Corrugated steel energy-absorbing shock absorber

Abstract

The invention relates to a corrugated steel energy-absorbing shock absorber which comprises a first connecting part, an outer cylinder, a mandrel, a corrugated steel energy-absorbing element, a second connecting part and an end cap. The first connecting part is detachably connected to the axial left end of the outer cylinder, and the outer cylinder is detachably connected to the axial left end of the end cap; the two axial ends of the mandrel are matched with the first connecting part and the second connecting part respectively. The mandrel is arranged in an inner cavity of the outer cylinder and detachably connected to the right end of the first connecting part, and the corrugated steel energy absorption element is arranged between the inner cavity of the outer cylinder and the outer side of the mandrel. By means of the corrugated steel energy absorption shock absorber, impact loads generated by perforation detonation can be absorbed in the deformation process of corrugated steel, and therefore a tubular column and a tool are protected.

Description

Technical Field

[0001] The invention relates to a downhole tool for perforation testing in an oil testing and well completion project, and more particularly to a shock absorber. Background Art

[0002] Shock absorbers are key downhole tools in perforating and testing operations. The shock loads generated by perforating explosions are offset and mitigated by shock absorbers to protect the tubing and tools. As exploration moves toward ultra-deep layers, the impact of perforating explosions on tubing begins to rise sharply. The impact loads generated by perforating explosions can have a strong impact and damage effect on tubing and downhole tools, which can easily lead to various failure accidents, such as tubing breakage and deformation. Especially for the complex operating environment of deep and ultra-deep wells, the risk of safety accidents in perforating and testing operations is bound to increase greatly, causing huge economic losses. In actual on-site perforating and testing operations, shock absorbers are often needed to reduce the impact and damage of perforating.

[0003] Most of the longitudinal shock absorbers currently in use use spring shock absorption. The spring has poor energy absorption effect and the shock absorption effect cannot meet the requirements. In addition, the spring in the spring shock absorber will produce rebound force after compression, resulting in a continuous dynamic response process in the column and poor shock absorption effect. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a corrugated steel energy-absorbing shock absorber to replace the spring shock absorber to solve the problem that the impact load generated by the perforating explosion will cause strong impact damage to the pipe string and downhole tools, which is easy to cause various failure accidents. The present invention can absorb the impact load generated by the perforating explosion through the deformation process of the corrugated steel. Conventional shock absorbers use a spring structure to convert the generated impact kinetic energy into spring elastic potential energy, and the elastic potential energy is converted into impact kinetic energy, which repeatedly acts on the perforating pipe string.

[0005] The technical solution adopted by the present invention to solve the technical problem is: construct a corrugated steel energy absorbing shock absorber, including a first connecting component, an outer cylinder, a core shaft, a corrugated steel energy absorbing element, a second connecting component and an end cap;

[0006] The first connecting component is detachably connected to the axial left end of the outer cylinder, the outer cylinder is detachably connected to the axial left end of the end cap, the first connecting component has a through hole allowing fluid to flow, the second connecting component cooperates with the outer cylinder and the core shaft, and is limited by the end cap, the second connecting component has a through hole allowing fluid to flow; the core shaft cooperates with the first connecting component and the second connecting component along the axial ends respectively;

[0007] The core shaft is arranged in the inner cavity of the outer cylinder, and its axis is parallel to the axis of the outer cylinder, and is detachably connected to the right end of the first connecting component. The core shaft has a through hole allowing fluid to flow. The corrugated steel energy absorbing element is arranged between the inner cavity of the outer cylinder and the outer side of the core shaft, and its axis is parallel to the axes of the outer cylinder and the core shaft. The two ends of the corrugated steel energy absorbing element are respectively fixed to the right end of the first connecting component and the left end of the second connecting component.

[0008] According to the above solution, a first positioning screw connection is further provided between the first connecting component and the outer tube, and the first positioning screw passes through the first connecting component and abuts against the surface of the second fixing portion.

[0009] According to the above solution, a groove is provided on the right side of the first connecting component, which cooperates with the corrugated steel energy absorbing element through the groove and is fixedly connected by a second positioning screw.

[0010] According to the above solution, a groove is provided on the left side of the second connecting component, which cooperates with the corrugated steel energy absorbing element through the groove and is fixedly connected by the third positioning screw.

[0011] According to the above scheme, drainage holes evenly distributed are provided on the outer wall of the second connecting component. When the second connecting component moves upward under the influence of the shock wave to compress the corrugated steel energy absorbing element, the excess material generated by the upward movement of the second connecting component to compress the cavity is discharged through the drainage holes.

[0012] According to the above scheme, the core shaft includes a first sealing section, the outer contour of the first sealing section is a columnar body whose axis is parallel to the axis of the core shaft. When the first connecting component is connected to the core shaft, the first seal is located inside the first connecting component, and a first sealing component is arranged between the first sealing section and the inner wall of the first connecting component to seal the gap between the first sealing section and the inner wall of the first connecting component.

