Composite overshot for small fallen objects

Abstract

The invention relates to the technical field of well cementation of petroleum and natural gas wells, in particular to a composite fishing barrel for small fallen objects, and aims to solve the problem that an existing fishing tool cannot effectively fish the small fallen objects. The device comprises a sleeve and a collecting assembly, the collecting assembly is arranged in the sleeve and has an open state and a closed state; in the open state, fluid flows from the lower portion of the sleeve to the upper portion of the sleeve, and small falling objects move upwards along with the fluid. And in the closed state, the small falling objects are stored above the collecting assembly. When the fluid flows upwards from the lower part of the sleeve, the small falling objects are driven to move upwards along with the fluid; after operation is carried out for a period of time, the pipe string is lifted, the collecting assembly is automatically closed after fluid pressure disappears, and it is ensured that the small falling objects are stored in the collecting assembly and cannot fall to the well bottom again. According to the scheme, the collecting efficiency of small falling objects is improved, risks in the salvage process are reduced through reasonable design, and salvage operation is safer and more efficient.

Description

Technical Field

[0001] This invention relates to the field of cementing technology for oil and gas wells, and in particular to a composite retrieval tube for small debris. Background Technology

[0002] In actual oil and water well operations, due to the complexity of the downhole working environment and uncontrollable factors during operation, small items such as rubber, nuts, and bolts often fall to the bottom of the well. Although these objects are small in size, once they fall to the bottom of the well, they may cause serious equipment damage or operational malfunctions, especially significantly increasing the incidence of pump sticking, thereby affecting the normal production and operation of the oil well.

[0003] Currently, commonly used retrieval tools on the market mainly include pump rod composite retrieval tubes and soft object retrieval tools. However, these tools have revealed some significant shortcomings in practical applications. Pump rod composite retrieval tubes are primarily used for retrieving larger rod-shaped objects, and their design is based on the principles of retrieving large objects. However, for smaller objects, their retrieval efficiency is low, operation is difficult, and their applicability is greatly limited, making them unable to flexibly handle a variety of small object situations. Furthermore, these tools are relatively large in size and structure, requiring more space and more complex operating procedures, increasing the complexity and difficulty of downhole operations.

[0004] On the other hand, soft-feature retrieval tools use a guide shoe at the bottom of the retrieval cylinder, along with a retrieval auger and strong magnetic blocks, to attract small steel items. While this tool can effectively reduce retrieval costs and operational intensity in certain situations, its design also has significant shortcomings. During the lifting of the tubing string, the tool's design fails to adequately consider the stability of small objects, causing them to easily detach from the retrieval tool and fall back to the bottom of the well when subjected to external vibrations, ultimately affecting the overall retrieval effect. This instability not only reduces the success rate of retrieval but also increases the time cost and risk of the operation.

[0005] In summary, existing retrieval tools have significant limitations and defects in dealing with small falling objects, and there is an urgent need to improve the adaptability and operational stability of the tools through technological improvements, thereby ensuring the safety and efficiency of downhole operations. Summary of the Invention

[0006] This invention provides a composite retrieval tube for small objects to alleviate the problem that existing retrieval tools cannot effectively retrieve small objects.

[0007] To alleviate the above-mentioned technical problems, the technical solution provided by the present invention is as follows:

[0008] This invention provides a composite retrieval tube for small objects falling into the air, comprising a sleeve and a collection assembly;

[0009] The collection component is located inside the sleeve and has an open and closed state;

[0010] When open, fluid flows from the lower part of the sleeve to the upper part of the sleeve channel, and small objects fall upward with the fluid.

[0011] When the device is off, small items are stored above the collection component.

[0012] Furthermore,

[0013] The collection components include a fixed plate and a flip plate;

[0014] One end of the fixed plate is fixedly connected to the sleeve, and the other end is rotatably connected to the flap.

[0015] The end of the flap away from the fixed plate is movably connected to the sleeve.

[0016] Furthermore,

[0017] The fixing plate and the flip plate are semicircles of the same size;

[0018] The fixing plate and the flap are respectively installed horizontally inside the sleeve.

[0019] Furthermore,

[0020] A pivot is provided at the connection between the fixed plate and the flip plate.

[0021] Furthermore,

[0022] The collection components also include torsion springs;

[0023] The torsion spring always has the ability to drive the flap to rotate counterclockwise.

[0024] Furthermore,

[0025] The elastic restoring force of the torsion spring is less than the pressure exerted on the flapper when the fluid flows upward.

[0026] Furthermore,

[0027] The flap can be rotated up to a position parallel to the axis of the sleeve.

