Large-diameter engineering well casing precision fishing device

Abstract

The application discloses a large-diameter engineering well casing precision fishing device, which comprises a cylinder connected with the bottom of a drill pipe through a male joint at the top end and a fishing piece connected with the male joint at the bottom of the cylinder, and the fishing piece is inserted into the inner cavity of the casing in the well wall, and relates to the technical field of casing fishing. The large-diameter engineering well casing precision fishing device can sequentially convey steel particles between the fishing piece and the casing along the inner cavity of the drill pipe, the insertion pipeline, the through groove and the steel particle hole, and the steel particles are accumulated between the fishing piece and the casing. At this time, the fishing piece rotates to extrude and convey the steel particles downwards, the steel particles are clamped in the spiral grooves to increase the friction between the fishing piece and the casing, the casing can be effectively prevented from falling off the fishing piece, the stable clamping effect of the casing fishing can be provided, the casing slipping accident in the casing fishing operation process can be effectively prevented or reduced, the construction effect is ensured, and the casing can be fished to the ground by lifting the drill pipe.

Description

Technical Field

[0001] This invention relates to the technical field, specifically to a device for precise retrieval of large-diameter engineering well casings. Background Technology

[0002] During the casing installation process for large-diameter engineering wells such as coal mine gas drainage wells, drainage wells, and material feeding wells, casing may sometimes accidentally detach. Because the casing dimensions of large-diameter engineering wells are generally quite large, it is difficult to retrieve them using ordinary tools. Various casing retrieval tools have been developed both domestically and internationally (such as retractable slip retrieval cylinders, retractable slip retrieval spears, retrieval male cones, and retrieval female cones). These casing retrieval tools have complex structures, are time-consuming and labor-intensive to operate, and require some well workover equipment, resulting in relatively high operating costs. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a precision retrieval device for large-diameter engineering well casings, solving the aforementioned problems.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a large-diameter engineering well casing precision retrieval device, comprising a cylinder whose top end is connected to the bottom of the drill pipe via a male threaded connector and a retrieval component connected to the bottom of the cylinder via a male threaded connector. The retrieval component is inserted into the casing cavity within the well wall. The cylinder comprises an upper cylinder and a lower cylinder that slides within the upper cylinder via a pin. The upper cylinder has a limiting groove in its cavity to prevent the lower cylinder from falling off. The lower cylinder has a through-groove in its cavity for conveying steel particles. The upper cylinder has an insertion pipe extending into the through-groove cavity for inserting steel particles. The bottom of the through-groove has a steel particle hole for discharging steel particles.

[0005] The retrieval device includes a retrieval head, the surface of which has a spiral groove adapted to the surface of the steel pellets. During casing retrieval operations, the casing retrieval tool is connected to the drill pipe. The drill pipe drives the cylinder and retrieval device to rotate, lowering the casing retrieval tool into the well wall until it is inserted into the inner cavity of the casing, with the entire retrieval device located within the inner cavity of the casing. After the retrieval device is inserted into the inner cavity of the casing, the prepared steel pellets are dropped into the drill pipe. The steel pellets roll from the steel pellet hole on the retrieval device into the gap between the retrieval device and the inner wall of the casing, and the steel pellets follow the... The drill rod inner cavity, the insertion pipe, the through groove, and the steel pellet hole are sequentially conveyed between the retrieval part and the casing. The steel pellets accumulate between the retrieval part and the casing. At this time, the retrieval part rotates, squeezing and conveying the steel pellets downwards. The steel pellets are stuck in the spiral groove, increasing the friction between the retrieval part and the casing, which can effectively prevent the casing from falling off the retrieval part. It can provide a stable clamping effect for casing retrieval, effectively preventing or reducing casing slippage accidents during casing retrieval operations, ensuring construction results. Lifting the drill rod can retrieve the casing to the ground.

[0006] As a further aspect of the present invention: the retrieval component is a rigid conical body with conical ends and a frustum in the middle, the maximum outer diameter of the frustum being 6-10 mm smaller than the inner diameter of the casing to be retrieved.

