A pipe string buffering device for well repair operations

Abstract

The utility model relates to the technical field of well repair operation, concretely relates to a pipe column buffer device for well repair operation, include: slide, its surface forms the rolling surface for pipe column rolling, for pipe column rolling through on it, the device still include: blocking mechanism, its movable installation is in the slide, the blocking mechanism has the intercept position that protrudes from the rolling surface to block pipe column rolling, and the avoidance position that gives out the rolling surface after pipe column impact, the blocking mechanism moves from intercept position to avoidance position when being impacted by pipe column, to buffer the impact force of pipe column, the utility model discloses through setting movable installation on the blocking mechanism of slide, intercepts the buffer to the pipe column of rolling and realizes single orderly, and simultaneously makes the blocking mechanism automatic reset through reset mechanism, can continuously operate without manual intervention, can effectively absorb the impact energy in the process of pipe column rolling, reduces the impact noise, reduces the damage of pipe column end thread and pipe body surface.

Description

Technical Field

[0001] This utility model relates to the field of well workover operation technology, and in particular to a tubing buffer device for well workover operations. Background Technology

[0002] During well workover operations, after the tubing string is transported by the tubing conveyor, it needs to be transferred from the conveyor to the pipe rack for temporary storage. Due to the height difference between the conveyor and the pipe rack, a transition device is usually installed between the two to allow the tubing string to roll from the conveyor end to the pipe rack end, completing the transfer and storage.

[0003] Existing transition devices mainly include two types: fixed transition bridges and roller-type transition devices. Fixed transition bridges are slope structures of fixed length, with one end attached to the conveyor and the other end to the pipe rack. The pipe column rolls down the slope to the pipe rack under its own weight. Roller-type transition devices, on the other hand, have several parallel rollers arranged between the conveyor and the pipe rack, and the pipe column rolls on the rollers to achieve transfer. In actual use, the pipe column has a certain speed and impact energy when rolling out of the conveyor. During the rolling process, it collides with the transition device and existing pipe columns on the pipe rack, generating significant impact and noise. The threads at the pipe ends and the surface of the pipe body are easily damaged. Furthermore, when multiple pipe columns roll down simultaneously, they collide and squeeze each other, easily leading to safety accidents. Utility Model Content

[0004] In view of this, the purpose of this utility model is to propose a tubing buffer device for well workover operations, so as to achieve the orderly passage of a single tubing while reducing impact and noise, while ensuring smooth transfer of the tubing.

[0005] To achieve the above objectives, this utility model provides a tubing buffer device for well workover operations, comprising:

[0006] The slide has a surface that forms a rolling surface for the tubing to roll over;

[0007] The device further includes:

[0008] A blocking mechanism is movably mounted on the slide rail. The blocking mechanism has an intercepting position protruding from the rolling surface to block the rolling of the tube column, and a yielding position that allows the rolling surface to be cleared after being impacted by the tube column. When the blocking mechanism is impacted by the tube column, it moves from the intercepting position to the yielding position to buffer the impact force of the tube column.

[0009] A reset mechanism, connected to the blocking mechanism, is used to drive the blocking mechanism back from the avoidance position to the interception position after the column has passed.

[0010] The slide is a ramp-type slide that extends in a long strip. The blocking mechanism is a movable blocking member that is movably installed on the slide. The reset mechanism is an elastic reset member. When the movable blocking member is impacted by a tube rolling along the slide direction, it moves along a predetermined trajectory to absorb the impact energy and is reset to the interception position by the elastic reset member after the tube passes.

[0011] A limiting structure is provided between the movable blocking member and the slide rail. The limiting structure is used to limit the movement trajectory and range of the movable blocking member, so that the movable blocking member can only move between the interception position and the avoidance position.

