A tubing and casing fishing tool

Abstract

This invention relates to the field of oil and gas well completion and workover tools, and more particularly to a casing and tubing retrieval tool. The tool includes a housing with an upper variable thread connector at its left end, a first mandrel at the center of the housing, a mandrel seat at its left end, and a second mandrel at its right end, connected by a connecting cylinder. The outer wall of the left end of the first mandrel has a stationary sleeve and a stationary turbine blade, while the inner wall of the left end of the housing has a moving sleeve and a moving turbine blade. The right end of the first mandrel has a ball bearing, a tapered roller bearing, and a disc spring. The right end of the housing has outer cylinders A and B, and the right end of the second mandrel has a casing threading cutter head. A tubing retrieval device is also included. This tool is driven by working fluid pumped into the wellhead, eliminating the need for a rotary table and simplifying installation and operation. The casing threading cutter head has serrated blades on its outer wall, which can cut the inner wall of the casing to form a spiral groove for easy casing removal. The tubing retrieval device can clamp and pull the tubing to the bottom of the well during retrieval, achieving retrieval of both tubing and casing with a single tool.

Description

Technical Field

[0001] This invention relates to the field of oil and gas well completion and workover tools, and more particularly to an oil casing retrieval tool. Background Technology

[0002] Currently, in major workover and casing removal operations of oil and gas wells both domestically and internationally, mechanical internal cutting tools are typically used first. These tools are specifically designed to cut the casing from inside the downhole tubing string. Their working principle relies on the friction between friction blocks on the tool body and the inner wall of the casing. As the drill string rotates forward, this friction pushes the slips upward, thereby achieving the purpose of securing and anchoring the slips.

[0003] However, mechanical internal cutting tools have some significant drawbacks. When there is oil on the casing surface, the success rate of chuck mounting will be significantly reduced because the oil reduces friction, making it difficult for the chuck to anchor effectively. This tool requires a very high level of skill from the driller. Each drill can only be lowered slightly and cannot be lowered excessively. If the lowering is too small, an effective cutting force cannot be generated; if the lowering is too large, the tool will be damaged. The entire cutting process depends entirely on the cutting of the casing by the tool, so the requirements for the tool material are very high, requiring extremely high wear resistance and strength. During operation, the drill is also prone to jamming, which will not only cause the operation to be interrupted but may also cause secondary accidents. Judging whether the casing has been cut mainly relies on the torque, but due to human factors and equipment errors, misjudgment is inevitable, further increasing the operational risk.

[0004] In contrast, the mechanical external cutter employs a different design and working principle. It is a non-retractable tool that uses a clamping sleeve to hold the fish landing platform shoulder, and then lifts the drill string to provide the cutting force for the tool. It cuts the casing while rotating the tool. Since it cuts the external casing, it must be connected to the retrieval cylinder during operation. However, the retrieval cylinder is large and usually uses a thin-threaded connection, which makes tripping up and down the drill very inconvenient. The cutting position of the mechanical external cutter is limited by the casing coupling. The cutting force is provided by the driller lifting the drill string, and its magnitude is difficult to control precisely. Excessive cutting force will damage the tool, while insufficient cutting force will not allow for effective cutting. Summary of the Invention

[0005] (a) Technical problems to be solved This invention provides a tubing retrieval tool to overcome the problems of existing technologies that require the use of wellhead top drive or rotary table drive and high retrieval costs due to the installation of wellhead devices.

[0006] (II) Technical Solution To achieve the above objectives, the present invention provides an oil casing retrieval tool, comprising: a housing; The left end of the housing is provided with an upper buckle connector, and the housing is provided with a first outer cylinder and a second outer cylinder, with the first outer cylinder disposed in the second outer cylinder; The housing has a first mandrel at its center, a mandrel seat at the left end of the first mandrel, the mandrel seat being threadedly connected to the first mandrel, and a second mandrel at the right end of the first mandrel; A connecting cylinder is provided between the first mandrel and the second mandrel, with the left end of the connecting cylinder threaded to the first mandrel and the right end threaded to the second mandrel. The inner wall of the left end of the housing is provided with a moving sleeve and a moving turbine blade, and the outer wall of the left end of the first spindle is provided with a stationary sleeve and a stationary turbine blade. An annular mounting groove is provided between the outer wall of the right end of the first mandrel and the housing. The annular mounting groove contains a plurality of ball bearings, a plurality of tapered roller bearings, and a disc spring. The right end of the shell is provided with an outer cylinder A, the right end of the outer cylinder A is provided with a variable buckle connector, and the right end of the variable buckle connector is provided with an outer cylinder B; The outer wall of the right end of the second mandrel is fitted with a slip return spring, and the right end of the second mandrel is threadedly connected to a sleeve making cutter head, which is equipped with an oil pipe retrieval device.

