A gas well injection and production string damping sub and method
By designing a bidirectional vibration damping device that combines axial and radial vibrations, the vibration problem of gas well injection and production tubing under complex operating conditions was solved, achieving efficient absorption of vibrations of different frequencies and directions, and improving the safety and efficiency of production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- YANCHANG OIL FIELD
- Filing Date
- 2025-12-11
- Publication Date
- 2026-06-12
AI Technical Summary
The existing gas well injection and production tubing lacks effective vibration reduction equipment under complex operating conditions, which leads to fatigue loosening of connecting threads and wear of downhole tools due to vibration, affecting production safety and efficiency.
A vibration damping short section for gas well injection and production tubing is designed, employing a bidirectional vibration damping device that includes an upper axial damping spring, a middle axial damping spring, and a radial damping spring. Through trapezoidal thread connection and interference fit, it achieves the absorption of vibration energy of different frequencies and directions.
It significantly improves the stability and reliability of the tubing system under complex working conditions, reduces vibration amplitude and frequency, extends the service life of downhole tools, and improves production safety and efficiency.
Smart Images
Figure CN122190634A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of injection and production tubing technology, and particularly to a vibration-damping short section and method for gas well injection and production tubing. Background Technology
[0002] Complex operating conditions can cause fatigue failure of injection and production tubing under low stress, leading to problems such as accelerated tubing fatigue failure, joint wear, thread loosening, and wellbore integrity, which directly affect the reliability and safety of production.
[0003] In complex production processes, vibration dampers often need to possess special properties such as rapid response and efficient vibration absorption. This requires vibration dampers to maintain high strength and high stability while also having good durability and adaptability.
[0004] Under different operating conditions, there are certain situations where it is necessary to repeatedly install vibration dampers or place vibration dampers in different positions within the injection and production tubing. In different situations, the structure of the vibration damper needs to be adjusted to ensure that it can be installed into the injection and production tubing and is compatible with various production conditions during well testing and completion.
[0005] However, at present, there is a lack of dedicated vibration reduction equipment in gas well injection and production tubing, making it difficult to simultaneously balance production efficiency and structural performance degradation caused by vibration in actual production.
[0006] For example, under the continuous impact of multiphase flow, severe vibration of the tubing string can lead to fatigue and loosening of the connecting threads, and in severe cases, may cause tubing string breakage or disengagement, resulting in huge economic losses and safety risks. Furthermore, vibration accelerates the wear of downhole tools such as safety valves and packers, shortening their service life and increasing the frequency and cost of well workover operations. Effectively increasing tubing string stability can significantly reduce the amplitude and frequency of vibration during production. Summary of the Invention
[0007] In order to overcome the shortcomings of the existing technology, the purpose of this invention is to provide a vibration reduction short section and method for gas well injection and production tubing, which improves the injection and production tubing under complex operating conditions such as multiphase flow, formation pressure fluctuations, and pump start-up and shutdown, and has a high vibration absorption rate and long-term service capability.
[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A vibration damping short section for gas well injection and production tubing includes an upper connector 1, an outer shell intermediate connector 2, and a radially damping outer end shell 9, which are axially connected and fixed by trapezoidal threads to form the main frame of the system. A central tube 8 passes through the interior of the main frame of the system. An upper axial damping spring 6 and a middle axial damping spring 7 are coaxially sleeved on the outer wall of the central tube 8. The ends of the two springs abut against the retaining ring 5 at the bottom of the upper connector 1 and the top of the outer shell intermediate connector 2, respectively, to form an axial graded vibration damping system. The retaining ring 5 is located at the lower end of the upper connector 1.
[0009] The upper connector 1 is a thick-walled tubular component with a standard connecting thread on the top. Its upper end is in the shape of a standard API threaded connector, used to connect with the main body of the gas well injection and production tubing. The interior is a hollow channel, and the lower end of the inner wall is machined with an internal trapezoidal thread for screwing with the external thread of the intermediate connector 2 of the outer shell. At the bottom of the hollow channel, a groove is also machined for placing the retaining ring 5 to provide support for the upper axial damping spring 6.