[0012] The movable blocking component is a limiting block hinged to the slide rail. The limiting block is mounted on the slide rail via a hinge shaft. The elastic reset component is a tension spring. One end of the tension spring is connected to the limiting block, and the other end is connected to the slide rail. The tension spring applies tension to the limiting block, keeping it in the intercept position and allowing it to rotate only in one direction around the hinge axis to avoid the obstruction position. After the pipe column passes, the limiting block is pulled back to the intercept position. The slide rail includes a guide frame and a shock absorber hinged together by a limiting pin. The angle between the guide frame and the shock absorber is adjustable to accommodate pipe racks of different heights.

[0013] The slide rail includes a roller body with a rolling surface formed on its upper end for the tube column to roll. The movable blocking component is a stop bar slidably disposed within the slide rail. The stop bar is fixedly connected to a slider, which is slidably installed in a groove on the side wall of the slide rail. The limiting structure is the end wall of the groove, used to restrict the slider to slide only within the groove. The elastic reset component is a compression spring, with one end abutting against the slider and the other end abutting against the slide rail. The groove has an inclined angle. As the stop bar slides along the groove with the slider, the length of the stop bar extending beyond the surface of the slide rail gradually changes. When the tube column pushes the stop bar to a point where the exposed length of the stop bar is less than the radius of the tube column, the tube column disengages from the stop bar. The blocking mechanism has at least two stages along the rolling direction of the tube column, and the tube column decelerates step by step as it passes through each stage of the blocking mechanism.

[0014] The guide frame is provided with a first shock-absorbing pad, and the shock-absorbing seat is provided with a second shock-absorbing pad. Both the first and second shock-absorbing pads are made of polyurethane or rubber and are used to buffer and reduce noise from the rolling tube column.

[0015] The upper surface of the slide is provided with a third shock-absorbing pad, which is installed in the area of ​​the upper surface of the slide other than the slide groove. When the stop bar slides in the slide groove, the third shock-absorbing pad buffers and reduces noise for the rolling tube column. The third shock-absorbing pad is made of polyurethane or rubber.

[0016] The two-stage blocking mechanism is a first-stage blocking mechanism and a second-stage blocking mechanism in sequence along the rolling direction of the tube column. The first-stage blocking mechanism and the second-stage blocking mechanism have the same structure. The stop bar of the first-stage blocking mechanism is reset by the corresponding compression spring after the tube column passes through. The stop bar of the second-stage blocking mechanism is also reset by the corresponding compression spring after the tube column passes through. The tube column rolls out of the slide after being buffered by the first-stage blocking mechanism and the second-stage blocking mechanism in sequence.

[0017] The shock absorber seat has a semi-circular groove at the end away from the guide frame. The semi-circular groove is used to hold the limiting pipe string of the pipe rack, so as to realize the quick connection between the well workover operation pipe string buffer device and the pipe rack. The guide frame has a connecting hole at the end away from the shock absorber seat. The connecting hole is used to hinge with the conveyor through a pin.

[0018] The slide is a square box structure, the slide groove is set on the two side walls of the square box structure, the compression spring is set inside the square box structure, and a spring support is fixedly set at the bottom of the square box structure. The lower end of the compression spring abuts against the spring support and the upper end abuts against the slider. The inside of the square box structure is a hollow structure to accommodate the slider, the compression spring and the spring support.

[0019] The beneficial effects of this utility model are as follows: By setting a blocking mechanism that is movably installed on the slide, this utility model intercepts and buffers the rolling pipe column and enables the orderly passage of a single pipe column. At the same time, the blocking mechanism is automatically reset by the reset mechanism, so that continuous operation can be carried out without manual intervention. It can effectively absorb the impact energy during the rolling of the pipe column, reduce impact noise, reduce damage to the threads at the pipe column end and the surface of the pipe body, prevent collision and squeezing caused by multiple pipe columns rolling down at the same time, and improve the safety of operation. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present utility model;

[0022] Figure 2 This is a schematic diagram of the guide frame, tension spring, and limiting block structure of Embodiment 1 of this utility model;

[0023] Figure 3 This is a structural schematic diagram of Embodiment 2 of the present invention.

