Segmented pipe expanding tool

Abstract

The invention provides a sectioning pipe expanding tool which comprises a connector, a mandrel and an expanding sleeve, and belongs to the technical field of petroleum downhole operation. The mandrel comprises a first part, a second part and a third part which are sequentially connected, the connector is connected with the first part, and the second part forms a conical surface. A limiting surface is formed at the joint of the second part and the first part. The expansion sleeve is arranged on the outer side of the mandrel in a sleeving mode and comprises a straight pipe and a taper pipe, the taper pipe is matched with the conical face in shape, and a limiting block capable of abutting against the limiting face is arranged at the end, away from the taper pipe, of the straight pipe. A plurality of sectioning grooves distributed at intervals in the circumferential direction are formed in the taper pipe in the axis direction, and the expansion sleeve is divided into a plurality of sectioning pieces through the sectioning grooves. The mandrel can move in the expansion sleeve, the end, away from the mandrel, of the connector is connected with a driving assembly, and the driving assembly is used for pushing the mandrel to move and opening the multiple sectioning pieces so as to expand the expansion sleeve. The problems that an existing pipe expanding tool is prone to damage and short in service life are solved.

Description

Technical Field

[0001] This application relates to the field of oil well downhole operation technology, and more specifically, to a segmented tubing expansion tool. Background Technology

[0002] In the complex downhole operating environment, casing is constantly subjected to the severe test of dynamically changing formation pressure and internal and external fluid compression. As oilfield development progresses, significant changes in formation stress and fluid pressure lead to a sharp increase in the external stress borne by the casing. Coupled with frequent high-intensity operations such as high-pressure water injection, fracturing, and perforation completion, the operating environment of the casing further deteriorates, and casing deformation becomes a common problem, posing a major challenge to the efficient development of the oilfield.

[0003] Casing deformation not only directly reduces the internal passage, making it difficult to smoothly run conventional downhole tools, but also seriously hinders the normal production operations of oil and water wells, damages the integrity of the injection and production well network, and has a profound and adverse impact on the overall development effect and economic benefits of the oilfield.

[0004] Currently, there are tube expansion tools on the market such as eccentric roller shapers, three-cone roller shapers, and hydraulic ball bearing shapers. However, in practical applications, these tools generally face problems such as easy damage to rollers or balls, high risk of detachment, difficulty in fully restoring the original diameter of the sleeve, long operation cycle, and short service life. Summary of the Invention

[0005] This application aims to provide a segmented tube expander tool, which solves the problems of easy damage and short service life of existing tube expanders.

[0006] This application provides a segmented tube expansion tool, comprising: at least one tube expansion mechanism; the tube expansion mechanism includes a connector, a mandrel, and an expansion sleeve;

[0007] The mandrel includes a first part, a second part, and a third part connected in sequence. The connector is connected to the first part. The diameter of the second part gradually decreases from the end connected to the first part to the end connected to the third part to form a conical surface.

[0008] Furthermore, the diameter of the end of the second part that connects to the first part is larger than the diameter of the first part, so as to form a limiting surface;

[0009] The expansion sleeve is fitted on the outside of the mandrel. The expansion sleeve includes a straight tube and a tapered tube connected to each other. The shape of the tapered tube matches the conical surface. The end of the straight tube away from the tapered tube is provided with a limiting block that can abut against the limiting surface.

[0010] The tapered tube has multiple segmented grooves arranged at intervals in the circumferential direction along the axial direction. The segmented grooves extend towards the straight tube to the limiting block to divide the expansion sleeve into multiple segmented pieces.

[0011] The mandrel is movable within the expansion sleeve. The end of the connector away from the mandrel is connected to a drive assembly, which is used to push the mandrel to move and expand the multiple segments, thereby expanding the expansion sleeve.

[0012] Optionally, the drive assembly includes a multi-stage hydraulic anchor and a multi-stage hydraulic booster;

[0013] The multi-stage hydraulic booster is connected to the end of the connector away from the spindle, and the multi-stage hydraulic anchor is connected to the end of the multi-stage hydraulic booster away from the connector.

[0014] An oil pipe is connected to the end of the multi-stage hydraulic anchor that is away from the multi-stage hydraulic booster.