[0007] Preferably, the housing is a hollow cylindrical structure, and the housing is threadedly connected to the upper variable thread connector.

[0008] Preferably, the moving turbine blade is fitted onto the outer wall of the stationary turbine blade, and the moving turbine blade meshes with the stationary turbine blade.

[0009] Preferably, the moving sleeve is disposed at the left end of the moving turbine blade, and the stationary sleeve is disposed at the left end of the stationary turbine blade.

[0010] Preferably, the disc spring is located at the right end of the annular mounting groove, and the plurality of ball bearings and the plurality of tapered roller bearings are arranged alternately at the left end of the disc spring.

[0011] Preferably, the outer cylinder A is a hollow cylindrical structure, and the left end of the outer cylinder A is provided with an inner step, which limits the movement of the disc spring.

[0012] Preferably, the sleeve-making cutter head has a hollow structure, and the outer wall of the sleeve-making cutter head is provided with annular serrated blades.

[0013] Preferably, the tubing retrieval device includes: a compression spring guide sleeve and a tension spring, wherein the compression spring guide sleeve is a hollow cylindrical structure, the compression spring guide sleeve is located at the right end of the second spindle, and a large-stroke compression spring is sleeved on the outer wall of the compression spring guide sleeve; The right end of the compression spring guide sleeve is provided with several expansion springs, which are arranged in a ring on the inner wall of the sleeve buckling cutter head, and the center of each expansion spring is provided with a circular through hole.

[0014] Preferably, the inner wall of the compression spring guide sleeve is provided with a buckle-making mechanism.

[0015] (III) Beneficial Effects This invention provides a casing retrieval tool that can be driven by working fluid pumped into the wellhead. Torque and drilling pressure are transmitted through a first and second mandrel, eliminating the need for a rotary table and reducing the installation process of the wellhead drive device. The casing threading cutter head has annular serrated blades on its outer wall. When the tool is used to retrieve casing, the rotating cutter head can cut spiral grooves into the inner wall of the casing. When the tool retracts, it can lift the casing to the bottom of the well, thus achieving casing retrieval. The retrieval operation utilizes several ball bearings, several tapered roller bearings, and disc springs to improve the transmission efficiency of the first mandrel and reduce vibration during transmission. The casing connection cutter head is equipped with a tubing retrieval device. When this retrieval tool is used to retrieve the tubing, the tubing extends into the casing connection cutter head, and the tubing retrieval device in the casing connection cutter head can hold the tubing in place. When the retrieval tool retracts, it can pull the tubing out of the well bottom, thus achieving the retrieval operation of the tubing. This allows for the completion of both tubing and casing retrieval using a single tool. Attached Figure Description

[0016] Figure 1 This diagram illustrates the structure of a casing retrieval tool according to the present invention. Figure 2 Show Figure 1 Partial schematic diagram of section A; Figure 3 Show Figure 1 Partial schematic diagram of C; Figure 4 Show Figure 1 Partial schematic diagram of section B.

[0017] Wherein: 1: Upper variable thread connector; 2: Mandrel seat; 3: First outer cylinder; 4: Second outer cylinder; 5: Moving sleeve; 6: Stationary sleeve; 7: Stationary turbine blade; 8: Moving turbine blade; 9: First mandrel; 10: Housing; 11: Ball bearing; 12: Tapered roller bearing; 13: Disc spring; 14: Outer cylinder A; 15: Connecting cylinder; 16: Variable thread connector; 17: Second mandrel; 18: Outer cylinder B; 19: Large stroke compression spring; 20: Slip return compression spring; 21: Compression spring guide sleeve; 22: Expansion spring; 23: Sleeve thread-making cutter head. Detailed Implementation

[0018] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. The technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] In the description of this invention, it is necessary to understand that the orientations or positional relationships indicated by terms such as "upper," "lower," "left," "right," "inner," "outer," "top," and "bottom" are based on the orientations or positional relationships shown in the accompanying drawings. They are intended only to facilitate the description of this invention and to simplify the description, and are not intended to indicate or imply that the components 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 invention.