[0024] The following are marked in the diagram: 1. Conveyor; 2. Guide frame; 3. Pipe rack; 4. Shock absorber; 5. Limiting column; 6. Limiting pin; 7. Tension spring; 8. Limiting block; 9. Conveyor V-groove; 10. Roller body; 11. Slider; 12. Stop bar; 13. Third shock absorber pad; 14. Spring support; 15. Compression spring; 16. Column; 17. Slide. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to specific embodiments.

[0026] It should be noted that, unless otherwise defined, the technical or scientific terms used in this utility model should have the ordinary meaning understood by one of ordinary skill in the art to which this utility model pertains. The terms "first," "second," and similar terms used in this utility model do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0027] Example 1

[0028] Reference Figure 1 and Figure 2 This utility model provides a tubing buffer device for well workover operations, mainly including a slide, a blocking mechanism, and a reset mechanism. The slide is used for the tubing string 16 to roll through it, the blocking mechanism is movably installed on the slide and used to block and buffer the rolling tubing string 16, and the reset mechanism is connected to the blocking mechanism and used to reset the blocking mechanism after the tubing string 16 has passed through.

[0029] like Figure 1As shown, the slide is elongated, with its surface forming a rolling surface for the tube column 16 to roll. The slide specifically includes a guide frame 2 and a shock absorber 4, which are hinged together by a limiting pin 6. This allows the angle between the guide frame 2 and the shock absorber 4 to be adjusted according to actual working conditions, thus adapting to different heights of the pipe rack 3. The end of the guide frame 2 away from the shock absorber 4 has a connecting hole, which is used to hinge with the conveyor 1 via a pin, connecting one end of the entire buffer device to the conveyor 1. The end of the shock absorber 4 away from the guide frame 2 has a semi-circular groove, which is used to hold the limiting tube column 5 of the pipe rack 3, enabling a quick connection between the other end of the buffer device and the pipe rack 3. Through this connection method of hinged connection at one end and holding at the other, the entire buffer device can be quickly installed, and the adjustable angle between the guide frame 2 and the shock absorber 4 allows the device to flexibly adapt to different height differences between the conveyor 1 and the pipe rack 3.

[0030] Both the guide frame 2 and the shock absorber seat 4 are equipped with shock-absorbing pads on their upper surfaces. Specifically, the guide frame 2 is provided with a first shock-absorbing pad, and the shock absorber seat 4 is provided with a second shock-absorbing pad. Both the first and second shock-absorbing pads are made of polyurethane or rubber and are used to buffer and reduce noise from the rolling tube column 16. When the tube column 16 rolls out of the conveyor V-groove 9 of the conveyor 1 and rolls along the upper surfaces of the guide frame 2 and the shock absorber seat 4, the shock-absorbing pads can effectively absorb the impact energy between the tube column 16 and the slide, reduce impact noise, and protect the surface of the tube column 16 from damage.

[0031] Reference Figure 1 and Figure 2 The blocking mechanism is mounted on the guide frame 2, specifically a limiting block 8 hinged to the guide frame 2. The limiting block 8 is roughly trigger-shaped (similar to the L-shaped or arc-shaped structure of a pistol trigger), with its central part rotatably connected to the guide frame 2 via a hinge axis, allowing the limiting block 8 to swing within a certain angle range around the hinge axis. The upper end of the limiting block 8 forms a blocking portion, which protrudes from the upper surface (i.e., the rolling surface) of the guide frame 2 to block the tube column 16; the lower end of the limiting block 8 is a connecting end for connection to the tension spring 7. The bottom of the guide frame 2 has an ear plate with a connecting hole for connection to one end of the tension spring 7. The side of the limiting block 8 has a step; when the limiting block 8 rotates to the avoidance position, this step abuts against the guide frame 2 to limit the continued rotation of the limiting block 8, thereby limiting the range of movement of the limiting block 8 from the interception position to the avoidance position.