[0013] According to the above scheme, the core shaft includes a second sealing section, the outer contour of the second sealing section is a columnar body whose axis is parallel to the axis of the core shaft. When the second connecting component is connected to the core shaft, the second seal is located inside the second connecting component, and a second sealing component is arranged between the second sealing section and the inner wall of the second connecting component to seal the gap between the second sealing section and the inner wall of the second connecting component.

[0014] According to the above solution, a first starting pin is provided between the lower outer cylinder and the second connecting component. The first starting pin passes through the lower outer cylinder and abuts against the groove of the second connecting component.

[0015] The corrugated steel energy absorbing shock absorber of the present invention has the following beneficial effects:

[0016] The present invention utilizes plastic deformation energy absorbing elements to absorb the impact load of perforation explosion, and absorbs the impact wave energy through the deformation process of corrugated steel. When the impact load is transmitted to the shock absorber, the second connecting component of the shock absorber moves upward under the influence of the shock wave, cuts off the start pin, and the corrugated steel energy absorbing element begins to work. In the process of continuous compression of the corrugated steel energy absorbing element, the impact wave energy is absorbed, so that the impact load is dissipated in a very short time, and no rebound force is generated. There is no continuous dynamic response process in the pipe string, so as to achieve the purpose of protecting the safety of the pipe string and tools. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0018] Figure 1 A schematic diagram of the internal structure of the corrugated steel energy absorbing shock absorber of the present invention;

[0019] Figure 2 is a cross-sectional view of a corrugated steel energy absorbing element;

[0020] In the figure: 1 first connecting component; 1-1 first connecting end; 1-2 second fixing part; 2 outer cylinder; 2-1 second connecting end; 2-2 third connecting end; 3 core shaft; 3-1 first fixing part; 3-2 first sealing section; 3-3 first positioning groove; 3-4 second sealing section; 3-5 second positioning groove; 4 corrugated steel energy absorbing element; 5 second connecting component; 6 end cap; 6-1 third fixing part; 31 first positioning screw; 32 second positioning screw; 33 third positioning screw; 34 first starting pin; 41 first sealing component; 42 second sealing component. DETAILED DESCRIPTION

[0021] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0022] like Figure 1-2 As shown, the corrugated steel energy absorbing shock absorber of the present invention utilizes plastic deformation energy absorbing elements to absorb the impact load of perforation explosion. When the impact load is transmitted to the shock absorber, the second connecting component 5 of the shock absorber moves upward under the influence of the shock wave, cuts off the start pin, and the corrugated steel energy absorbing element 4 begins to work. In the process of continuous compression of the corrugated steel energy absorbing element 4, the impact wave energy is absorbed, so that the impact load is dissipated in a very short time to achieve the purpose of protecting the safety of the pipe string and tools.

[0023] The corrugated steel energy absorbing shock absorber of the present invention comprises a first connecting component 1 , an outer cylinder 2 , a core shaft 3 , a corrugated steel energy absorbing element 4 , a second connecting component 5 and an end cap 6 .

[0024] The first connecting component 1 is detachably connected to the axial left end of the outer cylinder 2, and the outer cylinder 2 is detachably connected to the axial left end of the end cap 6. The first connecting component 1 has a through hole allowing fluid to flow. The second connecting component 5 cooperates with the outer cylinder 2 and the core shaft 3, and is limited by the end cap 6. The second connecting component 5 has a through hole allowing fluid to flow.

[0025] The core shaft 3 is arranged in the inner cavity of the outer cylinder 2, and its axis is parallel to the axis of the outer cylinder 2, and is detachably connected to the right end of the first connecting component 1. The core shaft 3 has a through hole allowing fluid to flow. The corrugated steel energy absorbing element 4 is arranged between the inner cavity of the outer cylinder 2 and the outside of the core shaft 3, and its axis is parallel to the axes of the outer cylinder 2 and the core shaft 3. It is connected to the right end of the first connecting component 1 through a second positioning screw 32 and is connected to the left end of the second connecting component 5 through a third positioning screw 33.

[0026] A groove is provided on the right side of the first connecting component 1 , which cooperates with the corrugated steel energy absorbing element 4 through the groove and is connected through the second positioning screw 32 .

[0027] The corrugated steel energy absorbing element 4 is made of a specific material, and utilizes the material properties and special structure of the corrugated steel energy absorbing element 4 to absorb the perforation detonation impact load through plastic deformation.

[0028] A groove is provided on the left side of the second connecting component 5 , which cooperates with the corrugated steel energy absorbing element 4 through the groove and is connected through the third positioning screw 33 .