[0020] like Figure 1-4 As shown, the present invention provides an oil casing retrieval tool, comprising: a housing 10; The housing 10 has an upper variable coupling 1 at its left end, and the housing 10 is threadedly connected to the upper variable coupling 1. The housing 10 has a first spindle 9 at its center, and a spindle seat 2 at its left end, which is threadedly connected to the first spindle 9. The first spindle 9 has a second spindle 17 at its right end, and a connecting cylinder 15 is provided between the first spindle 9 and the second spindle 17. The left end of the connecting cylinder 15 is threadedly connected to the first spindle 9, and the right end is threadedly connected to the second spindle 17. The first spindle 9 and the second spindle 17 are used to transmit torque.

[0021] The housing 10 is provided with a first outer cylinder 3 and a second outer cylinder 4. The first outer cylinder 3 is located inside the second outer cylinder 4. The first outer cylinder 3 and the second outer cylinder 4 are located on the outer wall of the first mandrel 9. The inner wall of the left end of the housing 10 is provided with a moving sleeve 5 and a moving turbine blade 8. The moving sleeve 5 is located at the left end of the moving turbine blade 8. The outer wall of the left end of the first mandrel 9 is provided with a stationary sleeve 6 and a stationary turbine blade 7. The stationary sleeve 6 is located at the left end of the stationary turbine blade 7. The moving turbine blade 8 is sleeved on the outer wall of the stationary turbine blade 7. The moving turbine blade 8 and the stationary turbine blade 7 mesh with each other. The stationary turbine blade 7 and the moving turbine blade 8 form a drive turbine assembly. The drive turbine assembly can rotate under the drive of the high-pressure working fluid at the wellhead. The moving turbine blade 8 can drive the stationary turbine blade 7 installed on the outer wall of the first mandrel 7 to rotate. The rotation of the static turbine blade 7 can be transmitted to the second spindle 17 through the first spindle 9, thus realizing the transmission of torque.

[0022] The housing 10 is provided with a first outer cylinder 3 and a second outer cylinder 4. The first outer cylinder 3 is disposed in the second outer cylinder 4. The first outer cylinder 3, the second outer cylinder 4, the stationary sleeve 6, and the moving sleeve 5 limit the drive turbine assembly. An annular mounting groove is provided between the outer wall of the right end of the first spindle 9 and the housing 10. The annular mounting groove is located on the right side of the drive turbine assembly. A plurality of ball bearings 11, a plurality of tapered roller bearings 12 and a disc spring 13 are provided in the annular mounting groove. The disc spring 13 is located at the right end of the annular mounting groove. The plurality of ball bearings 11 and the plurality of tapered roller bearings 12 are arranged alternately at the left end of the disc spring 13. It should be noted that in actual operation, nine ball bearings 11 and two tapered roller bearings 12 are usually used. The three ball bearings 11 are located at the left end, the two tapered roller bearings 12 are in the middle, and the six ball bearings 11 are located at the right end. The staggered arrangement of these ball bearings 11 and tapered roller bearings 12 can effectively reduce the friction of the first spindle 9 during rotation and improve the transmission efficiency. The disc spring 13 is used to buffer the vibration of the first spindle 9 during transmission and reduce the wear and damage of the equipment.

[0023] The housing 10 has an outer cylinder A14 at its right end, a variable buckle connector 16 at its right end, and an outer cylinder B18 at its right end. The outer cylinder A14 is a hollow cylindrical structure. The outer cylinder A14 has an inner step at its left end. The step limits the disc spring 13 to prevent it from shifting during operation. The outer cylinder B18 is used to protect the second spindle 17 from damage during operation.

[0024] The outer wall of the right end of the second mandrel 17 is fitted with a slip return spring 20. The right end of the second mandrel 17 is threadedly connected to the casing threading cutter head 23. The casing threading cutter head 23 is a hollow structure. The outer wall of the casing threading cutter head 23 is provided with annular serrated blades. When the casing is being retrieved, the annular serrated blades can be rotated to cut spiral grooves on the inner wall of the casing. When the retrieval tool retracts, the casing can be pulled out of the well bottom to realize the casing retrieval operation.