[0032] The limiting block 8 has an intercepting position protruding from the rolling surface and a clearance position that allows the rolling surface to be cleared after being impacted by the tube column 16. In the intercepting position, the blocking part of the limiting block 8 protrudes from the upper surface of the guide frame 2 and can block the tube column 16 rolling along the slide. When the tube column 16 impacts the blocking part of the limiting block 8, the limiting block 8 swings backward about the hinge axis (rotates away from the rolling surface) to the clearance position, and the blocking part retracts below the rolling surface or moves to the side of the rolling surface, allowing the rolling surface to be cleared for the tube column 16 to pass.

[0033] The reset mechanism is a tension spring 7. Each end of the tension spring 7 has a hook; one hook connects to the ear plate at the bottom of the guide frame 2, and the other hook connects to the lower end of the limit block 8. The tension spring 7 applies a backward pulling force to the limit block 8, keeping the blocking part of the limit block 8 in the intercept position when no external force is applied. Simultaneously, a limiting structure is provided between the limit block 8 and the guide frame 2. This limiting structure restricts the movement trajectory and range of the limit block 8, ensuring that the limit block 8 can only move between the intercept position and the avoidance position. Specifically, the tension spring 7 can only withstand tensile loads and cannot be compressed. This physical characteristic constitutes the natural limiting function of the stop block 8. When no external force is applied, the tension spring 7 is always in a tensioned state and applies a pulling force to the stop block 8, keeping its blocking part in the intercept position and preventing it from rotating further away from the avoidance position. When the tubing 16 impacts the stop block 8, the tension spring 7 is stretched, and the stop block 8 rotates from the intercept position to the avoidance position to free up the rolling surface. After the tubing 16 passes, the tension spring 7 springs back to its original position, pulling the stop block 8 back to the intercept position. Throughout the entire operation, the stop block 8 can only move between the intercept position and the avoidance position, and the unidirectional limiting is achieved by the unidirectional bearing characteristic of the tension spring 7.

[0034] When the pipe column buffer device of Embodiment 1 of this utility model is working, the guide frame 2 is first hinged to the conveyor 1 through the pin shaft, the shock absorber 4 is held on the limiting pipe column 5 of the pipe rack 3 through the semi-circular slot, and the included angle between the guide frame 2 and the shock absorber 4 is adjusted according to the height of the pipe rack 3 so that the slide forms an appropriate tilt angle.

[0035] After the tube column 16 rolls out of the V-groove 9 of the conveyor 1, it rolls laterally toward the guide frame 2 perpendicular to the length of the slide, rolling along the rolling surface of the upper surface of the guide frame 2 toward the shock absorber 4. The tube column 16 first encounters a limiting block 8 protruding from the rolling surface. The blocking part of the limiting block 8 blocks the tube column 16, absorbing some of its impact energy. Under the impact of the tube column 16, the limiting block 8 overcomes the tension of the tension spring 7 and rotates unidirectionally around the hinge axis from the intercepting position to the yielding position. The blocking part swings backward and retracts, allowing the rolling surface for the tube column 16 to pass. During this process, the step on the side of the limiting block 8 abuts against the guide frame 2 to limit the rotation range of the limiting block 8, preventing excessive rotation and ensuring the stability and reliability of the movement. After passing the limiting block 8, the tube column 16 continues to roll along the rolling surface of the upper surface of the shock absorber 4, finally falling into the tube rack 3. After the tube column 16 passes through, the tension spring 7 pulls the limit block 8 back to the intercept position, waiting for the next tube column 16 to arrive.

[0036] During the above process, the first damping pad on the guide frame 2 and the second damping pad on the damping seat 4 buffer and reduce noise for the rolling tube column 16, further reducing the impact and noise between the tube column 16 and the slide.