[0015] Optionally, each of the segmented pieces has multiple arc-shaped protrusions on its inner and outer surfaces along the axial direction of the expansion sleeve, and the arc-shaped protrusions on the inner surface correspond one-to-one with the arc-shaped protrusions on the outer surface.

[0016] Optionally, the spacing between the arc-shaped protrusions is 40mm-80mm.

[0017] Optionally, the end of the third part is threaded with a guide body, and a reset component is provided on the outside of the third part. The reset component is used to ensure that the expansion sleeve will not slip onto the third part when the expansion tube mechanism is lowered into the well.

[0018] Optionally, the reset assembly includes a spring seat and a spring;

[0019] The spring seat and one end of the spring are fixedly connected. The spring seat is located close to the conical surface, and the inner diameter of the spring seat is smaller than the outer diameter of the conical surface. The other end of the spring abuts against the guide body.

[0020] Optionally, the side of the guide away from the mandrel is configured as a spherical surface.

[0021] Optionally, the split tube expander includes two sets of tube expander mechanisms, namely a first tube expander mechanism and a second tube expander mechanism.

[0022] The first tube expansion mechanism and the second tube expansion mechanism are connected by the connector in the second tube expansion mechanism, and the connector in the first tube expansion mechanism is connected to the drive assembly.

[0023] Optionally, the mandrel diameter of the first tube expansion mechanism is larger than the mandrel diameter of the second tube expansion mechanism.

[0024] Optionally, the taper of the second part is set to 1:10.

[0025] Beneficial effects:

[0026] 1. Integrated high-strength material design: In this invention, the rolling element (arc-shaped protrusion) and the expansion sleeve are cleverly integrated into one piece and carefully crafted with high-strength materials. This design fundamentally eliminates the risk of the rolling element falling off, greatly extends the service life, and significantly enhances the strength and stability during the expansion process.

[0027] 2. Flexible retraction split expansion sleeve structure: The unique split expansion sleeve design allows it to smoothly disengage as the mandrel is retracted, effectively preventing the tool from being accidentally jammed during operation and improving the safety and efficiency of the operation.

[0028] 3. Excellent circumferential continuity of the expansion surface: This invention ensures the continuity and smoothness of the expansion surface in the circumferential direction. This characteristic is crucial for ensuring the roundness of the inner diameter after shaping, thereby achieving a more precise and efficient shaping effect and meeting higher engineering standards.

[0029] 4. Serial application capability of serialized multi-stage split tube expansion tools: Through innovative serialized design, the multi-stage split tube expansion tools of this invention can be flexibly used in series. This function greatly improves the efficiency and flexibility of tube shaping, enabling complex and ever-changing engineering tasks to be completed more quickly and accurately. Attached Figure Description

[0030] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the tube expansion mechanism of a segmented tube expansion tool according to an embodiment of this application;

[0032] Figure 2 yes Figure 1 Schematic diagram of the cross-sectional structure at point AA;

[0033] Figure 3 yes Figure 1 Schematic diagram of the cross-sectional structure at point BB;

[0034] Figure 4This is a schematic diagram of a split tube expansion tool in a sleeve according to an embodiment of this application;

[0035] Figure 5 This is a schematic diagram of the structure of a split tube expander tool including two tube expander mechanisms according to an embodiment of this application;

[0036] Explanation of reference numerals in the attached drawings: Connector 1, Mandrel 2, First part 21, Second part 22, Third part 23, Limiting surface 24, Conical surface 25, Expansion sleeve 3, Straight tube 31, Conical tube 32, Limiting block 33, Split groove 34, Split piece 35, Arc-shaped protrusion 36, Spring seat 4, Spring 5, Guide body 6, Oil pipe 7, Multi-stage hydraulic anchor 8, Multi-stage hydraulic booster 9, Sleeve 11, First expansion tube mechanism 12, Second expansion tube mechanism 13. Detailed Implementation

[0037] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0038] In related technologies, eccentric roller shapers are devices used for pipe bending, elbowing, tees, and fan-shaped compensation fabrication; they are also known as arched eccentric roller shapers. They mainly consist of multiple eccentric wheels of different diameters, with the gap between the wheels called a wall thickness adjustment groove. The sleeve is placed into the wall thickness adjustment groove, and the shape of the sleeve is changed by adjusting the eccentric rollers. However, because the eccentric roller shaper needs to bend the sleeve during operation, the rollers may be subjected to significant pressure and wear, leading to brittleness or damage. This not only affects the service life of the shaper but may also damage the sleeve.

