Caterpillars type supporting structure for pipe-in-pipe

Abstract

The utility model relates to a caterpillar type supporting structure used for a pipe-in-pipe, which solves the problems that when a large-depth single-well geothermal energy exploration and production well adopts a pipe-in-pipe or hole-in-pipe structure, the supporting and fixing of a central pipe not only need to ensure that the central pipe does not incline or deform, but also need to ensure the requirement of flexible adjustment. The structure comprises an outer pipe and an inner pipe, the inner pipe is arranged in the outer pipe in a penetrating mode, a gap is formed between the outer wall of the inner pipe and the inner wall of the outer pipe, a supporting mechanism is arranged between the outer wall of the inner pipe and the inner wall of the outer pipe and comprises a sleeve arranged on the outer wall of the inner pipe in a sleeving mode, at least three supporting feet are evenly arranged on the periphery of the sleeve, and the outer ends of the supporting feet abut against the inner wall of the outer pipe. Each supporting foot is sequentially provided with a first one-way joint and a second one-way joint from inside to outside, and the swinging directions of the first one-way joints and the second one-way joints are both in the axial direction of the outer pipe and are opposite. Stable supporting is formed in the static state, and when the inner pipe and the outer pipe are drawn relative to the axial direction, the first one-way joint and the second one-way joint can reduce drawing resistance bidirectionally and avoid obstacles.

Description

Technical Field

[0001] This utility model belongs to the field of pipeline engineering and relates to an inner pipe support structure for a double-layer sleeve, particularly a caterpillar-type support structure for pipe-in-pipe. Background Technology

[0002] In the single-well structure for deep geothermal energy exploration and production, the central casing adopts a pipe-in-pipe or borehole-in-pipe structure. That is, a casing for reinforcement is set in the upper part of the well wall in the exploration and production well. The casing depth is 70-90% of the exploration and production well depth. Alternatively, the casing can be set only in the upper soil layer area (not in the rock layer). A central pipe is set in the center of the casing. The wall of the central pipe is equipped with a heat insulation layer. A cold water injection channel is formed between the inner wall of the casing and the outer wall of the central pipe. A hot water rising channel is formed inside the central pipe, forming a closed-loop circulation system.

[0003] In geothermal energy extraction, the depth of exploration wells is often above 4,000 meters, making the support and fixation of the central pipe crucial. This support structure needs to ensure that the central pipe does not tilt or deform during operation, and also ensure that the central pipe does not become an obstacle during descent or lifting, while being able to flexibly adjust its structural form. Utility Model Content

[0004] This invention addresses the challenge of supporting and fixing the central pipe in deep, single-well geothermal exploration wells with pipe-in-pipe or borehole-in-pipe structures. The solution requires ensuring the central pipe remains stable without tilting or deformation while allowing for flexible adjustment. This invention provides a caterpillar-shaped support structure for pipe-in-pipe structures. This structure provides stable support for the central pipe while allowing for flexible adjustment of its height. This device is not limited to pipe-in-pipe structures in geothermal exploration wells; it can also be applied to supporting other pipe-in-pipe or borehole-in-pipe structures at any angle, including vertical, horizontal, and inclined structures.

[0005] The technical solution adopted by this utility model to solve its technical problem is: a caterpillar-shaped support structure for a tube-in-tube, including an outer tube and an inner tube, wherein the inner tube is inserted inside the outer tube, and there is a gap between the outer wall of the inner tube and the inner wall of the outer tube. A support mechanism is provided between the outer wall of the inner tube and the inner wall of the outer tube. The support mechanism includes a sleeve fitted on the outer wall of the inner tube, and at least three legs are evenly arranged around the circumference of the sleeve. The outer ends of the legs abut against the inner wall of the outer tube. The legs are provided with a first one-way joint and a second one-way joint from the inside to the outside. The swing direction of the first one-way joint and the second one-way joint is both towards the axial direction of the outer tube and the swing direction is opposite.

[0006] This structure can be installed between the outer wall of the inner tube and the inner wall of the outer tube in a pipe-in-pipe structure, providing stable support when static. When the inner and outer tubes need to move relative to each other axially, the first or second one-way joint can swing slightly to reduce resistance during movement. When encountering an obstacle, the first or second one-way joint can swing significantly to avoid it, returning to its original position after clearing the obstacle. The outer tube of this structure can be a pipe or a borehole. When this structure is applied to geothermal energy exploration wells in the background technology, the outer tube is the casing of a low-temperature thermal energy exploration well or the well wall without casing, the inner tube is the central tube, the gap between the central tube and the casing is the cold water inlet, and the inner side of the central tube is the hot water outlet.