[0007] As a further aspect of the present invention: the diameter of the steel pellet hole is Ф20mm, and it is arranged at the last thread of the male threaded connector at the bottom of the cylinder, and there are two of them.

[0008] As a further aspect of the present invention: a protrusion is provided at the connection between the bottom frustum and the conical body of the salvage component, and the distance between the outer side of the protrusion and the inner wall of the sleeve is less than the radius of the steel particle.

[0009] As a further aspect of the present invention: both ends of the cylinder are provided with male threaded connectors, and the top of the retrieval component is provided with a female threaded connector that is threadedly connected to the male threaded connector.

[0010] As a further aspect of the present invention: the central truncated column of the salvage component is designed to be larger at the top and smaller at the bottom, which allows the steel particles to accumulate at the bottom and prevents them from falling off.

[0011] As a further aspect of the present invention: a top block is slidably disposed within the inner cavity of the retrieval head via a sliding groove; an inclined surface is provided on one side of the top block; a lifting block is slidably connected within the inner cavity of the retrieval component; a pushing surface tangent to the inclined surface is provided on the side of the lifting block; a connecting rod is fixedly connected within the inner cavity of the upper column, passing sequentially through a pin and the lower column and extending into the inner cavity of the lower column; the bottom end of the connecting rod is fixedly connected to the top of the lifting block; when the drill rod is lifted, the upper column is lifted, and when the upper column is lifted, at this time... The pin slides within the upper column while the lower column remains stationary. At this point, the connecting rod rises, causing the lifting block to move upwards. Through the pushing surface, the inclined plane is pushed, squeezing the top block outwards. This causes the top block to extend and abut against the inner wall of the casing for secondary locking. Then, the pin moves to its limit, pulling the lower column and causing the retrieval tool to rise. The casing is pulled up by the friction between the steel pellets and the top block. During the upward displacement of the drill rod, the top block of the casing retrieval tool easily abuts against the inner wall of the casing. The greater the upward displacement of the connecting rod, the greater the clamping force on the retrieved casing.

[0012] As a further aspect of the present invention: multiple top blocks are provided and are evenly distributed on the surface of the salvaged component.

[0013] As a further aspect of the present invention, the steel particles are of an irregular shape.

[0014] Compared with the prior art, the present invention has the following advantages:

[0015] 1. In this invention, steel particles are sequentially conveyed through the insertion pipe, through the groove, and the steel particle hole to the space between the retrieval component and the casing. The steel particles accumulate between the retrieval component and the casing. At this time, the retrieval component rotates, squeezing and conveying the steel particles downwards. The steel particles are stuck in the spiral groove, increasing the friction between the retrieval component and the casing, which can effectively prevent the casing from falling off the retrieval component. It can provide a stable clamping effect for casing retrieval, effectively preventing or reducing casing slippage accidents during casing retrieval operations, ensuring construction results. The casing can be retrieved to the ground by lifting the drill rod. The operation is simple, the manufacturing is convenient, the operating cost is low, and it can effectively prevent the casing from falling off.

[0016] 2. In this invention, when the upper column is raised, the pin slides inside the upper column while the lower column remains stationary. At this time, the connecting rod rises, causing the lifting block to move upward. The pushing surface pushes the inclined plane, squeezing the top block outward and causing it to extend and abut against the inner wall of the casing for secondary locking. Then, the pin moves to its limit, the lower column is pulled, and the retrieval tool is raised. The casing is pulled up by the friction between the steel pellets and the top block. During the upward displacement of the drill rod, the top block of the casing retrieval tool easily abuts against the inner wall of the casing. The greater the upward displacement of the connecting rod, the greater the clamping force on the retrieved casing. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the working state of the present invention;

[0018] Figure 2 This is a schematic diagram of the salvage structure of the present invention;

[0019] Figure 3 This is a cross-sectional view of the salvage structure of the present invention;

[0020] Figure 4 This is a schematic diagram of the tensile state of the salvage structure of the present invention;

[0021] Figure 5 This is a schematic diagram of the cylindrical structure of the present invention;

[0022] Figure 6 For the present invention Figure 3 A magnified view of a portion of point A in the middle.