[0039] The three-cone roller shaper mainly consists of an eccentric shaft, upper roller, middle roller, lower roller, conical roller, and thread plug. Through the rotation of the drill string and the applied drilling pressure, it expands and rolls the deformed parts of the casing, gradually restoring the deformed section. However, for severely deformed casings, the shaping force of the three-cone roller shaper may not be sufficient to completely restore the casing's original shape and dimensions. This may result in the shaped casing still having some deformation or insufficient inner diameter, affecting subsequent operations.

[0040] The hydraulic casing shaper consists of a conical shape, a reducing steel ball, an upper connector, and a steel ball inside a cylindrical bore. The pressure generated by the hydraulic tool is transmitted through the upper connector to the steel ball inside the cylindrical bore, causing it to move downwards. This causes the reducing steel ball to change diameter and align in a specific pattern, rolling downwards to compress the inner wall of the casing to a preset size. After pressure release, the steel ball is retracted, and the casing can continue to expand and deform after the casing string is lowered. However, because the reducing steel ball (small steel ball) and the large steel ball have single-point contact, the pressure at the contact point is very high during expansion, resulting in high rolling friction on the small steel ball, making it prone to breakage and damage, and shortening the tool's lifespan.

[0041] In view of this, such as Figures 1-5 As shown in the figure, this application provides a segmented tube expansion tool.

[0042] The split tube expansion tool includes at least one tube expansion mechanism. The tube expansion mechanism includes a connector 1, a mandrel 2, and an expansion sleeve 3.

[0043] The connector 1 is used to connect to the drive assembly or other tube expansion mechanism. The spindle 2 is used to support the expansion sleeve 3 and push the expansion sleeve 3 to expand the tube.

[0044] Specifically, the mandrel 2 includes a first part 21, a second part 22, and a third part 23 connected in sequence. The connector 1 is connected to the first part 21. The diameter of the second part 22 gradually decreases from the end connected to the first part 21 to the end connected to the third part 23 to form a conical surface 25. Furthermore, the diameter of the end of the second part 22 connected to the first part 21 is larger than the diameter of the first part 21 to form a limiting surface 24.

[0045] The diameter of the connector 1 is larger than the diameter of the first part 21. The connector 1 is provided with a blind hole and has an internal thread. The end of the first part 21 is provided with a thread that matches the internal thread of the blind hole of the connector 1. The end of the first part 21 is threaded into the blind hole of the connector 1 to achieve a detachable threaded connection.

[0046] like Figure 1 As shown, the overall diameter of the second part 22 is larger than that of the first part 21 and the third part 23. The diameter of the second part 22 is the same at the point where it connects with the third part 23, so that the connection between the second part 22 and the third part 23 forms a curved surface.

[0047] The expansion sleeve 3 is used to expand and deform the tube sleeve. Specifically, the expansion sleeve 3 is sleeved on the outside of the mandrel 2. The expansion sleeve 3 includes a straight tube and a tapered tube connected to each other. The shape of the tapered tube matches the conical surface 25. The end of the straight tube away from the tapered tube is provided with a limiting block 33 that can abut against the limiting surface 24.

[0048] The tapered tube has multiple segmented grooves arranged at intervals in the circumferential direction along its axial direction. The segmented grooves extend towards the straight tube and reach the limiting block 33 to divide the expansion sleeve 3 into multiple segmented pieces 35. The segmented grooves extending to the limiting block 33 make the segmented pieces 35 more resilient and less prone to damage when they are stretched open.

[0049] In use, the expansion mechanism is lowered into the casing 11 with the third part 23 as its front end. During the lowering process, the expansion mechanism moves from the first part 21 to the third part 23. By setting the limiting block 33, the range of motion of the expansion sleeve 3 is restricted, ensuring that the range of motion of the expansion sleeve 3 is limited to the area from the limiting surface 24 to the connector 1, thereby preventing the expansion sleeve 3 from falling off or sliding to other positions, which would render it ineffective.