[0037] Example 2

[0038] Reference Figure 3 This utility model provides another tubing buffer device for well workover operations in Embodiment 2. Unlike Embodiment 1, the slide in this embodiment is a square box structure, specifically including a roller body 10. The roller body 10 extends in a long strip shape, with its upper end forming a rolling surface for the tubing string 16 to roll. The interior of the roller body 10 is a hollow structure to accommodate related components. A third shock-absorbing pad 13 is provided on the upper surface of the roller body 10 (i.e., the rolling surface). The third shock-absorbing pad 13 is installed on the upper surface of the roller body 10, excluding the sliding groove 17, and is made of polyurethane or rubber, used to buffer and reduce noise from the rolling tubing string 16.

[0039] The roller body 10 has grooves 17 on both sides. The grooves 17 are inclined along the rolling direction of the tube column 16, that is, the grooves 17 have an inclination angle. The end walls of the grooves 17 form a limiting structure to limit the sliding range of the slider 11.

[0040] Reference Figure 3 The blocking mechanism is a stop bar 12 that is slidably disposed within the slide rail. A slider 11 is fixedly connected to the stop bar 12, and the slider 11 is slidably mounted within the slide grooves 17 on both sides of the roller body 10. One end of the stop bar 12 is located above the roller body 10 (i.e., above the rolling surface), and the other end passes through the slide groove 17 and is fixedly connected to the slider 11. When the slider 11 slides within the slide groove 17, the stop bar 12 moves synchronously with the slider 11, and the length of the stop bar 12 extending beyond the upper surface of the roller body 10 also changes accordingly.

[0041] The reset mechanism is a compression spring 15. The compression spring 15 is located inside the roller body 10, with one end abutting against the slider 11 and the other end abutting against the roller body 10. Specifically, a spring support 14 is fixedly mounted at the bottom of the roller body 10, with the lower end of the compression spring 15 abutting against the spring support 14 and the upper end abutting against the slider 11. The hollow structure inside the roller body 10 accommodates the slider 11, the compression spring 15, and the spring support 14.

[0042] In this embodiment, the blocking mechanism has at least two stages along the rolling direction of the tube column 16. Specifically, a first-stage blocking mechanism and a second-stage blocking mechanism are sequentially arranged along the rolling direction of the tube column 16, and the first-stage blocking mechanism and the second-stage blocking mechanism have the same structure. Each stage of the blocking mechanism includes its corresponding stop bar 12, slider 11, slide groove 17 and compression spring 15.

[0043] In the second embodiment of this utility model, when the tubular buffer device is in operation, the tubular column 16 rolls out of the conveyor and rolls laterally towards the upper surface of the roller body 10 in a manner perpendicular to the length direction of the slide. The tubular column 16 first encounters the stop bar 12 of the first-stage blocking mechanism. At this time, the stop bar 12 protrudes from the upper surface (i.e., the rolling surface) of the roller body 10 and is in the interception position, thus blocking the rolling tubular column 16.

[0044] The tubular column 16 impacts the stop bar 12 under its own weight and inertia, pushing the stop bar 12 downwards. The stop bar 12 drives the slider 11 to slide downwards along the inclined groove 17, while the compression spring 15 is compressed, absorbing the impact energy of the tubular column 16. As the slider 11 slides along the groove 17, the length of the stop bar 12 extending beyond the upper surface of the roller body 10 (i.e., the exposed length) gradually shortens. When the exposed length of the stop bar 12 decreases to less than the radius of the tubular column 16, the center of gravity of the tubular column 16 has passed the top of the stop bar 12, and the tubular column 16 automatically disengages from this stage of the stop bar 12 under the action of gravity. Subsequently, the compression spring 15 of this stage of the blocking mechanism resets, pushing the slider 11 and the stop bar 12 back to their initial positions.