[0023] In the diagram: 1. Well wall; 2. Drill pipe; 3. Casing; 4. Steel pellets;

[0024] 5. Cylindrical body; 51. Upper cylinder; 52. Lower cylinder; 53. Male threaded connector; 54. Inserted pipe; 55. Through groove; 56. Steel pellet hole; 57. Pin; 58. Limiting groove; 59. Connecting rod;

[0025] 6. Salvage component; 61. Salvage head; 62. Spiral groove; 63. Top block; 64. Sliding groove; 65. Lifting block; 66. Inclined surface; 67. Pushing surface. Detailed Implementation

[0026] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0027] Please see Figure 1-6 The present invention provides a technical solution: a large-diameter engineering well casing precision retrieval device, including a cylindrical body 5 whose top end is connected to the bottom of the drill pipe 2 via a male threaded connector 53 and a retrieval component 6 connected to the male threaded connector 53 at the bottom of the cylindrical body 5. The retrieval component 6 is inserted into the inner cavity of the casing 3 inside the well wall 1. The cylindrical body 5 includes an upper column 51 and a lower column 52 that is slidably disposed in the upper column 51 via a pin 57. The inner cavity of the upper column 51 is provided with a limiting groove 58 for preventing the lower column 52 from falling off. The inner cavity of the lower column 52 is provided with a through groove 55 for conveying steel particles 4. The inner cavity of the upper column 51 is provided with an insertion pipe 54 that extends into the inner cavity of the through groove 55 for inserting steel particles 4. The bottom of the through groove 55 is provided with a steel particle hole 56 for discharging steel particles 4.

[0028] The retrieval component 6 includes a retrieval head 61, and the surface of the retrieval head 61 is provided with a spiral groove 62 adapted to the surface of the steel pellet 4. During the casing 3 retrieval operation, the casing 3 retrieval tool is connected to the drill pipe 2. The drill pipe 2 drives the cylinder 5 and the retrieval component 6 to rotate, and the casing 3 retrieval tool is lowered into the well wall 1 until it is inserted into the inner cavity of the casing 3, with the entire retrieval component 6 located in the inner cavity of the casing 3. After the retrieval component 6 is inserted into the inner cavity of the casing 3, the prepared steel pellet 4 is put into the drill pipe 2. The steel pellet 4 rolls from the steel pellet hole 56 on the retrieval device into the gap between the retrieval component 6 and the inner wall of the casing 3. The steel pellet 4 flows smoothly... The drill rod 2 is sequentially conveyed through the inner cavity, the insertion pipe 54, the through groove 55, and the steel pellet hole 56 to the space between the retrieval piece 6 and the casing 3. The steel pellets 4 accumulate between the retrieval piece 6 and the casing 3. At this time, the retrieval piece 6 rotates, squeezing and conveying the steel pellets 4 downwards. The steel pellets 4 are stuck in the spiral groove 62, increasing the friction between the retrieval piece 6 and the casing 3. This can effectively prevent the casing 3 from falling off the retrieval piece 6 and provide a stable clamping effect for the retrieval of the casing 3. This effectively prevents or reduces the occurrence of casing 3 slippage accidents during the retrieval operation, ensuring the construction results. The drill rod 2 can be lifted to retrieve the casing 3 to the ground.

[0029] The salvage component 6 is a rigid conical body with conical ends and a frustum in the middle. The maximum outer diameter of the frustum is 6-10 mm smaller than the inner diameter of the casing 3 to be salvaged.

[0030] The steel pellet hole 56 has a diameter of Ф20mm and is located at the bottom of the male threaded connector 53 at the bottom of the cylinder 5, with two holes.

[0031] The bottom frustum and cone of the salvage piece 6 have a protrusion at the connection point, and the distance between the outside of the protrusion and the inner wall of the sleeve 3 is less than the radius of the steel particle 4.

[0032] Both ends of the cylinder 5 are provided with male threaded connectors 53, and the top of the salvage piece 6 is provided with a female threaded connector that is threaded to the male threaded connectors 53.

[0033] The central truncated column of the salvage component 6 is designed to be larger at the top and smaller at the bottom. This design allows the steel particles 4 to accumulate at the bottom, making them less likely to fall off.

