A high sealing bidirectional jar

Abstract

The application relates to a high-sealing bidirectional jar, which comprises a shell, a mandrel slidingly arranged in the shell, the shell comprises a driving outer cylinder, a hydraulic cylinder, an upper stop cylinder, a balance oil cylinder, a lower stop cylinder and a lower joint which are sequentially connected, the upper stop cylinder is slidingly connected with an upper mandrel, the balance oil cylinder is slidingly connected with a middle mandrel, and the lower stop cylinder is slidingly connected with a lower mandrel; a top end of the upper stop cylinder, a bottom end of the lower piston and the outer wall of the balance piston are all embedded with sealing assemblies, the sealing assembly comprises a main sealing ring, a mud scraping ring and a wear-resistant blocking ring, the mud scraping ring is tightly attached to the two ends of the main sealing ring, the wear-resistant blocking ring is tightly attached to the side of the mud scraping ring which is far away from each other, and the main sealing ring is an elastic sealing member. The application has the effect of improving the reliability of the jar.

Description

Technical Field

[0001] This invention relates to the field of shock absorbers, and more particularly to a highly sealed bidirectional shock absorber. Background Technology

[0002] In drilling operations, stuck pipe accidents frequently occur due to complex geological structures, inappropriate technical measures, and various reasons such as mud, tubing, and wellbore issues. Stuck pipe has a significant impact on drilling operations and poses serious risks. Improper handling not only wastes time and reduces drilling footage but can also worsen the accident, even leading to the abandonment of the oil and gas well. A tremor is one of the effective tools for resolving stuck pipe and preventing more serious accidents. When the drill string becomes stuck, a tremor is used to apply strong upward or downward impact to the stuck point, loosening the blockage and thus resolving the stuck pipe.

[0003] The bidirectional vibrator includes an upper stop cylinder, a balance cylinder, and a lower stop cylinder. An upper mandrel is slidably connected inside the upper stop cylinder, an intermediate mandrel is slidably connected inside the balance cylinder, and a lower mandrel is slidably connected inside the lower stop cylinder. The upper, intermediate, and lower mandrels are sequentially threaded together. An upper piston is coaxially connected to the outer circumferential wall of the upper mandrel, and a lower piston is coaxially connected to the outer circumferential wall of the lower mandrel. There is a gap between the upper piston and the upper stop cylinder for fluid flow, and a gap between the lower piston and the lower stop cylinder for fluid flow. Both the upper and lower stop cylinders are equipped with high-pressure zones, which are formed by the inner wall constriction. Oil needles are inserted on both the upper and lower pistons, through which liquid passes. When the upper and lower pistons pass through the corresponding high-pressure zones, the liquid can only flow through the oil needles. A balance piston is coaxially connected to the outer peripheral wall of the intermediate spindle. Both the inner and outer peripheral walls of the balance piston are equipped with seals. The seals of the balance piston are always interference-fitted with the outer peripheral wall of the intermediate spindle and the inner peripheral wall of the balance cylinder to separate the upper and lower oil chambers.

[0004] When the shock absorber is needed for an upward impact operation, sufficient tension is applied to the upper mandrel using a tool. The upper mandrel drives the upper piston to move. When the upper piston reaches the high-pressure zone, its movement is obstructed. At this point, the shock absorber stores energy, and liquid flows out through the needle port on the upper piston under pressure. During this process, the upper piston moves slowly under tension until it reaches the high-pressure zone. Suddenly, the resistance to the upper piston's movement decreases sharply, the upper mandrel is released, and the shock absorber generates an impact. Simultaneously, the lower piston of the lower mandrel also passes through the high-pressure zone and is released. The downward impact process follows the same principle as the upward impact.

[0005] Currently, the commonly used high-sealing bidirectional shock absorbers use only rubber rings as seals. Under the high temperature and repeated wear at the bottom of the well, the balance cylinder is prone to sealing failure. Oil leakage between the upper and lower oil chambers leads to an imbalance of oil pressure in the upper and lower oil chambers, resulting in insufficient energy storage. Consequently, the shock force is insufficient or even the shock effect is lost. Therefore, the reliability of the shock absorber needs to be improved. Summary of the Invention

[0006] To address the aforementioned technical problems, this application provides a highly sealing bidirectional shock absorber.