[0010] The intermediate connecting piece 2 of the outer shell is a double-ended threaded tubular connecting piece used to connect the upper connector 1 and the radial vibration damping outer shell 9 respectively. The outer wall of its upper end is machined with external threads for screwing into the internal threads of the upper connector 1, and the inner wall of its lower end is machined with internal threads for connecting the radial vibration damping outer shell 9. The top end face of the intermediate connecting piece 2 of the outer shell is a flat annular surface, which serves as the support surface for the central axial vibration damping spring 7.
[0011] The radial damping outer end housing 9 is the longest and most complex of the three components, serving as the main housing for the entire radial damping system. It is shaped like a thick-walled tube, with external threads machined on its upper outer wall for connection to the internal threads of the intermediate connecting piece 2 of the outer housing. Its internal cavity has a much larger diameter than the other two components, and its inner wall is machined with precise steps and positioning surfaces for mounting and securing the radial damping system. The central tube 8 is a stepped hollow shaft that runs through the main frame of the system. The upper end is provided with an API standard thread for connecting to the injection and production tubing. The tube body is provided with multiple steps of different outer diameters, which are used to install and position the upper axial damping spring 6, the middle axial damping spring 7, the damping sleeve 15, and the inner ring of the bearing 16, respectively. The shoulders of the steps provide axial support for the relevant components.
[0012] The upper axial damping spring 6 is fitted on the step with a smaller outer diameter on the upper section of the central tube 8. Its axial position is limited between the retaining ring 5 at the bottom of the upper connector 1 and one of the upward steps of the central tube 8 itself. The middle axial damping spring 7 is fitted on the step with a larger outer diameter in the middle section of the central tube 8. Its axial position is limited between the top of the intermediate connector 2 of the outer housing and another upward step of the central tube 8 itself. The retaining ring 5 is installed at the bottom inside the upper connector 1.
[0013] The radial vibration damping system includes a locking cylinder 18, a bearing 16, and a fixing ring 12. The locking cylinder 18, bearing 16, and fixing ring 12 are integrated and assembled inside the radial vibration damping outer end housing 9. The locking cylinder 18 is fixedly installed inside the outer end housing 9. The fixing ring 12 is pressed into the inner wall of the locking cylinder 18 by an interference fit. A bearing end cap 10 is provided at the open end of the locking cylinder 18. The bearing end cap 10 is locked by a positioning screw 11 passing through itself and threaded holes on the fixing ring 12, thus firmly bringing the fixing ring 12 and the locking cylinder 18 together.
[0014] The outer ring of the bearing 16 is clearance-fitted with the inner wall of the locking cylinder 18, while its inner ring is interference-fitted with the central tube 8. The damping sleeve 15 is fitted onto the outer wall of the central tube 8. Multiple sets of radial damping springs 13 and radial spring plungers 14 are arranged in a circumferential array and placed between the locking cylinder 18 and the damping sleeve 15. One end of the spring plunger 14 elastically abuts against the outer wall of the damping sleeve 15 under the elastic force of the spring 13, thereby achieving radial buffering and damping of the central tube 8.
[0015] The positioning screw 11 passes through the bearing end cover 10 and is threadedly locked to the retaining ring 12. The retaining ring 12 is pressed into the inner wall of the locking cylinder 18 through an interference fit, forming a rigid support and positioning function for the radial system. The bearing 16 is an angular contact ball bearing, with its inner ring having an interference fit with the central tube 8 and its outer ring having a clearance fit with the locking cylinder 18, ensuring axial positioning and radial floating freedom.
[0016] The mating surfaces of the radial vibration damping outer end housing 9 and the intermediate connecting part 2 of the outer housing are connected by trapezoidal threads to ensure the sealing performance and fatigue resistance of the housing connection.
[0017] Both the upper connector 1 and the central tube 8 are provided with API threads at their ends for quick adaptation and installation with the gas well injection and production tubing.