[0029] Evenly distributed drainage holes are provided on the outer wall of the second connecting component 5. The second connecting component 5 moves upward under the influence of the shock wave to compress the corrugated steel energy absorbing element 4. The excess material generated by the upward movement of the second connecting component 5 in the compressed cavity can be discharged along the evenly distributed drainage holes to prevent the corrugated steel energy absorbing element 4 from being affected by plastic deformation and absorbing the perforation detonation impact load.

[0030] The core shaft 3 cooperates with the first connecting component 1 and the second connecting component 5 at both ends along the axial direction respectively; the core shaft 3 includes a first sealing section 3-2, the outer contour of the first sealing section 3-2 is a columnar body whose axis is parallel to the axis of the core shaft 3. When the first connecting component 1 is connected to the core shaft 3, the first seal 3-2 is located inside the first connecting component 1, and a first sealing component 41 is arranged between the first sealing section 3-2 and the inner wall of the first connecting component 1 to seal the gap between the first sealing section 3-2 and the inner wall of the first connecting component 1.

[0031] The core shaft 3 includes a second sealing section 3-4, the outer contour of the second sealing section 3-4 is a columnar body whose axis is parallel to the axis of the core shaft 3. When the second connecting component 5 is connected to the core shaft 3, the second seal 3-4 is located inside the second connecting component 5, and a second sealing component 42 is arranged between the second sealing section 3-4 and the inner wall of the second connecting component 5 to seal the gap between the second sealing section 3-4 and the inner wall of the second connecting component 5.

[0032] The left end of the mandrel 3 cooperates with the first connecting member 1. The mandrel 3 includes a first fixing portion 3-1, on which an external thread is arranged, and an internal thread matching the external thread on the first fixing portion 3-1 is arranged on the inner wall of the first connecting end 1-1, and the mandrel 3 is threadedly connected to the first connecting end 1-1 through the first fixing portion 3-1;

[0033] The two ends of the outer cylinder 2 along the axial direction are respectively the second connection end 2-1 and the third connection end 2-2. The first connection component 1 includes a second fixing portion 1-2, on which an external thread is arranged, and an internal thread matching the external thread on the second fixing portion 1-2 is arranged on the inner wall of the second connection end 2-1, and the first connection component 1 is threadedly connected to the second connection end 2-1 through the second fixing portion 1-2.

[0034] The end cap 6 includes a third fixing portion 6-1, on which an external thread is arranged, and an internal thread matching the external thread on the third fixing portion 6-1 is arranged on the inner wall of the third connecting end 2-2, and the end cap 6 is threadedly connected to the third connecting end 2-2 through the third fixing portion 6-1.

[0035] The corrugated steel energy absorbing shock absorber also includes a first positioning screw 31. A first positioning screw hole extending radially along the outer tube 2 and matching the first positioning screw 31 is provided on the side wall of the second connecting end 2-1. The first positioning screw 31 is threadedly connected in the first positioning screw hole and can abut against the surface of the second fixing part 1-2.

[0036] The corrugated steel energy absorbing shock absorber also includes a second positioning screw 32. A second positioning screw hole extending radially along the first connecting component 1 and matching the second positioning screw 32 is provided on the side wall at the right end of the first connecting component 1. The second positioning screw 32 is threadedly connected in the second positioning screw hole and connects the corrugated steel energy absorbing element 4 to the first connecting component 1.

[0037] The corrugated steel energy absorbing shock absorber also includes a third positioning screw 33. A third positioning screw hole extending radially along the second connecting component 5 and matching the third positioning screw 33 is provided on the side wall at the left end of the second connecting component 5. The third positioning screw 33 is threadedly connected in the third positioning screw hole and connects the corrugated steel energy absorbing element 4 with the second connecting component 5.

[0038] The corrugated steel energy absorbing shock absorber also includes a first starting pin 34. A fourth positioning screw hole is provided on the side wall of the third connecting end 2-2, extending radially along the lower outer tube 2 and matching the first starting pin 34. The first starting pin 34 is threadedly connected in the fourth positioning screw hole and can abut against a specific groove of the second connecting component 5.

[0039] A first positioning groove 3-3 extending in the circumferential direction is provided on the outer wall of the first sealing section 3-2, and the first sealing component 41 is at least partially located in the first positioning groove 3-3. A second positioning groove 3-5 extending in the circumferential direction is provided on the outer wall of the second sealing section 3-4, and the second sealing component 42 is at least partially located in the second positioning groove 3-5.

[0040] Reference Figure 1 The two ends of the mandrel are provided with sealing components, which can be O-shaped rubber rings in actual production and are sleeved on the sealing section. A positioning groove extending along the circumferential direction is provided on the outer wall of the sealing section, and the sealing component is at least partially located in the positioning groove, so that the stability of the installation of the sealing component and the accuracy of the installation position can be ensured.

