A directional synchronous tractor unit that crosses the main pipeline and outer tube

Abstract

A return towing head for directional synchronous crossing of a main pipeline and an outer casing, relating to the field of pipeline crossing technology, includes an outer casing, a main pipeline, and a return towing head. Reinforcing plates are welded to the outer wall of the outer casing at equal intervals along the circumference. The return towing head includes a main body, with tie rods evenly spaced along the circumference at the ends of the main body. The tie rods can extend between two reinforcing plates, and a limiting plate is provided at the end of the tie rod. When the outer casing and the return towing head need to connect, the limiting plate is placed horizontally on the reinforcing plates on both sides, thus forming an effective connection. A central cylinder is provided inside the main body, and a top block is slidably mounted radially upward on the central cylinder. One end of the top block can abut against the inner wall of the main pipeline. A drag rod is slidably mounted axially upward on the central cylinder, and the drag rod has a conical portion. The other end of the top block can abut against the conical portion of the drag rod. When the drag rod is dragged outward, the conical portion pushes the top block out and presses it tightly against the inner wall of the main pipeline. Thus, this application achieves synchronous dragging of the outer casing and the main pipeline by the return towing head.

Description

Technical Field

[0001] This utility model belongs to the field of pipeline crossing technology, and in particular relates to a return tractor for directional synchronous crossing of main pipeline and outer casing. Background Technology

[0002] When oil and gas pipelines (i.e., the main pipelines in this application) cross rivers, highways, and railways, the conventional method to avoid excavation is to use underground directional crossing technology. In order to prevent leakage of the oil and gas pipelines during crossing, an outer casing needs to be added to the outside of the oil and gas pipeline. There is an annular space between the outer casing and the oil and gas pipeline. By monitoring the annular space later, it is possible to know whether there is leakage in the oil and gas pipeline during crossing.

[0003] Pullback is a key step in horizontal directional drilling to pull the pipe into the borehole. It refers to pulling the prefabricated pipe into the enlarged borehole by rotating the drill rod backward.

[0004] Currently, when directional drilling for oil and gas pipelines requires the installation of an outer casing, the oil and gas pipeline and the outer casing are usually pulled back in two separate steps. This two-step pullback increases the workload and also increases the wear between the outer wall of the oil and gas pipeline and the outer casing, which can scratch the anti-corrosion layer. Therefore, designing a device that allows for the simultaneous pullback of the outer casing and the oil and gas pipeline is the challenge that this application aims to overcome.

[0005] In existing technologies, some pullback heads are welded to the outer casing. The advantages of welding are: 1. High connection strength; 2. Sealing the end of the outer casing, preventing soil or mud from entering the outer casing during pullback. However, the disadvantages of welding are: before pullback, the outer casing is welded to the pullback head on site, and after pullback, the outer casing is cut off on site. This process of welding before pullback and cutting off after pullback is too labor-intensive and not conducive to improving work progress.

[0006] In existing technology, a portion of the pullback head and the outer sleeve are connected by a through shaft. Its advantages are: 1. Fast connection speed. Its disadvantages are: after pullback, two holes are left on the outer sleeve wall, requiring the perforated section to be cut off later (i.e., a section of the outer sleeve needs to be cut off). Cutting off the outer sleeve increases workload, and the cut is difficult to make smooth, affecting the quality of subsequent construction. Utility Model Content

[0007] To enable simultaneous pullback of the outer pipe and the main pipe, and to facilitate rapid connection and disassembly of the pullback head and the outer pipe, this invention provides a pullback head that can simultaneously pull back the outer pipe and the main pipe. This invention can simultaneously pull back the outer pipe and the main pipe, and also enables rapid connection and disassembly of the pullback head with both the outer pipe and the main pipe.

[0008] The technical solution provided by this utility model is: a directional synchronous traversing main pipeline and outer sleeve return tractor, including an outer sleeve, a main pipeline, and a return tractor. The outer sleeve is fitted over the main pipeline, with an annular space between the outer sleeve and the main pipeline. During any idle time before return traversal, reinforcing plates are welded to the outer wall of the outer sleeve at equal intervals along the circumference. The return tractor includes a main body, with tie rods evenly spaced along the circumference at one end of the main body near the outer sleeve. One end of the tie rod is fixedly connected to the main body, while the other end is free. The free end of the tie rod can extend between two reinforcing plates, and a limiting plate is provided at the free end of the tie rod. The limiting plate can abut against the reinforcing plates, and its length is greater than the distance between the two reinforcing plates. The limiting plate and the tie rod are connected by a pin. When the outer sleeve needs to connect with the return tractor, the limiting plate is horizontally supported. On the reinforcing plates on both sides, the movement of the return towing head drives the pull rod to move, the movement of the pull rod drives the limit plate to move, and the limit plate drags the reinforcing plate and the outer sleeve to move, thus forming an effective connection, and the effective connection process is fast; a central cylinder is provided on the inner side of the main body, and the central cylinder can be an integral structure with the main body. The central cylinder is inserted into the interior of the main pipeline. A top block is slidably provided on the radial side of the central cylinder. One end of the top block can abut against the inner wall of the main pipeline. A drag rod is slidably provided on the axial side of the central cylinder. One end of the drag rod passes through the central cylinder and the main body in sequence and extends out of the main body. The other end of the drag rod has a conical part. The other end of the top block can abut against the conical part of the drag rod. Thus, when the drag rod is dragged outward, the conical part pushes the top block out and presses it tightly against the inner wall of the main pipeline. Thus, this application realizes that the return towing head synchronously drags the outer sleeve and the main pipeline.