[0028] Furthermore,

[0029] It also includes strong magnetic blocks;

[0030] Multiple strong magnetic blocks are arranged in a ring array on the inner wall of the sleeve below the collecting component.

[0031] The beneficial effects of the composite retrieval cylinder for small objects in this invention are analyzed as follows:

[0032] This device, through the cooperation of the casing and the collection assembly, forms an automatically adjustable retrieval system under water pressure. When the collection assembly is open, fluid flows upward from the lower part of the casing, carrying small objects upward. After a period of operation, the casing is pulled up, and the collection assembly automatically closes after the fluid pressure disappears, ensuring that the small objects are stored within the collection assembly and do not fall back to the bottom of the well. This solution not only improves the collection efficiency of small objects but also reduces the risks during the retrieval process through reasonable design, making the retrieval operation safer and more efficient. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of the present invention, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0034] Figure 1 A schematic diagram of the device in the off state of the collection components;

[0035] Figure 2 A schematic diagram of the device with the collection components in the open state;

[0036] Figure 3 A top-view structural diagram of the collection components;

[0037] Figure 4 This is a schematic diagram of the installation of a strong magnetic block.

[0038] icon:

[0039] 100-sleeve;

[0040] 200 - Collection component; 210 - Fixing plate; 220 - Flip plate; 230 - Torsion spring; 240 - Strong magnetic block. Detailed Implementation

[0041] Because existing soft-tipped object retrieval tools have poor stability when lifting the tubing string, small objects are prone to detaching from the retrieval tool and falling back to the bottom of the well when subjected to external vibrations, ultimately affecting the effectiveness of the retrieval operation. This instability not only reduces the success rate of retrieval but also increases the time cost and risk of the operation.

[0042] In view of this, such as Figures 1 to 4 The present solution provides a composite retrieval cylinder for small falling objects to alleviate the above-mentioned problems.

[0043] This device includes a sleeve 100 and a collection assembly 200;

[0044] The collecting component 200 is disposed within the sleeve 100 and has an open state and a closed state;

[0045] When open, fluid flows from the lower part of sleeve 100 to the upper part of sleeve 100, and small objects fall upward with the fluid.

[0046] When closed, small items are stored above the collection component 200.

[0047] The upper end of this device is connected to a cement truck via a pipe string. The device is then vertically inserted into the well to be retrieved. Since there is always a certain height of cement slurry in the well, the collecting component 200 is in the open state due to water pressure during the insertion of the device. The cement truck continuously sucks up the liquid in the pipe string from the ground. At the same time, water is continuously injected into the well along the annulus between the pipe string and the well wall, so that the liquid in the well is always drawn to the ground along the casing 100. The movement of the liquid carries small objects that have fallen into the well into the casing 100. After the operation has been going on for a period of time, the pipe string is pulled up, and the fluid pressure on the collecting component 200 disappears, causing it to enter the closed state. This prevents small objects from falling back to the bottom of the well from the casing 100, ensuring the stable collection of small objects during the retrieval process, avoiding objects falling back, and significantly improving the success rate of retrieval.

[0048] Regarding the shape and structure of the collection component 200, such as Figure 1 , Figure 2 and Figure 3 As shown:

[0049] The collecting component 200 includes a fixing plate 210 and a flip plate 220;

[0050] One end of the fixing plate 210 is fixedly connected to the sleeve 100, and the other end is rotatably connected to the flap 220;

[0051] The end of the flap 220 away from the fixed plate 210 is movably connected to the sleeve 100.

[0052] Specifically, the fixed plate 210 is a closed structure and remains closed regardless of the pressure of the liquid flow; the flap 220 is a movable structure that opens after being impacted by the liquid flow, causing the collection component 200 to enter the open state.

[0053] In this design, the fixing plate 210 and the flip plate 220 are semicircles of the same size;

[0054] The fixing plate 210 and the flap 220 are respectively installed in the sleeve 100 in the horizontal direction.

[0055] Specifically, when the collecting component 200 is closed, the fixing plate 210 and the flap 220 are horizontally connected to form a complete circle that matches the inner wall of the sleeve 100, so as to completely seal the sleeve 100 and minimize the risk of small objects falling out of the gap when the device is taken out by lifting the tube string.

[0056] In this design, a pivot is provided at the connection between the fixed plate 210 and the flip plate 220.

[0057] In order to ensure that the movable connection between the flap 220 and the sleeve 100 can always maintain tight contact and completely seal the sleeve 100 after the collection component 200 enters the closed state, the collection component 200 also includes a torsion spring 230.