[0041] Reference Figure 2 The corrugated steel energy absorbing element is made of specific materials and utilizes the material properties and special structure of the corrugated steel energy absorbing element to absorb the perforation detonation impact load through plastic deformation.

[0042] The impact load generated by the perforating explosion will have a strong impact and destructive effect on the tubing and downhole tools, which may easily lead to various failure accidents, such as tubing breakage and deformation. Especially for the complex operating environment of deep wells and ultra-deep wells, the risk of safety accidents in the perforating test operation will inevitably increase greatly, causing huge economic losses. Conventional shock absorbers use a spring structure to convert the generated impact kinetic energy into spring elastic potential energy, which in turn is converted into impact kinetic energy, which repeatedly acts on the perforating tubing and causes damage to the tubing and tools. The present invention can absorb the impact load generated by the perforating explosion through the deformation process of corrugated steel to protect the tubing and tools.

[0043] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A corrugated steel energy absorbing shock absorber, characterized in that: It comprises a first connecting component (1), an outer cylinder (2), a core shaft (3), a corrugated steel energy absorbing element (4), a second connecting component (5) and an end cap (6); The first connecting component (1) is detachably connected to the axial left end of the outer cylinder (2), and the outer cylinder (2) is detachably connected to the axial left end of the end cap (6). The first connecting component (1) has a through hole allowing fluid to flow. The second connecting component (5) cooperates with the outer cylinder (2) and the core shaft (3) and is limited by the end cap (6). The second connecting component (5) has a through hole allowing fluid to flow. The core shaft (3) cooperates with the first connecting component (1) and the second connecting component (5) at both ends along the axial direction. The core shaft (3) is arranged in the inner cavity of the outer cylinder (2), and its axis is parallel to the axis of the outer cylinder (2), and is detachably connected to the right end of the first connecting component (1). The core shaft (3) has a through hole that allows fluid to flow. The corrugated steel energy absorbing element (4) is arranged between the inner cavity of the outer cylinder (2) and the outer side of the core shaft (3), and its axis is parallel to the axes of the outer cylinder (2) and the core shaft (3). The two ends of the corrugated steel energy absorbing element (4) are respectively fixed to the right end of the first connecting component (1) and the left end of the second connecting component (5).

2. The corrugated steel energy absorbing shock absorber according to claim 1, characterized in that: A first positioning screw (31) is also provided between the first connecting component (1) and the outer cylinder (2), and the first positioning screw (31) passes through the first connecting component (1) and abuts against the surface of the second fixing portion (1-2).

3. The corrugated steel energy absorbing shock absorber according to claim 1, characterized in that: The first connecting component (1) is provided with a groove on the right side, which cooperates with the corrugated steel energy absorbing element (4) through the groove and is fixedly connected by a second positioning screw (32).

4. The corrugated steel energy absorbing shock absorber according to claim 1, characterized in that: The second connecting component (5) is provided with a groove on the left side, which cooperates with the corrugated steel energy absorbing element (4) through the groove and is fixedly connected by the third positioning screw (33).

5. The corrugated steel energy absorbing shock absorber according to claim 1, characterized in that: The outer wall of the second connecting component (5) is provided with drainage holes which are evenly distributed. When the second connecting component (5) moves upward under the influence of the shock wave to compress the corrugated steel energy absorbing element (4), the material in the cavity compressed by the upward movement of the second connecting component (5) is discharged through the drainage holes.

6. The corrugated steel energy absorbing shock absorber according to claim 1, characterized in that: The core shaft (3) comprises a first sealing section (3-2), the outer contour of the first sealing section (3-2) is a columnar body whose axis is parallel to the axis of the core shaft (3); when the first connecting component (1) is connected to the core shaft (3), the first seal (3-2) is located inside the first connecting component (1); a first sealing component 41 is provided between the first sealing section (3-2) and the inner wall of the first connecting component (1) for sealing the gap between the first sealing section (3-2) and the inner wall of the first connecting component (1).

7. The corrugated steel energy absorbing shock absorber according to claim 1, characterized in that: The core shaft (3) comprises a second sealing section (3-4), the outer contour of the second sealing section (3-4) is a columnar body whose axis is parallel to the axis of the core shaft (3); when the second connecting component (5) is connected to the core shaft (3), the second seal (3-4) is located inside the second connecting component (5); a second sealing component (42) is provided between the second sealing section (3-4) and the inner wall of the second connecting component (5) for sealing the gap between the second sealing section (3-4) and the inner wall of the second connecting component (5).

8. The corrugated steel energy absorbing shock absorber according to claim 1, characterized in that: A first starting pin (34) is provided between the lower outer cylinder (2) and the second connecting component (5). The first starting pin (34) passes through the lower outer cylinder (2) and abuts against a groove of the second connecting component (5).

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