[0018] The mating surfaces of the radial vibration damping outer end housing 9 and the intermediate connecting part 2 of the outer housing are connected by trapezoidal threads with a thread profile angle of 30° and a pitch of 3mm.
[0019] A sealing ring 4 is provided between the upper connector 1 and the retaining ring 5, and an O-ring 17 is provided between the lower end cover 10 and the locking cylinder 18.
[0020] A method for using a vibration-damping short section for gas well injection and production tubing includes the following steps: When dealing with axial vertical vibration, the vertical movement of the central tube 8 is buffered by two sets of upper axial damping springs 6 and middle axial damping springs 7 with different stiffnesses. The retaining ring 5 provides a stable support reaction surface for the spring, realizing graded and efficient absorption of vibrations of different frequencies. When dealing with radial horizontal impact, the lateral swing of the central tube 8 will drive the damping sleeve 15, which in turn squeezes the radial spring plunger 14 and radial damping spring 13 arranged in a circumferential array. This process not only achieves the first stage of buffering through the compression of the spring, but also utilizes the damping layer on the damping sleeve 15 to convert vibration energy into heat energy dissipation, thus achieving the second stage of damping energy absorption.
[0021] The beneficial effects of this invention are: This invention proposes a composite vibration damping device with both radial and axial bidirectional vibration reduction functions. This device utilizes a carefully designed dual-function damping unit, comprising a main damping element and an auxiliary damping element, which work synergistically with an interference fit to effectively absorb vibration energy in both the radial and axial directions of the tubular system. The main damping element refers to an elastic element that directly absorbs and buffers vibration energy; specifically, in this invention, it refers to the upper axial damping spring 6, the middle axial damping spring 7, and the radial damping spring 13. They counteract and absorb axial and radial impact vibrations through their own compression and rebound. The auxiliary damping element, namely the damping sleeve 15, mainly works in conjunction with the main damping element to dissipate vibration energy through a damping effect.
[0022] This invention significantly enhances the vibration reduction performance of the device against radial deformation and axial tension through component layout and mechanical design, thereby greatly improving the stability and reliability of the tubing system in complex operating environments and ensuring the safety and efficiency of oil and gas extraction operations.
[0023] This invention significantly improves the smoothness of injection and production tubing vibration under complex conditions through the synergistic action of a dual system: axially graded absorption of vertical vibration and radially multi-stage suppression of lateral impact. The axial damping system consists of an upper axial damping spring 6 and a middle axial damping spring 7. Both are coaxially mounted on the outer wall of the central tube 8, located between the upper connector 1 and the intermediate connecting piece 2 of the outer shell, respectively. The two springs are designed with different stiffnesses: 60 N / mm and 40 N / mm. When the tubing experiences vertical axial vibration: for high-frequency, high-intensity impacts, the stiffer spring 6 responds preferentially and compresses, rapidly absorbing most of the impact energy. For low-frequency, large-amplitude vibrations, the less stiff spring 7 is more easily compressed, effectively suppressing low-frequency vibrations. This gradient stiffness configuration achieves graded and efficient absorption of vibrations in different frequency ranges.
[0024] The radial vibration damping system consists of radial damping springs 13 arranged in a circumferential array, radial spring plungers 14, and damping sleeves 15. When the tubing is subjected to a lateral impact load, causing the central tube 8 to oscillate radially: the central tube 8 moves along with the external damping sleeves 15, compressing one or more radial spring plungers 14 in the impact direction. The plungers 14 transmit the impact force to the radial damping springs 13, compressing the springs and absorbing the impact kinetic energy—this is the first stage of buffering. Simultaneously, the end of the plunger 14 is embedded in the polyurethane damping layer on the inner wall of the damping sleeve 15. During the compression process, the damping material deforms and generates a damping effect, converting vibration energy into heat energy for dissipation—this is the second stage of suppression. Through the elastic buffering of the springs and the energy dissipation of the damping layer, the radial oscillation of the central tube 8 is suppressed, preventing it from rigidly colliding with the outer shell.