[0034] A top block 63 is slidably mounted on the inner cavity of the retrieval head 61 via a sliding groove 64. An inclined surface 66 is provided on one side of the top block 63. A lifting block 65 is slidably connected to the inner cavity of the retrieval component 6. A pushing surface 67, tangent to the surface of the inclined surface 66, is provided on the side of the lifting block 65. A connecting rod 59 is fixedly connected to the inner cavity of the upper column 51, passing sequentially through the pin 57 and the lower column 52 and extending into the inner cavity of the lower column 52. The bottom end of the connecting rod 59 is fixedly connected to the top of the lifting block 65. When the drill rod 2 is lifted, the upper column 51 is raised. When the upper column 51 rises, the pin 57 slides inside the upper column 51, while the lower column 52 remains stationary. At this time, the connecting rod 59 rises, causing the lifting block 65 to move upward. The pushing surface 67 pushes the inclined surface 66 to move, squeezing the top block 63 outward. This causes the top block 63 to extend and abut against the inner wall of the sleeve 3 for secondary locking. Then, the pin 57 moves to its limit, and the lower column 52 is pulled, causing the salvage piece 6 to rise. The friction between the steel pellets 4 and the top block 63 on the sleeve 3 pulls the sleeve 3 up.

[0035] Multiple top blocks 63 are provided and are evenly distributed on the surface of the salvage piece 6.

[0036] Steel pellet 4 has an irregular shape.

[0037] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A precision retrieval device for large-diameter engineering well casing, comprising a cylindrical body (5) whose top end is connected to the bottom of a drill pipe (2) via a male threaded connector (53) and a retrieval component (6) connected to the male threaded connector (53) at the bottom of the cylindrical body (5), wherein the retrieval component (6) is inserted into the inner cavity of the casing (3) within the well wall (1), characterized in that: The cylinder (5) includes an upper cylinder (51) and a lower cylinder (52) that slides within the upper cylinder (51) via a pin (57). The inner cavity of the upper cylinder (51) is provided with a limiting groove (58) to prevent the lower cylinder (52) from falling off. The inner cavity of the lower cylinder (52) is provided with a through groove (55) for conveying steel particles (4). The inner cavity of the upper cylinder (51) is provided with an insertion pipe (54) extending into the inner cavity of the through groove (55) for inserting steel particles (4). The bottom of the through groove (55) is provided with a steel particle hole (56) for discharging steel particles (4). The retrieval component (6) includes a retrieval head (61), and the surface of the retrieval head (61) is provided with a spiral groove (62) adapted to the surface of the steel pellet (4); the retrieval component (6) is a rigid cone, with cones at both ends and a frustum in the middle, the maximum outer diameter of the frustum being 10mm smaller than the inner diameter of the sleeve; the diameter of the steel pellet hole (56) is Ф20mm, and it is arranged at the last thread of the male threaded connector (53) at the bottom of the cylinder (5), and there are two of them; a protrusion is provided at the connection between the frustum and the cone at the bottom of the retrieval component (6), and the distance between the outside of the protrusion and the inner wall of the sleeve (3) is smaller than the radius of the steel pellet (4); both ends of the cylinder (5) are provided with male threaded connectors (53), and the top of the retrieval component (6) is provided with a female threaded connector that is threaded to the male threaded connector (53). The head; the middle truncated column of the salvage part (6) is set with a larger top and a smaller bottom; the inner cavity of the salvage head (61) is slidably provided with a top block (63) through a sliding groove (64), and a slope (66) is provided on one side of the top block (63). The inner cavity of the salvage part (6) is slidably connected with a lifting block (65). The side of the lifting block (65) is provided with a push surface (67) tangent to the surface of the slope (66). The inner cavity of the upper column (51) is fixedly connected with a connecting rod (59) that passes through the pin (57) and the lower column (52) in sequence and extends to the inner cavity of the lower column (52). The bottom end of the connecting rod (59) is fixedly connected to the top of the lifting block (65). There are multiple top blocks (63) and they are evenly distributed on the surface of the salvage part (6). The steel particles (4) are irregular in shape.

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