[0045] After disengaging from the first-stage blocking mechanism, the tube column 16 continues rolling to the second-stage blocking mechanism. The second-stage blocking mechanism cushions the tube column 16 in the same way, causing it to push the stop bar 12 of the second-stage blocking mechanism again, compressing the corresponding compression spring 15. Once the exposed length of the stop bar 12 is less than the radius of the tube column 16, the tube column 16 disengages from the second-stage blocking mechanism. Thus, the tube column 16, after being cushioned step-by-step by the first and second-stage blocking mechanisms, rolls off the upper surface of the roller body 10. During this process, the third damping pad 13 on the upper surface of the roller body 10 cushions and reduces noise from the rolling tube column 16.

[0046] It should be noted that since the tube column 16 rolls laterally towards the slide (i.e., the axis of the tube column 16 is perpendicular to the length direction of the slide), the circular cross-section of the tube column 16 faces the stop bar 12. When the exposed length of the stop bar 12 is less than the radius of the tube column 16, the top of the stop bar 12 is lower than the center height of the tube column 16, and the center of gravity of the tube column 16 has passed the top of the stop bar 12. Therefore, the tube column 16 can naturally disengage from this stage of the blocking mechanism and continue to roll forward.

[0047] Both embodiments described above relate to a tubing buffer device for well workover operations. Their common technical concept includes a long, elongated slide (in Embodiment 1, this is a slide composed of a guide frame 2 and a shock absorber 4; in Embodiment 2, it is a roller body 10), with the slide surface forming a rolling surface for the tubing string 16 to roll. Both also include a blocking mechanism movably mounted on the slide (in Embodiment 1, a limiting block 8; in Embodiment 2, a stop bar 12), which has an interception position protruding from the rolling surface and a clearance position that yields to the rolling surface after impact by the tubing string 16. Both also include a reset mechanism connected to the blocking mechanism (in Embodiment 1, a tension spring 7; in Embodiment 2, a compression spring 15), used to reset the blocking mechanism from the clearance position to the interception position after the tubing string 16 has passed. The difference between the two embodiments lies in the specific implementation of the blocking mechanism: Embodiment 1 uses a hinged rotation method, while Embodiment 2 uses a sliding method. However, both achieve the functions of buffering the tubing string 16 and allowing for the orderly passage of individual tubing.

[0048] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this utility model is limited to these examples; within the framework of this utility model, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of this utility model as described above, which are not provided in the details for the sake of brevity. Any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A tubing buffer device for well workover operations, comprising: The slide has a surface that forms a rolling surface for the tube string (16) to roll over; The device is characterized in that it further includes: A blocking mechanism is movably mounted on the slide. The blocking mechanism has an intercepting position protruding from the rolling surface to block the rolling of the tube column (16), and a yielding position that yields the rolling surface after being impacted by the tube column (16). When the blocking mechanism is impacted by the tube column (16), it moves from the intercepting position to the yielding position to buffer the impact force of the tube column (16). A reset mechanism, which is connected to the blocking mechanism, is used to return the blocking mechanism from the avoidance position to the intercept position when the column (16) passes through the rear drive.

2. The well workover tubing buffer device according to claim 1, characterized in that, The slide is a ramp-type slide and extends in a long strip. The blocking mechanism is a movable blocking member that is movably set on the slide. The reset mechanism is an elastic reset member. When the movable blocking member is impacted by the tube column (16) rolling along the slide direction, it moves along a predetermined trajectory to absorb the impact energy and is reset to the interception position by the elastic reset member after the tube column (16) passes.

3. The well workover tubing buffer device according to claim 2, characterized in that, A limiting structure is provided between the movable blocking member and the slide rail. The limiting structure is used to limit the movement trajectory and range of the movable blocking member, so that the movable blocking member can only move between the interception position and the avoidance position.