[0007] Preferably, with the axial direction of the outer tube as the up-down direction, the first one-way joint structure is as follows: the outer wall of the sleeve is hinged to a first swing block through a first hinge shaft, the outer wall of the sleeve is provided with a first limiting block on the upper side of the first swing block, and a first tension spring is provided between the upper side of the first limiting block and the first swing block, the first tension spring pulls the first swing block tightly against the first limiting block.

[0008] Preferably, the second one-way joint structure is as follows: the outer end of the first swing block is hinged to a second swing block via a second hinge shaft; a second limiting block is provided on the lower side of the second swing block at the outer end of the first swing block; a second tension spring is provided between the lower side of the second limiting block and the second swing block, and the second tension spring pulls the second swing block tightly against the first limiting block. The vertical direction of the outer tube can be reversed or placed horizontally without affecting the use of the support structure.

[0009] Preferably, when the first swing block is against the first limiting block, the first swing block is perpendicular to the outer wall of the sleeve; when the second swing block is against the second limiting block, the second swing block and the first swing block are on the same straight line.

[0010] Preferably, the first tension spring is connected to the outer end of the upper side of the first swing block.

[0011] Preferably, the second tension spring is connected to the outer end of the lower side of the second swing block.

[0012] Preferably, the total length of the support leg is adapted to the gap width between the inner and outer tubes.

[0013] Preferably, the outer end of the support leg is an arc-shaped end.

[0014] This utility model is installed between the outer wall of the inner tube and the inner wall of the outer tube in a tube-in-tube structure. When static, it forms a stable support. When the inner tube and the outer tube move axially relative to each other, the first one-way joint and the second one-way joint with opposite swing directions can reduce the moving resistance in both directions and avoid obstacles. Attached Figure Description

[0015] The present invention will be further described below with reference to the accompanying drawings.

[0016] Figure 1 This is a schematic diagram of a single-well structure of a geothermal energy exploration and production well according to this utility model.

[0017] Figure 2 This is a cross-sectional view of the support mechanism between the inner and outer tubes of this utility model.

[0018] Figure 3 This is a side view of the support mechanism of this utility model.

[0019] In the diagram: 1. Soil layer, 2. Hot dry rock layer, 3. Crack, 4. Exploration well, 5. Outer pipe, 6. Inner pipe, 7. Support mechanism, 8. Sleeve, 9. First limiting block, 10. First swing block, 11. First hinge shaft, 12. First tension spring, 13. Second limiting block, 14. Second swing block, 15. Second hinge shaft, 16. Second tension spring, A. First one-way joint, B. Second one-way joint. Detailed Implementation

[0020] The present invention will be further described below with reference to specific embodiments and accompanying drawings.

[0021] Example: A pipe-in-pipe caterpillar-type support structure for geothermal energy single well structures, such as... Figure 1 , 2 As shown. This structure includes an exploration well 4, which extends downwards from the ground through the soil layer 1 to a certain depth in the hot dry rock layer 2. In this example, the exploration well 4 is 4000 meters deep. A casing is installed at the top of the exploration well 4, with its lower end extending to the hot dry rock layer 2. Artificial cracks 3 are created in the hot dry rock layer 2 at the lower end of the casing to facilitate heat exchange. A central pipe passes through the center of the casing, with its lower end lower than the lower end of the casing. In this example, the casing serves as the outer pipe 5 of the pipe-in-pipe structure, and the central pipe serves as the inner pipe 6 of the pipe-in-pipe structure.

[0022] like Figure 1 , 2 As shown, the inner tube 6 passes through the interior of the outer tube 5, and there is a gap between the outer wall of the inner tube 6 and the inner wall of the outer tube 5. A support mechanism 7 is provided between the outer wall of the inner tube 6 and the inner wall of the outer tube 5. Figure 3 As shown, the support mechanism includes a sleeve 8 fitted onto the outer wall of the inner tube. At least three legs are evenly arranged around the circumference of the sleeve. The outer ends of the legs abut against the inner wall of the outer tube. The total length of the legs matches the gap width between the inner and outer tubes, and the outer ends of the legs are arc-shaped. From the inside out, the legs are sequentially equipped with a first one-way joint A and a second one-way joint B. The first one-way joint A and the second one-way joint B swing in the up-down direction but in opposite directions.