[0050] The shape of the tapered tube 32 matches the conical surface 25, meaning the tapered tube 32 fits against the conical surface 25. When the conical surface 25 moves, the segmented pieces 35 adapt to fit the conical surface 25. This causes the inner diameter of the sleeve 11 to decrease in the deformed area of ​​the sleeve 11 when the expansion sleeve 3 remains stationary, preventing the expansion sleeve 3 from passing through and causing it to be stuck. If the mandrel 2 continues to advance, i.e., the conical surface 25 moves towards the second part to the third part 23, the mandrel 2 and the expansion sleeve 3 slide relative to each other. The segmented pieces 35 are then stretched open by the conical surface 25, increasing the diameter of the tapered tube and thus expanding the deformed area of ​​the sleeve 11. Furthermore, in order to prevent the segmented piece 35 from being overstretched and damaged, when the limiting block 33 abuts against the connector 1, the spindle 2 cannot continue to advance relative to the expansion sleeve 3. In this state, the segmented piece 35 is stretched to its maximum.

[0051] After the expansion is completed, when the mandrel 2 is pulled back, it moves towards the direction from the third part 23 to the second part 22, and the support of the conical surface 25 on the segmented piece 35 is eliminated. The resilience of the segmented piece 35 itself will keep it in contact with the conical surface 25, so that the diameter of the expansion sleeve 3 will also decrease and return to its initial state when the mandrel 2 is pulled back. Furthermore, when the limiting block 33 on the expansion sleeve 3 abuts against the limiting surface 24 of the mandrel 2, the expansion sleeve 3 will follow the mandrel 2 away from the deformation area of ​​the sleeve 11.

[0052] Furthermore, the taper of the second part 22 is set to 1:10. Based on comprehensive testing and research, this taper results in lower expansion pressure and less fluctuation, allowing for a larger expansion diameter. The 1:10 taper ensures close contact between the tapered structure of the expansion sleeve 3 and the conical surface 25 of the second part 22 of the mandrel 2, resulting in a more stable fit between the support surface and the conical surface, providing reliable support for the deformation of the casing 11. The 1:10 taper of the expansion sleeve 3 can adapt to varying degrees of casing 11 deformation; whether it's slight diameter reduction or more severe deformation, effective shaping and repair can be achieved by adjusting the expansion degree of the sleeve. This taper design allows the segmented expansion tool to function well in various downhole operating environments, improving the tool's versatility and adaptability.

[0053] The connector 1, while restricting the position of the expansion sleeve 3, is also used to connect a drive assembly or other expansion mechanism. The mandrel 2 is movable within the expansion sleeve 3. The end of the connector 1 away from the mandrel 2 is connected to a drive assembly, which is used to push the mandrel 2 to move and expand the plurality of the segmented pieces 35, thereby expanding the expansion sleeve 3.

[0054] like Figure 4 As shown, specifically, the drive assembly includes a multi-stage hydraulic anchor 8 and a multi-stage hydraulic booster 9; the multi-stage hydraulic booster 9 is connected to the end of the connector 1 away from the spindle 2, and the multi-stage hydraulic anchor 8 is connected to the end of the multi-stage hydraulic booster 9 away from the connector 1. An oil pipe 7 is connected to the end of the multi-stage hydraulic anchor 8 away from the multi-stage hydraulic booster 9.

[0055] The end of the connector 1 furthest from the spindle 2 also has a blind hole with internal threads. The piston output end of the multi-stage hydraulic booster 9 has a thread that matches the internal thread of the blind hole of the connector 1. The piston output end of the multi-stage hydraulic booster 9 is threaded into the blind hole at the end of the connector 1 furthest from the spindle 2. The multi-stage hydraulic booster 9 is used to push the connector 1 and the spindle 2 to open the segmented pieces 35 of the expansion sleeve 3 when the expansion sleeve 3 reaches the deformation area of ​​the sleeve 11 and cannot advance further, thereby opening the deformation area of ​​the sleeve 11 by the segmented pieces 35.