[0007] The high-sealing bidirectional shock absorber provided in this application adopts the following technical solution:

[0008] A high-sealing bidirectional shock absorber includes a housing and a spindle slidably disposed within the housing. The housing includes a drive outer cylinder, a hydraulic cylinder, an upper stop cylinder, a balance cylinder, a lower stop cylinder, and a lower connector connected in sequence. An upper spindle is slidably connected within the upper stop cylinder, an intermediate spindle is slidably connected within the balance cylinder, and a lower spindle is slidably connected within the lower stop cylinder. The upper spindle, intermediate spindle, and lower spindle are threadedly connected in sequence.

[0009] An upper piston is coaxially connected to the outer peripheral wall of the upper mandrel, an upper high-pressure zone is provided inside the upper stop cylinder, a lower piston is coaxially connected to the outer peripheral wall of the lower mandrel, a lower high-pressure zone is provided inside the lower stop cylinder, and a balance piston is coaxially connected to the inner peripheral wall of the balance cylinder.

[0010] Sealing components are embedded in the inner peripheral wall of the upper stop cylinder at the end away from the intermediate spindle, the inner peripheral wall of the lower stop cylinder at the end away from the intermediate spindle, and the inner and outer peripheral walls of the balance piston.

[0011] The sealing assembly includes a main sealing ring, a mud scraper ring, and a wear-resistant blocking ring. The mud scraper ring is tightly attached to both ends of the main sealing ring, and the wear-resistant blocking ring is tightly attached to the side of the mud scraper ring that is far away from each other. The main sealing ring is an elastic sealing component.

[0012] The main sealing ring of the upper stop cylinder is always in interference fit with the outer peripheral wall of the upper mandrel, the main sealing ring of the lower stop cylinder is always in interference fit with the outer peripheral wall of the lower mandrel, the main sealing ring of the inner peripheral wall of the balance piston is always in interference fit with the outer peripheral wall of the intermediate mandrel, and the main sealing ring of the balance piston is always in interference fit with the inner peripheral wall of the balance cylinder.

[0013] Preferably, both the inner peripheral walls of the upper stop cylinder and the lower stop cylinder are provided with limiting ring grooves for the sealing assembly to be embedded. The cross-section of the limiting ring groove is trapezoidal. In the limiting ring groove, the sealing assembly is trapezoidal in shape and completely located within the limiting ring groove. The sealing ring is folded so that the cross-section of the sealing ring is U-shaped, the cross-section of the mud scraper ring is rectangular, and the cross-section of the wear-resistant blocking ring is trapezoidal. The inclined surface of the wear-resistant blocking ring is in close contact with the inclined surface of the limiting ring groove.

[0014] Preferably, the inner and outer peripheral walls of the balance piston are provided with balance ring grooves for the sealing assembly to be embedded. The balance ring grooves are trapezoidal. The sealing assembly is provided with fixing rings at both ends. In the balance ring groove, the sealing assembly is T-shaped as a whole, and the fixing rings are L-shaped. The horizontal part of the fixing rings is engaged in the groove of the sealing assembly. The vertical parts of the fixing rings are inclined and closely attached to the inclined surface of the balance ring groove. The two fixing rings apply pressure to the sealing assembly, causing the top surface of the sealing assembly to bulge outward.

[0015] Preferably, the mud scraper ring is made of glass-filled Teflon, and the wear-resistant retaining ring is made of copper.

[0016] By adopting the above technical solution, the mud scraper ring not only serves as a gasket between the main sealing ring and the wear-resistant blocking ring, but also polishes and adaptively adjusts the squeezing pressure on the main sealing ring when the chromium or alloy shaft reciprocates under pressure. When pressure is applied to the main sealing ring, the wear-resistant blocking ring is forced to move downwards along the inclined tapered slope of the inner wall of the tank to adapt to the situation, preventing excessive squeezing between the mud scraper ring and the main sealing ring.

[0017] By using a composite sealing assembly, the high-temperature resistance and wear resistance of the shock absorber's sealing components are greatly improved. This prevents sealing failures in the upper stop cylinder, lower stop cylinder, and balance cylinder, reducing the possibility of leakage from the upper and lower stop cylinders and oil leakage from the upper and lower oil chambers. It ensures oil pressure balance between the upper and lower oil chambers and the overall sealing performance of the shock absorber, guaranteeing the energy storage effect and the shock absorber's impact force, thereby improving the shock absorber's reliability.

