Plastic deformation type shock absorber

Abstract

The invention relates to a plastic deformation type shock absorber which comprises an upper connector, the upper connector is connected with an outer cylinder, a corrugated pipe and a spring are arranged on the inner side of the outer cylinder, a mandrel is arranged on the inner side of the spring, the lower portion of the mandrel is connected with a lower connector, and when the lower connector is subjected to axial impact load, the spring is compressed in a buffering mode, and the corrugated pipe absorbs energy to be broken. A crushable energy absorption element corrugated pipe is used for absorbing perforation detonation impact load, impact fluctuation energy is converted into heat, the impact load is dissipated within a very short time, and damage to other instruments such as packers, instruments, pipe fittings and adjacent perforation gun barrel columns is prevented. The device is reliable in performance, timely in function response and high in impact load absorption capacity; the tool can be repeatedly used, and only the corrugated pipe needs to be replaced.

Description

Technical Field

[0001] This invention relates to the field of oil well completion engineering testing, and more specifically, to a plastic deformation type shock absorber. Background Technology

[0002] Shock absorbers reduce the energy of perforation impact waves by absorbing and dissipating energy, thereby protecting the safety of the tubing and tools. The main types of shock absorbers are: compressible shock absorbers, hydraulic shock absorbers, plastic deformation shock absorbers, and shear shock absorbers.

[0003] During the construction of the three-stage perforation acid fracturing test string, only springs or rubber damping can be used, which is insufficient to meet the requirements. The perforation operation generates large pressure and axial loads instantaneously. The packers, instruments, and other main devices are subjected to the dual impact of vibration load and pressure difference, resulting in structural damage and causing the operation to stop and production to be hindered.

[0004] While existing longitudinal spring dampers offer some energy absorption and vibration reduction, the springs generate rebound force upon compression, leading to a continuous dynamic response in the tubing and a delayed response time. In existing longitudinal rubber dampers, the rubber is susceptible to deformation due to temperature and impact during perforation, causing interference between the rubber sleeve and the tool's outer cylinder, resulting in maintenance difficulties. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a plastic deformation shock absorber that can convert vibration and impact energy into heat, so that the impact load can be dissipated in a very short time, and damage to packers, instruments, pipes and adjacent perforation gun barrels can be prevented.

[0006] The technical solution adopted by the present invention to solve its technical problem is: to construct a plastic deformation shock absorber, including an upper joint, an outer cylinder connected to the upper joint, a bellows and a spring provided inside the outer cylinder, a spindle provided inside the spring, and the lower part of the spindle connected to the lower joint. When the lower joint is subjected to axial impact load, the spring buffers the compression, and the bellows absorbs energy and breaks.

[0007] In the above scheme, the left end of the bellows is provided with a slider, which is in close contact with the bellows under the spring force, and the left end of the bellows, the slider and the inner side of the spring are in clearance fit with the mandrel.

[0008] In the above scheme, a seal is provided between the outer side of the mandrel and the lower connector.

[0009] In the above scheme, the upper connector and the outer cylinder are connected by set screws.

[0010] In the above scheme, a connecting sleeve is fitted to the outer side of the lower connector with a clearance, and the connecting sleeve is connected to the outer cylinder by a thread.

[0011] In the above scheme, the lower connector is connected to the outer cylinder by a shear pin.

[0012] In the above scheme, the outer cylinder is provided with multiple pressure transmission holes.

[0013] The plastic deformation shock absorber of the present invention has the following beneficial effects:

[0014] This invention utilizes a crushable energy-absorbing bellows element to absorb the impact load of perforation detonation, converting the impact wave energy into heat, allowing the impact load to dissipate in a very short time and preventing damage to other equipment such as packers, instruments, pipes, and adjacent perforation gun barrels. This invention is reliable, has a timely functional response, and a strong ability to absorb impact loads; the tool is reusable multiple times, requiring only the replacement of the bellows. Attached Figure Description

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

[0016] Figure 1 This is a schematic diagram of the structure of the plastic deformation type shock absorber of the present invention;

[0017] Figure 2 This is a schematic diagram of the bellows structure;

[0018] Figure 3 This is a schematic diagram of a spring. Detailed Implementation

[0019] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0020] like Figure 1-3 As shown, the upper connector 1 of the plastic deformation shock absorber of the present invention is connected to an outer cylinder 7. A bellows 3 and a spring 5 are provided inside the outer cylinder 7. A spindle 6 is provided inside the spring 5. The lower part of the spindle 6 is connected to the lower connector 11. The bellows 3 is a plastic energy-absorbing element.

[0021] The upper connector 1 is threadedly connected to an outer cylinder 7, and a bellows 3 is fitted inside the outer cylinder 7 with a clearance fit. A slider 4 is located at the left end of the bellows 3, and the slider 4 is tightly attached to the energy-absorbing bellows 3 under the elastic force of a spring 5. A mandrel 6 is fitted inside the bellows 3, slider 4, and spring 5 with a clearance fit. A sealing element 9 is located on the outside of the mandrel 6, forming a sealing fit with the lower connector 11. A connecting sleeve 10 is fitted on the outside of the lower connector 11 with a clearance fit, and it is threadedly connected to the outer cylinder 7.

[0022] The outer cylinder 7 is equipped with several pressure transmission holes and 8 screw holes, with shear pins 8 installed in the screw holes. The pressure transmission holes can discharge pressurized fluid in a timely manner, preventing structural damage due to excessive internal pressure.

[0023] This invention transmits and receives axial impact kinetic energy through the lower connector 11. When the force exceeds the rated value, the shear pin 8 is sheared. Then, the lower connector 11 continues to move axially and begins to compress the spring 5. The compression of the spring 5 provides a certain buffering effect. Subsequently, the spring 5 continues to compress and begins to crush the bellows 3. The bellows 3 begins to break and absorb the remaining perforation detonation impact load, converting the impact wave energy into heat. Ultimately, the impact load is dissipated in a very short time, preventing damage to other equipment such as packers, instruments, pipes, and adjacent perforation gun barrels.

[0024] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A plastic deformation shock absorber characterized by, The upper joint is connected with an outer cylinder, the inner side of the outer cylinder is provided with a bellows and a spring, the inner side of the spring is provided with a mandrel, the lower part of the mandrel is connected with a lower joint, when the lower joint is subjected to an axial impact load, the spring is compressed to buffer, and the bellows absorbs energy to break.

2. The plastic deformation shock absorber of claim 1, wherein The left end of the bellows is provided with a sliding block, the sliding block is tightly attached to the bellows under the spring elastic force, the left end of the bellows, the sliding block and the inner side of the spring are gap-fitted with the mandrel.

3. The plastic deformation shock absorber of claim 1, wherein, The outer side of the mandrel is provided with a sealing element between the mandrel and the lower joint.

4. The plastic deformation shock absorber of claim 1, wherein The upper joint is connected with the outer cylinder through a set screw.

5. The plastic deformation shock absorber of claim 1, wherein, The outer side of the lower joint is gap-fitted with a connecting sleeve, the connecting sleeve is connected to the outer cylinder through a thread.

6. The plastic deformation shock absorber of claim 1, wherein The lower joint is connected with the outer cylinder through a shear pin.

7. The plastic deformation shock absorber of claim 1, wherein The outer cylinder 7 is provided with a plurality of pressure transmission holes.

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