[0056] The two ends of the multi-stage hydraulic anchor 8 are connected to the multi-stage hydraulic booster 9 and the oil pipe 7, respectively. The multi-stage hydraulic anchor 8 is used to fix the multi-stage hydraulic anchor 8, the multi-stage hydraulic booster 9, and the expansion tube mechanism into the sleeve 11. This provides a force-generating basis for the multi-stage hydraulic booster 9 when it pushes the connector 1 and the spindle 2, ensuring that the multi-stage hydraulic booster 9 can push the connector 1 and the spindle 2.

[0057] The oil pipe 7 is used to connect the multi-stage hydraulic anchor 8, the multi-stage hydraulic booster 9 and the expansion tube mechanism to the outside world. The oil pipe 7 is also connected to the multi-stage hydraulic anchor 8 and the multi-stage hydraulic booster 9. The oil pipe 7 is also used to pressurize the multi-stage hydraulic anchor 8 and the multi-stage hydraulic booster 9, thereby controlling the operation of the hydraulic anchor 8 and the multi-stage hydraulic booster 9.

[0058] Furthermore, since the sleeve 11 is often irregular during deformation, in order to provide more points of force for the segmented pieces 35 when expanding the sleeve 11 and enhance the expansion strength, in this embodiment, each segmented piece 35 has multiple arc-shaped protrusions 36 on its inner and outer surfaces along the axial direction of the expansion sleeve 3, and the arc-shaped protrusions 36 on the inner surface correspond one-to-one with the arc-shaped protrusions 36 on the outer surface. The arc-shaped protrusions 36 on the inner surface can directly contact the conical surface 25, and when the conical surface 25 moves, it directly applies force to the arc-shaped protrusions 36 on the inner surface. The arc-shaped protrusions 36 on the outer surface correspond one-to-one with the arc-shaped protrusions 36 on the inner surface, that is, when the arc-shaped protrusions 36 on the inner surface are pushed by the conical surface 25, the pushing force is directly transmitted along the conical surface 25 towards the arc-shaped protrusions 36 on the inner surface and then to the arc-shaped protrusions 36 on the outer surface. In this process, the thrust of the conical surface 25 is transmitted to the arc-shaped protrusion 36 on the outer surface without changing direction; that is, the force is transmitted without misalignment. This avoids excessive misalignment force during use, which could cause deformation of the segmented piece 35. The arc-shaped protrusion 36 also reduces direct friction between the expansion sleeve 3 and the inner wall of the sleeve 11, reducing wear and extending the service life of the expansion sleeve 3.

[0059] Meanwhile, for the sleeve 11, the design of the arc-shaped protrusion 36 allows the expansion sleeve to better contact the deformed part of the sleeve 11 during the expansion process, enhancing the expansion strength and enabling the sleeve 11 to undergo more uniform plastic deformation when subjected to external force, thereby improving the shaping effect. The multiple arc-shaped protrusions 36 have good circumferential continuity, which helps ensure the roundness of the shaped sleeve 11, avoiding uneven local deformation and further improving the quality of the shaped sleeve 11.

[0060] Furthermore, the mandrel 2, the expansion sleeve 3, and the arc-shaped protrusion 36 are preferably made of bearing steel and have undergone surface hardening treatment. The expansion sleeve 3, with its high-strength material and integrated design, combined with the structure of the arc-shaped protrusion 36, makes it less prone to breakage or detachment during the tube expansion process, thus improving the overall reliability of the tool. Other high-strength materials can also be selected; this embodiment does not impose specific limitations.

[0061] Furthermore, the arc-shaped protrusions 36 are evenly distributed, and the spacing between the arc-shaped protrusions 36 is 40mm-80mm, depending on the number of arc-shaped protrusions 36.

[0062] Furthermore, in order to allow the expansion mechanism to smoothly enter the deformation area of ​​the sleeve 11 and prevent the third part 23 of the mandrel 2 from directly abutting the deformation area of ​​the sleeve 11, which would prevent the second part 22 and the expansion sleeve 3 on its outer side from entering the deformation area of ​​the sleeve 11, a guide 6 is threadedly fitted at the end of the third part 23 to guide the third part 23 into the deformation area of ​​the sleeve 11.