[0009] A further technical solution is: an anti-top ring is fitted on the outer side of the main pipeline. The thickness of the anti-top ring is not less than twice the wall thickness of the main pipeline. The position of the anti-top ring corresponds to the top block. The anti-top ring plays a supporting role on the outer wall of the main pipeline to prevent the main pipeline from being deformed by the top block.

[0010] A further technical solution is as follows: a sealing cylinder is slidably installed between the main body and the central cylinder. One end face of the sealing cylinder can abut against the end face of the outer sleeve, thereby forming a seal on the end face of the outer sleeve. A spring is installed between the other end face of the sealing cylinder and the main cylinder. Under the elastic force of the spring, the sealing cylinder has a tendency to move closer to the outer sleeve. An elastic sealing layer is installed at the contact point between the sealing cylinder and the outer sleeve. The sealing cylinder seals the end face of the outer sleeve, preventing soil from entering the outer sleeve and preventing the annular space between the main pipeline and the outer sleeve from being blocked by soil. This ensures that the leakage of the main pipeline can be monitored through the annular space in the future.

[0011] A further technical solution is: the portion of the tow rod extending beyond the main body is threadedly connected to a limiting nut, and the end face of the limiting nut abuts against the main body.

[0012] A further technical solution is: a strong magnetic core is provided on the inner side of the drag bar corresponding to the cone part, and the top block is made of stainless steel. The strong magnetic core has a strong attraction to the top block, and when the top block has an inward closing space, the top block can automatically move towards the strong magnetic core.

[0013] A further technical solution is that the outer contour of the main body is conical.

[0014] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0015] 1. This utility model pre-welds reinforcing plates to the outer wall of the outer sleeve. These reinforcing plates can be installed during any idle period before the pullback operation, and no further processing is required after the pullback. When connecting the pullback head to the outer sleeve, the pull rod of the pullback head is inserted into the gap between the reinforcing plates. The limiting plate and the pull rod are then connected together via a pin. Since the length of the limiting plate is greater than the gap between the reinforcing plates, one limiting plate can limit the movement of the adjacent reinforcing plates on both sides. As the pull rod moves the limiting plate, it also pulls the reinforcing plates and the outer sleeve, thus connecting the outer sleeve to the pullback head. When separating the pullback head from the outer sleeve, the pin between the limiting plate and the pull rod is simply pulled out. Therefore, compared with existing technologies, the connection and separation of the pullback head and the outer sleeve in this utility model are very rapid, and no processing of the outer sleeve is required after separation, significantly reducing workload. Furthermore, the original flat end of the outer sleeve is preserved, facilitating smooth subsequent construction.

[0016] 2. This utility model uses a top block to tighten the main pipeline from inside. Dragging the tow bar further increases the pre-tension force of the top block on the main pipeline, forcing the main pipeline to connect with the return tow head and move along with it. Therefore, the return tow head of this utility model can synchronously drag the outer sleeve and the main pipeline.

[0017] 3. The sealing cylinder of this utility model has the function of sealing the end of the outer sleeve, preventing soil from entering the main pipeline, ensuring that the annular space between the main pipeline and the outer sleeve is in a pass, and ensuring that the leakage of the main pipeline can be monitored through the annular space in the future. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of the present invention.

[0019] Figure 2 This is a unfolded view of the outer wall of the outer sleeve in this utility model.

[0020] Figure 3 This is an unfolded view of the outer wall of the main body in this utility model.

[0021] Figure 4 This is a view showing the limiting relationship between the tie rod on the outer wall of the main body and the reinforcing plate on the outer wall of the outer sleeve.

[0022] In the diagram: 1. Outer tube; 2. Main pipeline; 3. Annular space; 4. Limiting plate; 5. Reinforcing plate; 6. Pull rod; 7. Main body; 8. Central cylinder; 9. Limiting nut; 10. Trailing rod; 11. Spring; 12. Sealing cylinder; 13. Strong magnetic core; 14. Anti-top ring; 15. Top block. Detailed Implementation

[0023] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0024] This embodiment includes an outer tube 1, a main line 2, and a return head. The outer tube 1 is fitted over the main line 2, and an annular space 3 is left between the outer tube 1 and the main line 2.