[0025] The axial spring stiffness gradient configuration and the radial spring plunger circumferential array layout support quick adjustment and installation according to requirements, with strong adaptability; the trapezoidal threaded housing, threaded locking ring and interference fit bearing provide multiple guarantees for the system's fatigue resistance and loosening resistance under extreme working conditions. Attached Figure Description
[0026] Figure 1 This is a schematic diagram of the vibration reduction short section of the gas well injection and production tubing of the present invention.
[0027] Figure 2 This is a schematic diagram of the outer shell assembly of the present invention.
[0028] Figure 3 This is an enlarged schematic diagram of the central tube structure of the present invention.
[0029] In the diagram: 1. Upper connector; 2. Intermediate connecting piece of outer housing; 4. Sealing structure; 5. Retaining ring; 6. Upper axial damping spring; 7. Middle axial damping spring; 8. Central tube; 9. Radial damping outer end housing; 10. Bearing end cover; 11. Positioning screw; 12. Retaining ring; 13. Radial damping spring; 14. Radial spring plunger; 15. Damping sleeve; 16. Bearing; 17. O-ring seal; 18. Compression cylinder. Detailed Implementation
[0030] The present invention will now be described in further detail with reference to the accompanying drawings.
[0031] like Figure 1-3As shown, a vibration damping short section for gas well injection and production tubing includes an upper connector 1, an outer shell intermediate connector 2, and a radial vibration damping outer end shell 9. The upper connector 1, the outer shell intermediate connector 2, and the radial vibration damping outer end shell 9 are sequentially axially connected and fixed by trapezoidal threads to form the main frame of the system. A central tube 8 passes through the interior of the main frame of the system. An upper axial vibration damping spring 6 and a middle axial vibration damping spring 7 are coaxially sleeved on the outer wall of the central tube 8. The ends of the two springs respectively abut against the bottom of the upper connector 1 and the top of the outer shell intermediate connector 2, forming an axial graded vibration damping system. A bearing end cap 10, a positioning screw 11, a fixing ring 12, a radial vibration damping spring 13, a radial spring plunger 14, a vibration damping sleeve 15, a bearing 16, and a locking sleeve 18 are integrated and assembled on the main frame of the system to form a radial multi-stage vibration damping system. The radial vibration damping system is nested as a whole on the outer wall of the central tube 8.
[0032] Specifically, the radial damping spring 13 and the radial spring plunger 14 are arranged in a circumferentially equidistant array with the central tube 8 as the axis. The end of the radial spring plunger 14 elastically abuts against the inner wall of the damping sleeve 15 to buffer lateral impact loads.
[0033] Specifically, the positioning screw 11 passes through the bearing end cover 10 and is threadedly locked to the retaining ring 12. The retaining ring 12 is pressed into the inner wall of the locking cylinder 18 through an interference fit, forming a rigid support and positioning function for the radial system. The bearing 16 is an angular contact ball bearing, with its inner ring having an interference fit with the central tube 8 and its outer ring having a clearance fit with the locking cylinder 18, ensuring axial positioning and radial floating freedom.
[0034] Specifically, the mating surfaces of the radial vibration damping outer end housing 9 and the intermediate connecting piece 2 of the outer housing are connected by trapezoidal threads to ensure the sealing performance and fatigue resistance of the housing connection.
[0035] Specifically, both the upper connector 1 and the central tube 8 are provided with API threads at their ends for quick adaptation and installation with the gas well injection and production tubing.
[0036] The radial damping spring 13 and the radial spring plunger 14 are arranged in a circumferentially equidistant array with the central tube 8 as the axis, and the end of the radial spring plunger 14 elastically abuts against the inner wall of the damping sleeve 15.
[0037] The positioning screw 11 passes through the bearing end cover 10 and is threadedly locked to the retaining ring 12. The retaining ring 12 is pressed into the inner wall of the locking cylinder 18 by an interference fit. The bearing 16 is an angular contact ball bearing, with its inner ring having an interference fit with the center tube 8 and its outer ring having a clearance fit with the locking cylinder 18.