[0063] Specifically, the side of the guide body 6 furthest from the mandrel 2 is spherical. Due to its special shape design, the spherical guide body 6 can more easily enter the deformed sleeve 11. When the expansion mechanism moves into the deformed area of ​​the sleeve 11, the guide body 6 first reaches the inner wall of the deformed area. At this point, the spherical side of the guide body 6 contacts the inner wall of the deformed area of ​​the sleeve 11, and the smooth spherical surface of the guide body 6 slides forward along the inner wall of the sleeve without abutting against it, thus preventing the expansion mechanism from getting stuck. The contact area between the spherical surface and the inner wall of the sleeve 11 is relatively large, and the contact method is gentler, reducing the difficulty of entry caused by the deformation of the sleeve 11. Simultaneously, the spherical guide body 6 can adapt to different degrees of deformation within the sleeve 11; even if the sleeve 11 has significant bending or twisting, the spherical guide body can adapt and continue to penetrate deeper through changes in its shape.

[0064] Furthermore, to prevent the expansion sleeve 3 from slipping onto the outside of the third part 23 when the expansion mechanism is lowered into the casing 11, thus reducing the diameter of the tapered tube formed by the segmented pieces 35 in the expansion sleeve 3, an excessively small-diameter tapered tube would penetrate too deeply into the deformation area of ​​the casing 11, potentially turning a planned two-stage expansion into a single operation, increasing the burden on the expansion sleeve 3 for a single expansion. It is even possible that the tapered tube section would directly pass through the deformation area of ​​the casing 11, preventing the segmented pieces 35 from performing the expansion operation. A reset assembly is provided on the outside of the third part 23 to ensure that the expansion sleeve 3 does not slip onto the third part 23 when the expansion mechanism is lowered into the well.

[0065] Specifically, the reset assembly includes a spring seat 4 and a spring 5. One end of the spring seat 4 and the spring 5 are fixedly connected. The spring seat 4 is located close to the conical surface 25, and the inner diameter of the spring seat 4 is smaller than the outer diameter of the conical surface 25. The other end of the spring 5 abuts against the guide body 6.

[0066] The inner diameter of the spring seat 4 matches the outer diameter of the third part 23. The spring seat 4 is slidably sleeved on the outside of the third part 23, but the inner diameter of the spring seat 4 is smaller than the outer diameter of the conical surface 25, so that the spring seat 4 can only be on the third part 23. The spring seat 4 is used to abut against the expansion sleeve 3 to prevent the expansion sleeve 3 from slipping off and staying on the third part 23. The spring 5 is used to provide a force to prevent the expansion sleeve 3 from sliding to the third part 23. Simultaneously, due to the characteristics of the spring 5, the expansion sleeve 3 in its normal state will not slip onto the third part 23. When the mandrel 2 is retracted, the limiting block 33 of the expansion sleeve 3 abuts against the limiting surface 24. At this time, part of the segmented pieces 35 of the expansion sleeve 3 will slide onto the third part 23, compressing the spring 5. When part of the segmented pieces 35 slides onto the third part 23, the diameter of the tapered tube formed by the segmented pieces 35 will become smaller than the initial normal diameter, thus preventing it from jamming with the inner wall of the sleeve 11, ensuring the smooth retraction of the expansion sleeve 3 and avoiding jamming. When the retraction of the mandrel 2 stops, the compressed spring 5 pushes the expansion sleeve 3 back to its initial position, that is, pushes it back to the outside of the second part 22 of the mandrel 2.

[0067] like Figure 5 As shown, further, in an optional embodiment, when the sleeve 11 is severely deformed, the effect of one-time expansion may not be ideal, or one-time expansion is difficult, multiple expansion mechanisms can be provided, such as two expansion mechanisms.

[0068] Specifically, the segmented tube expander includes two sets of tube expander mechanisms, namely a first tube expander mechanism 12 and a second tube expander mechanism 13.

[0069] The first tube expansion mechanism 12 and the second tube expansion mechanism 13 are connected by the connector 1 in the second tube expansion mechanism 13, and the connector 1 in the first tube expansion mechanism 12 is connected to the drive assembly.

[0070] Furthermore, the diameter of the mandrel 2 of the first tube expansion mechanism 12 is larger than the diameter of the mandrel 2 of the second tube expansion mechanism 13. The second tube expansion mechanism 13, with its smaller diameter, is positioned at the front end in the forward direction, while the first tube expansion mechanism 12, with its larger diameter, is positioned at the rear. This allows for two tube expansion operations, ensuring that the inner diameter of the sleeve 11 reaches the required size and eliminating the need to replace other tube expansion tools midway.