[0025] The casing buckle-making cutter head 23 is equipped with a tubing retrieval device, a compression spring guide sleeve 21 and a tension spring 22. The compression spring guide sleeve 21 is a hollow cylindrical structure. The compression spring guide sleeve 21 is located at the right end of the second spindle 17. A large-stroke compression spring 19 is sleeved on the outer wall of the compression spring guide sleeve 21. Several tension springs 22 are provided at the right end of the compression spring guide sleeve 21. The several tension springs 22 are arranged in a ring on the inner wall of the casing buckle-making cutter head 23. A circular through hole is provided at the center of the several tension springs 22. The buckle-making mechanism is provided on the inner wall of the compression spring guide sleeve 21. The long-stroke compression spring 19 serves as a buffer to prevent damage to the spring 22 due to sudden pressure. When this retrieval tool is used to retrieve tubing, the tubing is inserted into the casing coupling cutter head 23. Under pressure, the tubing applies pressure to the expansion spring 22, causing the expansion spring 22 to open and enter the casing coupling cutter head 23. The expansion spring 22 is used to limit the tubing entering the casing coupling cutter head 23. After the tubing extends a certain distance, it enters the compression spring guide sleeve 21. The inner wall of the compression spring guide sleeve 21 is provided with a coupling mechanism, which rotates the outer wall of the tubing to create a coupling, so that the tubing is fixed in the compression spring guide sleeve 21. When the retrieval tool retracts, the tubing can be pulled out of the well bottom to realize the retrieval operation of the tubing.

[0026] The following is a detailed description of the actual working scenario of an oil casing salvage tool.

[0027] The oil casing retrieval tool includes the following steps in actual operation: Step S1: After the casing and tubing retrieval tool is fully connected, it is slowly lowered to the bottom of the well to approach the target casing or tubing. In step S2, high-pressure working fluid is injected through the wellhead to drive the turbine assembly to start rotating. The moving turbine blade 8 rotates under the drive of the high-pressure working fluid, and drives the stationary turbine blade 7 to rotate through meshing with the stationary turbine blade 7; In step S3, the rotation of the stationary turbine blade 7 is transmitted to the second mandrel 17 through the first mandrel 9, and finally to the sleeve forming cutter head 23.

[0028] When retrieving the casing: the annular serrated blade on the outer wall of the casing threading cutter head 23 can cut a spiral groove on the inner wall of the casing during rotation. This spiral groove can effectively fix the casing, so that it can be smoothly pulled out of the well bottom when the retrieval tool retracts. When retrieving the tubing: the tubing is inserted into the casing coupling cutter head 23. Under pressure, the tubing applies pressure to the expansion spring 22, causing the expansion spring 22 to open. After the tubing extends a certain distance, it enters the compression spring guide sleeve 21. The coupling mechanism on the inner wall of the compression spring guide sleeve 21 rotates and couples the outer wall of the tubing, thus fixing the tubing in the compression spring guide sleeve 21.

[0029] When the salvage tool retracts, the slip return spring 20 helps the slip return to its original position, reducing vibration and damage to the equipment.

[0030] It is understood that the various embodiments mentioned above in this invention can be combined with each other to form combined embodiments without violating the principle and logic. Due to space limitations, this invention will not elaborate further.

[0031] Those skilled in the art will understand that, in the above-described method of the specific implementation, the order in which each step is written does not imply a strict execution order and does not constitute any limitation on the implementation process. The specific execution order of each step should be determined by its function and possible internal logic.