[0038] The mating surfaces of the radial vibration damping outer end housing 9 and the intermediate connecting part 2 of the outer housing are connected by a trapezoidal thread with a thread profile angle of 30° and a pitch of 3mm. The main purpose of selecting a trapezoidal thread with a 30° thread profile angle and a 3mm pitch is to optimize the reliability, durability and on-site assembly efficiency of the connection while ensuring the connection strength.
[0039] Trapezoidal threads with a 30° tooth angle have a thicker root and a larger load-bearing cross section than common triangular threads. They can withstand greater axial loads and impacts, are less prone to shear failure, and are very suitable for high-load environments such as downhole tools.
[0040] Trapezoidal threads offer superior frictional self-locking performance compared to many other threads. Their larger contact surface and suitable thread angle make them less prone to loosening under vibration conditions. The larger 3mm pitch allows for faster tightening or loosening in the field, improving work efficiency and reducing the risk of damage from impacts.
[0041] Both the upper connector 1 and the center tube 8 are provided with API standard threads, with a thread specification of NC50 and a taper of 1:16.
[0042] The axial vibration damping system absorbs vertical vibration energy during production in stages through the stiffness gradient design of the upper axial damping spring 6 and the middle axial damping spring 7. The high-stiffness springs preferentially respond to high-frequency impacts, while the low-stiffness springs suppress low-frequency vibrations, thus achieving multi-frequency vibration isolation. The radial vibration damping system converts lateral impact force into spring compression deformation through the synergistic action of the circumferentially distributed radial damping springs 13 and spring plungers 14. The energy is then dissipated by the damping characteristics of the damping sleeve 15, effectively preventing the radial oscillation of the injection and production tubing within the sleeve.
[0043] The threaded locking structure of the positioning screw 11 and the fixing ring 12, combined with the interference fit of the locking cylinder 18, ensures the structural stability of the radial system under long-term alternating loads; the differentiated fit design of the inner and outer rings of the bearing 16 takes into account both the axial rigid support of the central tube 8 and the radial dynamic adjustment capability, reducing friction loss and extending service life.
[0044] The composite vibration damping short section structure consists of an upper connector 1, an outer shell intermediate connector 2, and a radial vibration damping outer end shell 9, which are sequentially screwed together by trapezoidal threads to form a sealed and torsional main frame. The central tube 8 runs through the interior of the main frame. The upper axial vibration damping spring 6 and the middle axial vibration damping spring 7 are coaxially sleeved on the outer wall of the central tube 8. The two adopt a gradient stiffness design of 60N / mm and 40N / mm respectively. The ends are rigidly abutted against the retaining ring 3 and the intermediate connector 2 behind the end of the upper connector 1 to achieve graded absorption of vertical vibration.
[0045] The radial damping springs 13 and spring plungers 14 are evenly distributed in 8 groups around the central tube 8 as the axis. The end of the spring plunger 14 is embedded in the polyurethane damping layer of the inner wall of the damping sleeve 15, and the lateral deformation is ≤2mm.
[0046] The positioning screw 11 is an M12 high-strength internal hexagon screw, which passes through the bearing end cover 10 and locks with the threaded hole of the retaining ring 12. The preload torque is 80 N·m. The outer diameter of the retaining ring 12 and the inner wall of the locking cylinder 18 have an interference fit of 0.05-0.08 mm.
[0047] The trapezoidal threaded connection surface between the radial vibration damping outer end housing 9 and the intermediate connecting piece 2 is coated with a molybdenum disulfide lubricating coating, and the thread engagement length is ≥30mm.
[0048] The sealing structure 4 adopts an O-ring seal. The O-ring seal 17 is placed between the upper connector 1 and the retaining ring 5 on the sealing ring 4 and between the lower end cover 10 and the locking cylinder 18.
[0049] The API threads at the ends of the upper connector 1 and the central tube 8 conform to the ISO 10422 standard, and the thread sealing class is PSL3.