[0071] Specifically, when using the segmented tube expander, the oil pipe 7, the multi-stage hydraulic anchor 8, the multi-stage hydraulic booster 9, and the tube expander mechanism are connected in sequence. Then, the connected segmented tube expander is lowered into the sleeve 11, with the tube expander mechanism in front. When it reaches the deformation area of ​​the sleeve 11, the guide body 6 first reaches the inner wall of the deformation area where the inner diameter of the sleeve 11 decreases. At this time, the spherical side of the guide body 6 contacts the inner wall of the deformation area of ​​the sleeve 11, and the smooth spherical side of the guide body 6 slides forward on the inner wall of the sleeve, thus carrying the mandrel 2 and the expansion sleeve 3 into the deformation area of ​​the sleeve 11. The lowering of the segmented tube expander is stopped when the expansion sleeve 3 abuts against the deformation area where the inner diameter of the sleeve 11 decreases. At this time, the segmented pieces 35 that make up the tapered tube in the expansion sleeve 3 abut against the inner wall of the deformation area of ​​the sleeve 11.

[0072] After the segmented plate 35 abuts against the inner wall of the deformable area of ​​the sleeve 11, the multi-stage hydraulic anchor 8 is pressurized through the oil pipe 7, fixing the multi-stage hydraulic anchor 8 inside the sleeve 11. The multi-stage hydraulic booster 9 and the expansion mechanism on the lower side of the multi-stage hydraulic anchor 8 are also fixed. Pressurization continues, causing the multi-stage hydraulic booster 9 to push the connector 1 and the mandrel 2 forward. During the advancement of the mandrel 2, the second part 22 of the mandrel 2 pushes the segmented plate 35 to unfold through the conical surface 25. The segmented plate 35 pushes the inner wall of the deformable area of ​​the sleeve 11 to expand outward (specifically, the arc-shaped protrusion 36 on the segmented plate 35 directly pushes the inner wall of the sleeve 11), causing the inner diameter of the deformable area of ​​the sleeve 11 to expand and recover. The segmented plate 35 achieves its maximum unfolding effect when it is pushed to the limit block 33 on the expansion sleeve 3. At this time, the inner diameter of the deformed area of ​​the sleeve 11 is fully expanded, and this state is maintained for 3 minutes to complete one sleeve expansion operation.

[0073] Then, the tube is released and retracted. After maintaining the expanded state for 3 minutes, the pressure of the multi-stage hydraulic booster 9 and the multi-stage hydraulic anchor 8 is slowly reduced. This causes the multi-stage hydraulic anchor 8 to release and the multi-stage hydraulic booster 9 to retract. The retraction of the multi-stage hydraulic booster 9 causes the connector 1 and the mandrel 2 to retract, and the second part 22 in the mandrel 2 also retracts, causing the support of the segmented piece 35 to change. The segmented piece 35 then gradually necks along with the conical surface 25 of the second part 22. When the multi-stage hydraulic booster 9 retracts to its initial position, the oil pipe 7 is lifted, causing the mandrel 2 to also be lifted. As the mandrel 2 is lifted, the limiting surface 24 of the mandrel 2 abuts against the limiting block 33 of the expansion sleeve 3, thereby causing the mandrel 2 to move the expansion sleeve 3 upward. During this process, part of the segmented piece 35 will slide to the third part 23, compressing the spring seat 4 and the spring 5. The diameter of the spinal canal formed by the segmented pieces 35 will further decrease, making it easier to lift the expansion sleeve 3. Then, after the expansion mechanism has completely left the deformed area of ​​the sleeve 11, the lifting stops. The expansion sleeve 3 no longer accelerates upwards, and the spring seat 4 and spring 5 rebound, causing the expansion sleeve 3 to return to its initial position. One expansion cycle is completed. The above steps are then repeated until the deformed area of ​​the sleeve 11 is completely repaired by the expansion, completing the expansion operation.