[0032] The present invention provides an oil casing retrieval tool that is driven to rotate by working fluid pumped into the wellhead. Torque and drilling pressure are transmitted through the first mandrel 9 and the second mandrel 17, eliminating the need for a rotary table and reducing the installation process of the wellhead drive device. The outer wall of the casing threading cutter head 23 is provided with annular serrated blades. When the retrieval tool is used to retrieve casing, the casing threading cutter head 23 can be rotated to cut spiral grooves on the inner wall of the casing. When the retrieval tool retracts, it can lift the casing to the bottom of the well to achieve the casing retrieval operation. The ball bearings 11, tapered roller bearings 12, and disc springs 13 are used to improve the transmission efficiency of the first mandrel 9 and reduce vibration during transmission. The casing connection cutter head 23 is equipped with a tubing retrieval device. When the retrieval tool is used to retrieve the tubing, the tubing extends into the casing connection cutter head, and the tubing retrieval device in the casing connection cutter head 23 can hold the tubing in place. When the retrieval tool retracts, it can pull the tubing out of the well bottom to achieve the retrieval operation of the tubing, thereby achieving the purpose of completing the retrieval of the tubing and casing using a single tool.

[0033] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A tool for retrieving oil casing, characterized in that, include: Shell (10); The left end of the housing (10) is provided with an upper buckle connector (1), and the housing (10) is provided with a first outer cylinder (3) and a second outer cylinder (4), with the first outer cylinder (3) located in the second outer cylinder (4); The housing (10) has a first spindle (9) at its center, a spindle seat (2) at the left end of the first spindle (9), the spindle seat (2) is threadedly connected to the first spindle (9), and a second spindle (17) at the right end of the first spindle (9). A connecting sleeve (15) is provided between the first mandrel (9) and the second mandrel (17). The left end of the connecting sleeve (15) is threaded to the first mandrel (9) and the right end is threaded to the second mandrel (17). The inner wall of the left end of the housing (10) is provided with a moving sleeve (5) and a moving turbine blade (8), and the outer wall of the left end of the first spindle (9) is provided with a stationary sleeve (6) and a stationary turbine blade (7). An annular mounting groove is provided between the outer wall of the right end of the first mandrel (9) and the housing (10). The annular mounting groove contains a plurality of ball bearings (11), a plurality of tapered roller bearings (12), and a disc spring (13). The shell (10) is provided with an outer cylinder A (14) at the right end, the outer cylinder A (14) is provided with a variable buckle connector (16) at the right end, and the variable buckle connector (16) is provided with an outer cylinder B (18) at the right end. The outer wall of the right end of the second mandrel (17) is fitted with a slip return spring (20), and the right end of the second mandrel (17) is threadedly connected to a casing buckle cutter head (23), which is equipped with a tubing retrieval device.

2. The casing retrieval tool according to claim 1, characterized in that, The housing (10) is a hollow cylindrical structure, and the housing (10) is threadedly connected to the upper variable snap connector (1).

3. The casing retrieval tool according to claim 1, characterized in that, The moving turbine blade (8) is fitted on the outer wall of the stationary turbine blade (7), and the moving turbine blade (8) meshes with the stationary turbine blade (7).

4. The casing retrieval tool according to claim 1, characterized in that, The moving sleeve (5) is located at the left end of the moving turbine blade (8), and the stationary sleeve (6) is located at the left end of the stationary turbine blade (7).

5. The casing retrieval tool according to claim 1, characterized in that, The disc spring (13) is located at the right end of the annular mounting groove, and the plurality of ball bearings (11) and the plurality of tapered roller bearings (12) are arranged alternately at the left end of the disc spring (13).

6. The casing retrieval tool according to claim 5, characterized in that, The outer cylinder A (14) is a hollow cylindrical structure. The left end of the outer cylinder A (14) is provided with an inner step, which limits the disc spring (13).

7. The casing retrieval tool according to claim 1, characterized in that, The sleeve fastening cutter head (23) has a hollow structure, and the outer wall of the sleeve fastening cutter head (23) is provided with annular serrated blades.

8. The casing retrieval tool according to claim 7, characterized in that, The oil pipe retrieval device includes: a compression spring guide sleeve (21) and a spring (22). The compression spring guide sleeve (21) is a hollow cylindrical structure. The compression spring guide sleeve (21) is located at the right end of the second spindle (17). A large stroke compression spring (19) is sleeved on the outer wall of the compression spring guide sleeve (21). The right end of the compression spring guide sleeve (21) is provided with several expansion springs (22), which are arranged in a ring on the inner wall of the sleeve buckle cutter head (23). The center of each expansion spring (22) is provided with a circular through hole.

9. The casing retrieval tool according to claim 8, characterized in that, The inner wall of the compression spring guide sleeve (21) is provided with a buckle-making mechanism.

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