[0050] Working principle of the invention: Combined with appendix Figure 1 The working principle of this invention is a precise floating vibration damping mechanism with inner and outer cylinders. Its core component is a central tube 8 that runs the entire length of the tube. This tube serves as both a fluid channel and a load transfer mechanism, housed within an external frame rigidly connected by an upper connector 1, an outer shell intermediate connector 2, and a radially damping outer shell 9. When dealing with axial vertical vibration, the vertical movement of the central tube 8 is buffered by two sets of upper axial damping springs 6 and middle axial damping springs 7 with different stiffnesses. The retaining ring 5 provides a stable supporting reaction surface for the springs, achieving efficient, graded absorption of vibrations at different frequencies. When dealing with radial horizontal impact, the lateral swing of the central tube 8 drives the damping sleeve 15, which in turn compresses the circumferentially arrayed radial spring plungers 14 and radial damping springs 13. This process not only achieves the first stage of buffering through spring compression but also utilizes the damping layer on the damping sleeve 15 to convert vibration energy into heat dissipation, achieving the second stage of damping energy absorption. The dynamic support and rotation of the entire radial system are achieved by bearing 16, whose outer ring is firmly locked by a precision sleeve structure consisting of locking sleeve 18, retaining ring 12, bearing end cap 10, and positioning screw 11, ensuring stability under extreme operating conditions. Finally, sealing structure 4 and O-ring 17 provide reliable sealing at critical locations, preventing external fluid intrusion and ensuring the normal operation of the internal mechanism.
Claims
1. A vibration-damping short section for gas well injection and production tubing, characterized in that, The system includes an upper connector (1) that is axially connected and fixed by a trapezoidal thread, an outer shell intermediate connector (2) and a radially damping outer shell (9) to form the main frame of the system; a central tube (8) runs through the inside of the main frame of the system, and an upper axial damping spring (6) and a middle axial damping spring (7) are coaxially sleeved on the outer wall of the central tube (8), and the ends of the two abut against the retaining ring (5) at the bottom of the upper connector (1) and the top of the outer shell intermediate connector (2) respectively, together forming an axial graded damping system; The retaining ring (5) is located at the lower end of the upper connector (1); The radial damping outer end housing (9) is used to install and fix the radial damping system.
2. The vibration-damping short section for gas well injection and production tubing according to claim 1, characterized in that, The upper connector (1) is a thick-walled tubular component with a standard connecting thread on the top. Its upper end is a standard API threaded connector, which is used to connect with the main body of the injection and production tubing of the gas well. The interior is a hollow channel, and the inner wall of its lower end is machined with an internal thread for screwing with the external thread of the intermediate connector (2) of the outer shell. At the bottom of the hollow channel, a groove is also machined for placing the retaining ring (5) to provide support for the upper axial damping spring (6).
3. The vibration-damping short section for gas well injection and production tubing according to claim 1, characterized in that, The intermediate connecting part (2) of the outer shell is a double-ended threaded tubular connecting part, which is used to connect the upper connector (1) and the radial vibration damping outer shell (9) respectively. The upper outer wall is machined with external threads for screwing into the internal threads of the upper connector (1), and the lower inner wall is machined with internal threads for connecting the radial vibration damping outer shell (9). The top end face of the intermediate connecting part (2) of the outer shell is a flat annular surface, which is used as the support surface of the central axial vibration damping spring (7).
4. The vibration-damping short section for gas well injection and production tubing according to claim 1, characterized in that, The radial vibration damping outer end housing (9) is in the shape of a thick-walled tube. Its upper outer wall is machined with external threads for internal thread connection with the intermediate connecting part (2) of the outer housing. The diameter of its internal cavity is much larger than the two parts above, and the inner wall is machined with precision steps and positioning surfaces.
5. A vibration-damping short section for gas well injection and production tubing according to claim 1, characterized in that, The central tube (8) is a stepped hollow shaft that runs through the main frame of the system. The upper end is provided with an API standard thread for connecting to the injection and production tubing. The tube body is provided with multiple steps of different outer diameters, which are used to install and position the upper axial damping spring (6), the middle axial damping spring (7), the damping sleeve (15), and the inner ring of the bearing (16). The shoulders of the steps provide axial support for the relevant components.