4. The well workover tubing buffer device according to claim 3, characterized in that, The movable blocking component is a limiting block (8) hinged on the slide. The limiting block (8) is installed on the slide via a hinge shaft. The elastic reset component is a tension spring (7). One end of the tension spring (7) is connected to the limiting block (8), and the other end is connected to the slide. The tension spring (7) applies tension to the limiting block (8), so that the limiting block (8) is held in the intercept position and can only rotate unidirectionally around the hinge axis to avoid the position. After the pipe column (16) passes, the limiting block (8) is pulled back to the intercept position. The slide includes a guide frame (2) and a shock absorber (4) hinged together by a limiting pin (6). The included angle between the guide frame (2) and the shock absorber (4) is adjustable to adapt to pipe racks (3) of different heights.

5. The well workover tubing buffer device according to claim 3, characterized in that, The slide rail includes a roller body (10), the upper end face of which forms a rolling surface for the tube column (16) to roll. The movable blocking component is a stop bar (12) slidably disposed in the slide rail. The stop bar (12) is fixedly connected to a slider (11). The slider (11) is slidably installed in a groove (17) on the side wall of the slide rail. The limiting structure is the end wall of the groove (17) to restrict the slider (11) to slide only in the groove (17). The elastic reset component is a compression spring (15). One end of the compression spring (15) is connected to the slider (11). One end abuts against the other end and the other end abuts against the slide rail; the slide rail (17) has an inclined angle, and when the stop rod (12) slides along the slide rail (17) with the slider (11), the length of the stop rod (12) extending out of the slide rail surface gradually changes. When the column (16) pushes the stop rod (12) to move to the point where the exposed length of the stop rod (12) is less than the radius of the column (16), the column (16) disengages from the stop rod (12); the blocking mechanism is provided with at least two levels along the rolling direction of the column (16), and the column (16) passes through each level of the blocking mechanism to achieve progressive deceleration.

6. The well workover tubing buffer device according to claim 4, characterized in that, The guide frame (2) is provided with a first shock-absorbing pad, and the shock-absorbing seat (4) is provided with a second shock-absorbing pad. Both the first and second shock-absorbing pads are made of polyurethane or rubber and are used to buffer and reduce noise from the rolling column (16).

7. The well workover tubing buffer device according to claim 5, characterized in that, The upper surface of the slide is provided with a third shock-absorbing pad (13). The third shock-absorbing pad (13) is installed on the upper surface of the slide in areas other than the slide groove (17). When the stop bar (12) slides in the slide groove (17), the third shock-absorbing pad (13) buffers and reduces noise on the rolling tube column (16). The third shock-absorbing pad (13) is made of polyurethane or rubber.

8. The well workover tubing buffer device according to claim 5, characterized in that, The two-stage blocking mechanisms are, in sequence, a first-stage blocking mechanism and a second-stage blocking mechanism along the rolling direction of the tube column (16). The first-stage blocking mechanism and the second-stage blocking mechanism have the same structure. The stop bar (12) of the first-stage blocking mechanism is reset by the corresponding compression spring (15) after the tube column (16) passes through. The stop bar (12) of the second-stage blocking mechanism is reset by the corresponding compression spring (15) after the tube column (16) passes through. The tube column (16) rolls out of the slide after being buffered by the first-stage blocking mechanism and the second-stage blocking mechanism in sequence.

9. The well workover tubing buffer device according to claim 4, characterized in that, The shock absorber (4) is provided with a semi-circular groove at one end away from the guide frame (2). The semi-circular groove is used to hold the limiting pipe string (5) of the pipe rack (3) to realize the quick connection between the well repair operation pipe string buffer device and the pipe rack (3). The guide frame (2) is provided with a connecting hole at one end away from the shock absorber (4). The connecting hole is used to be hinged to the conveyor (1) through a pin.

10. The well workover tubing buffer device according to claim 5, characterized in that, The slide is a square box structure. The slide groove (17) is set on the two side walls of the square box structure. The compression spring (15) is set inside the square box structure. A spring support (14) is fixedly set at the bottom of the square box structure. The lower end of the compression spring (15) abuts against the spring support (14) and the upper end abuts against the slider (11). The inside of the square box structure is a hollow structure, which is used to accommodate the slider (11), the compression spring (15) and the spring support (14).

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