[0058] The torsion spring 230 always has the ability to drive the flap 220 to rotate counterclockwise. One end of the torsion spring 230 is fixedly connected to the fixed plate 210, and the other end is fixedly connected to the flap 220. After the pipe string is lifted and the fluid pressure on the flap 220 is reduced, the torsion spring 230 can quickly drive the flap 220 to rotate counterclockwise to close the casing 100, thus minimizing the risk of small objects falling back to the bottom of the well inside the casing 100.

[0059] In this scheme, the elastic restoring force of the torsion spring 230 is less than the pressure on the flap 220 when the fluid flows upward. The model of the torsion spring 230 should be selected according to the power of the cement truck to avoid abnormal shutdown of the collection component 200 during the extraction process due to insufficient extraction power of the cement truck.

[0060] Preferably, the flap 220 is rotated to a position parallel to the axis of the sleeve 100. In order to prevent the flap 220 from opening too quickly or being subjected to too much fluid pressure, which could cause the flap 220 to open too much and damage the torsion spring 230, or cause a large number of small objects to fall and be squeezed on the upper part of the flap 230 after excessive folding, thus affecting the collection component 200 to enter the closed state and resulting in retrieval failure, a limit is set on the rotating shaft (not shown due to the closed view) so that the flap 220 is opened to a vertical state at most.

[0061] This solution also includes a strong magnetic block 240;

[0062] Multiple strong magnetic blocks 240 are arranged in a ring on the inner wall of the sleeve 100 below the collecting component 200.

[0063] Specifically, the small objects falling into the well include non-metallic and metallic objects. Non-metallic objects are lighter and more easily carried into the casing 100 by the flow of liquid, while metallic objects tend to fall back down on their own after rising a certain distance. Therefore, strong magnetic blocks 240 are arranged in a ring on the inner wall of the casing 100 so that the metallic objects entering the casing 100 can be attracted by the strong magnetic blocks 240 and then carried out of the well bottom along with this device.

[0064] This solution has at least the following beneficial effects:

[0065] Existing retrieval tools suffer from poor stability when small objects fall during the lifting of the tubing string, making them prone to detachment under external vibrations, thus introducing unnecessary risks and costs to the retrieval operation. This solution introduces a composite retrieval cylinder for small objects, aiming to effectively address this problem.

[0066] This device, through the cooperation of casing 100 and collection assembly 200, forms a retrieval system that can automatically adjust under water pressure. When collection assembly 200 is in the open state, fluid flows upward from the lower part of casing 100, carrying small objects upward. After the operation has been running for a period of time, the casing string is pulled up, and collection assembly 200 automatically closes after the fluid pressure disappears, ensuring that small objects are stored in the collection assembly and will not fall back to the bottom of the well. This solution not only improves the collection efficiency of small objects but also reduces the risks during the retrieval process through reasonable design, making the retrieval operation safer and more efficient.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A composite scooping tube for small objects falling from the ground, characterized in that: Includes a sleeve (100) and a collection assembly (200); The collecting component (200) is disposed inside the sleeve (100) and has an open state and a closed state; In the open state, fluid flows from the lower part of the sleeve (100) to the upper part of the sleeve (100), and small objects fall upward with the fluid; In the closed state, the small objects are stored above the collection assembly (200).

2. The composite retrieval cylinder for small objects as described in claim 1, characterized in that: The collection component (200) includes a fixing plate (210) and a flap (220); One end of the fixing plate (210) is fixedly connected to the sleeve (100), and the other end is rotatably connected to the flap (220); The end of the flap (220) away from the fixed plate (210) is movably connected to the sleeve (100).

3. The composite retrieval cylinder for small objects as described in claim 2, characterized in that: The fixing plate (210) and the flip plate (220) are semicircles of the same size; The fixing plate (210) and the flap (220) are respectively arranged horizontally inside the sleeve (100).

4. The composite retrieval cylinder for small objects as described in claim 3, characterized in that: A pivot is provided at the connection between the fixed plate (210) and the flip plate (220).

5. The composite retrieval cylinder for small objects as described in claim 4, characterized in that: The collecting assembly (200) also includes a torsion spring (230); The torsion spring (230) always has the ability to drive the flap (220) to rotate counterclockwise.

6. The composite retrieval cylinder for small objects as described in claim 5, characterized in that: The elastic restoring force of the torsion spring (230) is less than the pressure exerted on the flap (220) when the fluid flows upward.

7. The composite retrieval cylinder for small objects according to claim 6, characterized in that: The flap (220) can rotate to a position parallel to the axis of the sleeve (100) at most.

8. The composite retrieval cylinder for small objects according to claim 7, characterized in that: It also includes a strong magnetic block (240); Multiple strong magnetic blocks (240) are arranged in a ring on the inner wall of the sleeve (100) below the collecting assembly (200).

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