[0025] like Figure 2 As shown, during any idle time before the pullback begins, reinforcing plates 5 are welded to the outer wall of the outer casing 1 at equal intervals along the circumference (the reinforcing plates 5 can even be included at the factory, so the time spent welding the reinforcing plates 5 is not wasted during the pipeline crossing cycle). Figure 1-4 As shown, the backhaul head includes a main body 7. At one end of the main body 7 near the outer sleeve 1, pull rods 6 are evenly spaced circumferentially. One end of the pull rod 6 is fixedly connected to the main body 7 (in this embodiment, the pull rod 6 and the main body 7 are an integral structure), and the other end of the pull rod 6 is free. The free end of the pull rod 6 can extend between two reinforcing plates 5. A limiting plate 4 is provided at the free end of the pull rod 6. The limiting plate 4 can abut against the reinforcing plates 5. The length of the limiting plate 4 is greater than the distance between the two reinforcing plates 5. The limiting plate 4 and the pull rod 6 are connected by a pin or a bolt. When the outer sleeve 1 needs to connect with the backhaul head, the procedure is as follows: Figure 4 As shown, the limiting plate 4 is horizontally supported on the reinforcing plates 5 on both sides. The movement of the pull head drives the pull rod 6 to move, and the movement of the pull rod 6 drives the limiting plate 4 to move. Since the limiting plate 4 abuts against the reinforcing plate 5 and has a limiting effect on the reinforcing plate 5, the limiting plate 4 also drags the reinforcing plate 5 and the outer sleeve 1 to move, thus forming an effective connection. Moreover, the effective connection process is fast. A central cylinder 8 is provided on the inner side of the main body 7. The central cylinder 8 can be integrated with the main body 7. The central cylinder 8 is inserted into the interior of the main pipeline 2. A top block 15 is slidably provided on the radial side of the central cylinder 8. One end of the top block 15 can abut against the inner wall of the main pipeline 2. A drag rod 10 is slidably provided on the axial side of the central cylinder 8. Figure 1In the middle, the right end of the tow bar 10 passes through the central cylinder 8 and the main body 7 in sequence and extends out of the main body 7. The left end of the tow bar 10 has a conical part, and the other end of the top block 15 can abut against the conical part of the tow bar 10. Thus, when the tow bar 10 is dragged outward, the conical part pushes the top block 15 out and presses it against the inner wall of the main pipeline 2. Thus, this application realizes that the return tow head synchronously drags the outer sleeve 1 and the main pipeline 2.

[0026] In this embodiment, the reinforcing plate 5 does not need to be removed after the pullback construction is completed, because the reinforcing plate 5 does not occupy the space of the annular space 3, and the reinforcing plate 5 does not affect the normal use of the outer sleeve 1.

[0027] It should be noted that since the main pipeline 2 is located inside the outer casing 1, and support blocks are installed between the main pipeline 2 and the outer casing 1 every 3-5 meters, most of the weight of the main pipeline 2 is borne by the outer casing 1. Therefore, the pulling force required to synchronously drag the main pipeline 2 is not very large. In this embodiment, the clamping force applied by the top block 15 to the main pipeline 2 is converted into frictional force, which is sufficient to drag the main pipeline 2. Moreover, the greater the dragging force, the greater the clamping force of the top block 15 on the main pipeline 2. In order to improve the clamping strength of the top block 15 on the main pipeline 2 and to prevent the main pipeline 2 from being deformed, an anti-jacking ring 14 is fitted on the outer side of the main pipeline 2. The thickness of the anti-jacking ring 14 is not less than twice the wall thickness of the main pipeline 2. The position of the anti-jacking ring 14 corresponds to that of the top block 15. The anti-jacking ring 14 provides support for the main pipeline 2 on the outer wall. After the back-pulling pipeline construction is completed, the anti-jacking ring 14 can be removed.

[0028] A sealing cylinder 12 is slidably disposed between the main body 7 and the central cylinder 8. One end face of the sealing cylinder 12 can abut against the end face of the outer sleeve 1, thereby forming a seal on the end face of the outer sleeve 1. A spring 11 is disposed between the other end face of the sealing cylinder 12 and the main cylinder. Under the elastic force of the spring 11, the sealing cylinder 12 has a tendency to move closer to the outer sleeve 1. An elastic sealing layer is disposed at the contact point between the sealing cylinder 12 and the outer sleeve 1. The sealing cylinder 12 seals the end face of the outer sleeve 1, preventing soil from entering the outer sleeve 1 and preventing the annular space 3 between the main pipeline 2 and the outer sleeve 1 from being blocked by soil. This ensures that the leakage of the main pipeline 2 can be monitored through the annular space 3 in the future.