6. A vibration-damping short section for gas well injection and production tubing according to claim 5, characterized in that, The upper axial damping spring (6) is fitted on the step with a smaller outer diameter on the upper section of the central tube (8). Its axial position is limited between the retaining ring (5) at the bottom of the upper connector (1) and one of the upward steps of the central tube (8). The middle axial damping spring (7) is fitted on the step with a larger outer diameter in the middle section of the central tube (8). Its axial position is limited between the top of the intermediate connector (2) of the outer housing and another upward step of the central tube (8). The retaining ring (5) is installed at the bottom inside the upper connector (1).
7. A vibration-damping short section for gas well injection and production tubing according to claim 1, characterized in that, The radial vibration damping system includes a locking cylinder (18), a bearing (16), and a fixing ring (12). The locking cylinder (18), bearing (16), and fixing ring (12) are integrated and assembled inside the radial vibration damping outer end housing (9). The locking cylinder (18) is fixedly installed inside the outer end housing (9). The fixing ring (12) is pressed into the inner wall of the locking cylinder (18) by an interference fit. A bearing end cap (10) is provided at the open end of the locking cylinder (18). The bearing end cap (10) is locked by a positioning screw (11) through itself and the threaded hole on the fixing ring (12), so that the fixing ring (12) and the locking cylinder (18) are firmly assembled together.
8. A vibration-damping short section for gas well injection and production tubing according to claim 7, characterized in that, The outer ring of the bearing (16) is clearance-fitted with the inner wall of the locking cylinder (18), while its inner ring is interference-fitted with the central tube (8). The damping sleeve (15) is fitted onto the outer wall of the central tube (8). Multiple sets of radial damping springs (13) and radial spring plungers (14) are arranged in a circumferential array and placed between the locking cylinder (18) and the damping sleeve (15). One end of the spring plunger (14) is elastically pressed against the outer wall of the damping sleeve (15) under the elastic force of the spring (13), thereby achieving radial buffering and damping of the central tube (8). The positioning screw (11) passes through the bearing end cover (10) and is threadedly locked with the fixing ring (12). The fixing ring (12) is pressed into the inner wall of the locking cylinder (18) by interference fit, forming a rigid support and positioning function of the radial system. The bearing (16) adopts an angular contact ball bearing, with its inner ring interference fit with the center tube (8) and its outer ring clearance fit with the locking cylinder (18), ensuring axial positioning and radial floating freedom.
9. A vibration-damping short section for gas well injection and production tubing according to claim 1, characterized in that, The mating surfaces of the radial vibration damping outer end shell (9) and the intermediate connecting piece (2) of the outer shell are connected by trapezoidal threads; The ends of the upper connector (1) and the central tube (8) are both provided with API threads for quick adaptation and installation with the gas well injection and production tubing. The mating surfaces of the radial vibration damping outer end housing (9) and the intermediate connecting part (2) of the outer housing are connected by trapezoidal thread with a thread profile angle of 30° and a pitch of 3mm. A sealing ring (4) is provided between the upper connector (1) and the retaining ring (5), and an O-ring (17) is provided between the lower end cover (10) and the locking cylinder (18).
10. A method for using a vibration-damping short section for gas well injection and production tubing as described in any one of claims 1-9, characterized in that, Including the following methods: When dealing with axial vertical vibration, the up-and-down movement of the central tube (8) is buffered by two sets of upper axial damping springs (6) and middle axial damping springs (7) with different stiffness. The retaining ring (5) provides a stable support reaction surface for the spring, realizing graded and efficient absorption of vibrations of different frequencies. When dealing with radial horizontal impact, the lateral swing of the central tube (8) will drive the damping sleeve (15), which in turn squeezes the radial spring plunger (14) and radial damping spring (13) arranged in a circumferential array. This process not only achieves the first-stage buffering through the compression of the spring, but also utilizes the damping layer on the damping sleeve (15) to convert vibration energy into heat energy dissipation, thus achieving the second-stage damping energy absorption.