[0023] The structure of the first one-way joint A is as follows: A first swing block 10 is hinged to the outer wall of the sleeve 8 via a first hinge shaft 11. A first limiting block 9 is provided on the upper side of the first swing block on the outer wall of the sleeve. A first tension spring 12 is provided between the upper side of the first limiting block and the first swing block. The first tension spring pulls the first swing block tightly against the first limiting block. The first tension spring is connected to the outer end of the upper side of the first swing block.

[0024] The second one-way joint structure is as follows: The outer end of the first swing block 10 is hinged to the second swing block 14 via the second hinge shaft 15. The outer end of the second swing block 14 is an arc-shaped end that abuts against the inner wall of the outer tube. A second limiting block 13 is provided on the lower side of the second swing block 14 at the outer end of the first swing block 10. A second tension spring 16 is provided between the lower side of the second limiting block 13 and the second swing block 14. The second tension spring pulls the second swing block tightly against the first limiting block. The second tension spring is connected to the outer end of the lower side of the second swing block.

[0025] When the first swing block 10 is against the first limiting block 9, the first swing block 10 is perpendicular to the outer wall of the sleeve 8; when the second swing block 14 is against the second limiting block 13, the second swing block 14 and the first swing block 10 are on the same straight line.

[0026] When the supporting structure is static, it forms a stable support, and the first and second one-way joints are deployed. When the inner and outer tubes need to move relative to each other axially, the first or second one-way joint can swing slightly to reduce the resistance during the movement. When encountering an obstacle, the first or second one-way joint can swing significantly to avoid it, and return to its original position after leaving the obstacle.

Claims

1. A caterpillar-shaped support structure for a tube-in-tube configuration, comprising an outer tube and an inner tube, wherein the inner tube passes through the interior of the outer tube, and a gap exists between the outer wall of the inner tube and the inner wall of the outer tube, characterized in that: A support mechanism is provided between the outer wall of the inner tube and the inner wall of the outer tube. The support mechanism includes a sleeve fitted on the outer wall of the inner tube. At least three legs are evenly arranged around the circumference of the sleeve. The outer ends of the legs abut against the inner wall of the outer tube. The legs are provided with a first one-way joint and a second one-way joint from the inside to the outside. The swing direction of the first one-way joint and the second one-way joint is both towards the axial direction of the outer tube and the swing direction is opposite.

2. The caterpillar-shaped support structure for a tube-in-tube as described in claim 1, characterized in that: With the axial direction of the outer tube as the up-down direction, the first one-way joint structure is as follows: the outer wall of the sleeve is hinged to a first swing block through a first hinge shaft, the outer wall of the sleeve is provided with a first limiting block on the upper side of the first swing block, and a first tension spring is provided between the upper side of the first limiting block and the first swing block. The first tension spring pulls the first swing block tightly against the first limiting block.

3. The caterpillar-shaped support structure for a tube-in-tube as described in claim 2, characterized in that: The second one-way joint structure is as follows: the outer end of the first swing block is hinged to the second swing block through the second hinge shaft, the outer end of the first swing block is provided with a second limiting block on the lower side of the second swing block, and a second tension spring is provided between the lower side of the second limiting block and the second swing block. The second tension spring pulls the second swing block tightly against the first limiting block.

4. A caterpillar-shaped support structure for a tube-in-tube as described in claim 3, characterized in that: When the first swing block is against the first limiting block, the first swing block is perpendicular to the outer wall of the sleeve; when the second swing block is against the second limiting block, the second swing block and the first swing block are on the same straight line.

5. A caterpillar-shaped support structure for a tube-in-tube as described in claim 2, characterized in that: The first tension spring is connected to the outer end of the upper side of the first swing block.

6. A caterpillar-shaped support structure for a tube-in-tube as described in claim 3, characterized in that: The second tension spring is connected to the outer end of the lower side of the second swing block.

7. A caterpillar-shaped support structure for a tube-in-tube as described in claim 1, characterized in that: The total length of the support leg is adapted to the gap width between the inner and outer tubes.

8. A caterpillar-shaped support structure for a tube-in-tube as described in claim 1, characterized in that: The outer end of the support leg is arc-shaped.

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