[0029] The portion of the tow rod 10 extending beyond the main body 7 is threadedly connected to a limiting nut 9. The end face of the limiting nut 9 abuts against the main body 7. The clamping force of the top block 15 on the main pipeline 2 is locked by the limiting nut 9. Therefore, this application can pause when pulling back the pipeline. When pausing, the limiting nut 9 locks the clamping force, so that the top block 15 still clamps the main pipeline 2.

[0030] A strong magnetic core 13 is provided on the inner side of the drag bar 10 corresponding to the cone part. The top block 15 is made of stainless steel. The strong magnetic core 13 has a strong attraction to the top block 15. When the top block 15 has an inward closing space, the top block 15 can automatically move towards the strong magnetic core 13.

[0031] The outer contour of the main body 7 is tapered, which is more conducive to dragging back.

[0032] In summary, this invention can connect and disconnect with both the outer casing 1 and the main pipeline 2 very quickly, significantly reducing construction workload. After connecting to both the outer casing 1 and the main pipeline 2, the invention simultaneously pulls them back, preventing friction and effectively protecting the anti-corrosion layer from scratches. After the pull-back is complete, the end faces of both the outer casing 1 and the main pipeline 2 remain flat, eliminating the need for cutting and facilitating subsequent construction.

Claims

1. A directional synchronous traversing main pipeline (2) and outer tube (1) return tractor, comprising an outer tube (1), main pipeline (2) and return tractor, wherein the outer tube (1) is fitted over the main pipeline (2), and an annular space (3) is left between the outer tube (1) and the main pipeline (2), characterized in that: The outer wall of the outer sleeve (1) is welded with reinforcing plates (5) at equal intervals along the circumference. The return head includes a main body (7). At the end of the main body (7) near one end of the outer sleeve (1), there are evenly spaced pull rods (6) along the circumference. One end of the pull rod (6) is fixedly connected to the main body (7), and the other end of the pull rod (6) is free. The free end of the pull rod (6) can extend between the two reinforcing plates (5). A limiting plate (4) is provided at the free end of the pull rod (6). The limiting plate (4) can abut against the reinforcing plates (5). The length of the limiting plate (4) is greater than the distance between the two reinforcing plates (5). The limiting plate (4) and the pull rod (6) are connected by a pin. The main body (7) A central cylinder (8) is provided on the inner side of the main pipeline (2). The central cylinder (8) is inserted into the interior of the main pipeline (2). A top block (15) is slidably provided on the radial side of the central cylinder (8). One end of the top block (15) can abut against the inner wall of the main pipeline (2). A drag rod (10) is slidably provided on the axial side of the central cylinder (8). One end of the drag rod (10) passes through the central cylinder (8) and the main body (7) in sequence and extends out of the main body (7). The other end of the drag rod (10) has a cone. The other end of the top block (15) can abut against the cone of the drag rod (10). When the drag rod (10) is dragged outward, the cone pushes the top block (15) out and presses it against the inner wall of the main pipeline (2).

2. The return tractor for directional synchronous crossing of the main pipeline (2) and the outer casing (1) according to claim 1, characterized in that: The outer side of the main pipeline (2) is fitted with a top protection ring (14). The thickness of the top protection ring (14) is not less than twice the wall thickness of the main pipeline (2). The position of the top protection ring (14) corresponds to the top block (15).

3. The return tractor for directional synchronous crossing of the main pipeline (2) and the outer casing (1) according to claim 1, characterized in that: A sealing cylinder (12) is slidably disposed between the main body (7) and the central cylinder (8). One end face of the sealing cylinder (12) can abut against the end face of the outer sleeve (1), thereby forming a seal on the end face of the outer sleeve (1). A spring (11) is disposed between the other end face of the sealing cylinder (12) and the main cylinder. Under the elastic force of the spring (11), the sealing cylinder (12) has a tendency to move closer to the outer sleeve (1).

4. The return tractor for directional synchronous crossing of the main pipeline (2) and the outer casing (1) according to claim 3, characterized in that: An elastic sealing layer is provided at the contact point between the sealing cylinder (12) and the outer sleeve (1).

5. A return tractor for directional synchronous crossing of the main pipeline (2) and the outer casing (1) according to claim 1, characterized in that: The portion of the tow rod (10) extending beyond the main body (7) is threadedly connected to a limiting nut (9), and the end face of the limiting nut (9) abuts against the main body (7).

6. A return tractor for directional synchronous crossing of the main pipeline (2) and the outer casing (1) according to claim 1, characterized in that: A strong magnetic core (13) is provided on the inner side of the drag bar (10) corresponding to the cone part, and the top block (15) is made of stainless steel.

7. A return tractor for directional synchronous crossing of the main pipeline (2) and the outer casing (1) according to claim 1, characterized in that: The outer contour of the main body (7) is conical.

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