. At this time, the upper drill string is pressed downward to make the lower pressure tube 2 move downward to squeeze the lubricating oil. The piston 4 moves upward under the squeeze of the lubricating oil to drive the lifting tube 5 to lift up. When the lifting tube 5 is lifted upward with the piston 4, the extrusion slope squeezes the slope of the slip 6, so that the slip 6 opens outward to grasp the inner wall of the fish. The slip 6 will not move upward under the action of the large spring. When the lower pressure tube 2 is pressed down to the bottom, the pin 81 with the oval head is aligned with the locking notch 31. The pin 81 with the oval head moves forward under the action of the first spring 82 to clamp the downward pressure so that it cannot move up and down. At this time, the drill string can be lifted to salvage the fish.

[0039] When the fish is too heavy to be salvaged and needs to be unstuck, the upper drill string is rotated to rotate the upper joint 1 and the lower pressure cylinder 2 together, and the flat round head pin 81 is squeezed back into the installation opening 21 to unstuck and lift up.

[0040] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may be subject to various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A cylindrical fish catching tool for underground wells, characterized in that: It comprises an upper joint (1), a lower pressure cylinder (2) and an outer cylinder (3) which are axially connected in sequence, and an oil chamber (32) is provided between the lower pressure cylinder (2) and the outer cylinder (3); A piston (4), wherein the rear end of the piston (4) is adapted to be installed in the lower pressure cylinder (2), and the front end of the piston (4) extends out from the lower pressure cylinder (2) and the outer cylinder (3); A lifting cylinder (5), wherein the lifting cylinder (5) is connected to the piston (4); Slip (6), the lifting cylinder (5) is connected with the slip (6), and the front end of the lifting cylinder (5) is against the opening of the slip (6); When the upper joint (1) and the lower pressure cylinder (2) move downward to squeeze the oil chamber (32), the oil pressure drives the upper lifting cylinder (5) to move upward to push the slip (6) outward.

2. The downhole cylindrical fish salvaging tool according to claim 1, characterized in that: A plurality of elastic locking pin assemblies (8) are embedded and installed on the inner wall of the lower pressure cylinder (2), and the elastic locking pin assemblies (8) include a first spring (82) and a pin (81); The inner wall of the outer cylinder (3) is provided with a plurality of locking notches (31) corresponding to the pins (81).

3. The downhole cylindrical fish salvaging tool according to claim 2, characterized in that: The front end of the pin (81) adopts an arc-shaped curved surface structure.

4. The downhole cylindrical fish salvaging tool according to any one of claims 1 to 3, characterized in that: It also includes a second spring (7), which is sleeved on the tail end of the lifting cylinder (5), and the two ends of the second spring (7) are respectively in contact with the slip (6) and the outer cylinder (3).

5. The downhole cylindrical fish salvaging tool according to claim 1, characterized in that: The slip (6) is provided with a plurality of claw plates (61) which are evenly spaced around the claw plates, and claw teeth (611) are provided on the outer surfaces of the claw plates (61).

6. The downhole cylindrical fish salvaging tool according to claim 1, characterized in that: The front end of the lifting cylinder (5) adopts a conical head structure.

7. The downhole cylindrical fish salvaging tool according to claim 1, characterized in that: The lifting cylinder (5) is detachably connected to the piston (4), and the lifting cylinder (5) is threadedly connected to the lower end of the piston (4).

8. The downhole cylindrical fish salvaging tool according to claim 1, characterized in that: A first sealing ring (9) is embedded in the area where the piston (4) and the inner wall of the lower pressure cylinder (2) are in contact.

9. The downhole cylindrical fish salvaging tool according to claim 1, characterized in that: The piston (4) is in contact with the outer tube (3) and is provided with a second sealing ring (10).

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