[0074] The segmented expansion tool provided in this application is a special tool for repairing deformed casing wells. It has high expansion strength, long service life, and is suitable for repairing deformed casing with high formation stress, high strength, and thick walls. The series of multi-stage segmented expansion tools can be used in series, avoiding the need to pull out the casing and replace the expansion tool, improving the shaping efficiency, and has broad application prospects.

[0075] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0076] It should also be noted that, in this document, the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, 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 such actual relationship or order between these entities or operations, nor should they be construed as indicating or implying relative importance. Moreover, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements, but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. In the absence of further restrictions, an element defined by the phrase "includes a..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes the element.

[0077] The technical solutions provided in this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand this application, and the content of this specification should not be construed as a limitation of this application. Furthermore, for those skilled in the art, there will be different forms of changes in the specific implementation methods and application scope based on this application. It is neither necessary nor possible to exhaustively list all implementation methods here, and obvious changes or modifications derived therefrom are still within the protection scope of this application.

Claims

1. A segmented tube expander tool, characterized in that, include: At least one tube expansion mechanism; the tube expansion mechanism includes a connector, a mandrel, and an expansion sleeve; The mandrel includes a first part, a second part, and a third part connected in sequence. The connector is connected to the first part. The diameter of the second part gradually decreases from the end connected to the first part to the end connected to the third part to form a conical surface. Furthermore, the diameter of the end of the second part that connects to the first part is larger than the diameter of the first part, so as to form a limiting surface; The expansion sleeve is fitted on the outside of the mandrel. The expansion sleeve includes a straight tube and a tapered tube connected to each other. The shape of the tapered tube matches the conical surface. The end of the straight tube away from the tapered tube is provided with a limiting block that can abut against the limiting surface. The tapered tube has multiple segmented grooves arranged at intervals in the circumferential direction along the axial direction. The segmented grooves extend towards the straight tube to the limiting block to divide the expansion sleeve into multiple segmented pieces. The mandrel is movable within the expansion sleeve. The end of the connector away from the mandrel is connected to a drive assembly, which is used to push the mandrel to move and expand the multiple segments, thereby expanding the expansion sleeve.

2. The split tube expander tool according to claim 1, characterized in that, The drive assembly includes a multi-stage hydraulic anchor and a multi-stage hydraulic booster. The multi-stage hydraulic booster is connected to the end of the connector away from the spindle, and the multi-stage hydraulic anchor is connected to the end of the multi-stage hydraulic booster away from the connector. An oil pipe is connected to the end of the multi-stage hydraulic anchor that is away from the multi-stage hydraulic booster.

3. The split tube expander tool according to claim 1, characterized in that, Each of the segmented pieces has multiple arc-shaped protrusions on its inner and outer surfaces along the axial direction of the expansion sleeve, and the arc-shaped protrusions on the inner surface correspond one-to-one with the arc-shaped protrusions on the outer surface.

4. The split tube expander tool according to claim 3, characterized in that, The spacing between the arc-shaped protrusions is 40mm-80mm.

5. The split tube expander tool according to claim 1, characterized in that, The third part is threaded with a guide body at its end, and a reset component is provided on the outside of the third part. The reset component is used to ensure that the expansion sleeve will not slip onto the third part when the expansion tube mechanism is lowered into the well.

6. The split tube expander tool according to claim 5, characterized in that, The reset assembly includes a spring seat and a spring; The spring seat and one end of the spring are fixedly connected. The spring seat is located close to the conical surface, and the inner diameter of the spring seat is smaller than the outer diameter of the conical surface. The other end of the spring abuts against the guide body.

7. The split tube expander tool according to claim 5, characterized in that, The side of the guide body away from the mandrel is spherical.

8. The split tube expander tool according to claim 1, characterized in that, The segmented tube expander includes two sets of tube expander mechanisms, namely a first tube expander mechanism and a second tube expander mechanism. The first tube expansion mechanism and the second tube expansion mechanism are connected by the connector in the second tube expansion mechanism, and the connector in the first tube expansion mechanism is connected to the drive assembly.

9. The split tube expander tool according to claim 8, characterized in that, The diameter of the mandrel of the first tube expansion mechanism is larger than the diameter of the mandrel of the second tube expansion mechanism.

10. The split tube expander tool according to claim 1, characterized in that, The taper of the second part is set to 1:10.

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