[0018] Preferably, the upper piston includes an upper limit ring one, an upper stop ring, and an upper limit ring two. The upper limit ring one and the upper limit ring two are fixedly located on the upper spindle. The upper stop ring is slidably connected between the upper limit ring one and the upper limit ring two. An oil hole is opened on the upper stop ring, and an oil needle is inserted into the oil hole. The outer peripheral wall of the oil needle is provided with external threads.

[0019] The lower piston includes a lower limit ring one, a lower stop ring, and a lower limit ring two. The lower limit ring one and the lower limit ring two are fixedly located on the lower mandrel. The lower stop ring is slidably connected between the lower limit ring one and the lower limit ring two. The lower stop ring has a lower oil hole, and a lower oil needle is inserted into the lower oil hole. The outer peripheral wall of the lower oil needle is provided with external threads.

[0020] Preferably, the upper limit ring one is integrally formed on the upper mandrel, the upper limit ring two is threadedly connected to the upper mandrel, the length of the upper stop ring is A1, the length of the upper oil needle is A2, the distance between the upper limit ring one and the upper limit ring two is A3, and A2-A1≥A3-A2;

[0021] The lower limit ring one is integrally formed on the lower mandrel, the lower limit ring two is threadedly connected to the lower mandrel, the length of the lower stop ring is B1, the length of the lower oil needle is B2, the distance between the lower limit ring one and the lower limit ring two is B3, and B2-B1≥B3-B2.

[0022] By adopting the above technical solution, the distance between the upper limit ring and the upper limit ring is adjusted by rotating the upper limit ring two, and the distance between the lower limit ring and the lower limit ring is adjusted by rotating the lower limit ring two. This adjusts the movable space of the upper stop ring and the movable space of the lower stop ring, thereby adjusting the flow area of ​​the liquid flowing through the high-pressure zone corresponding to the shock absorber, adjusting the shock absorber's shock force, and enabling the shock absorber to meet the usage requirements of different well bottom temperatures and different hydraulic oils.

[0023] Preferably, the upper high-pressure zone of the upper stop cylinder and the lower high-pressure zone of the lower stop cylinder are both formed by the inner wall constriction.

[0024] Preferably, the upper stop cylinder is connected to the balance cylinder via an upper connecting joint, and the upper connecting joint is provided with an oil injection hole that communicates with the interior of the upper stop cylinder and the interior of the balance cylinder.

[0025] By adopting the above technical solution, it is easy to disassemble and assemble the upper stop cylinder and the balance cylinder.

[0026] Preferably, the lower stop cylinder is connected to the balance cylinder via a lower connecting joint, and the lower connecting joint has an oil injection hole that communicates with the interior of the lower stop cylinder and the interior of the balance cylinder.

[0027] By adopting the above technical solution, it is easy to disassemble and assemble the lower stop cylinder and the balance cylinder.

[0028] Preferably, the outer diameter of the lower mandrel is larger than the outer diameter of the upper mandrel.

[0029] By adopting the above technical solution, the outer diameter of the lower mandrel is set to be slightly larger than that of the upper mandrel, which conforms to the actual engineering situation and prevents the mandrel of the vibrator from breaking during operation.

[0030] In summary, this application includes at least one of the following beneficial technical effects:

[0031] 1. By using a composite sealing component, the high temperature resistance and wear resistance of the shock absorber's sealing components are greatly improved, avoiding sealing failures in the upper stop cylinder, lower stop cylinder, and balance cylinder. This reduces the possibility of leakage in the upper stop cylinder, lower stop cylinder, and oil leakage in the upper and lower oil chambers, ensuring oil pressure balance between the upper and lower oil chambers and the overall sealing performance of the shock absorber. It also ensures the energy storage effect and the shock absorber's impact force, thereby improving the shock absorber's reliability.

[0032] 2. By rotating the upper limit ring two to adjust the distance between the upper limit ring two and the upper limit ring one, and by rotating the lower limit ring two to adjust the distance between the lower limit ring two and the lower limit ring one, the movable space of the upper stop ring and the movable space of the lower stop ring are adjusted, thereby adjusting the flow area of ​​the liquid flowing through the high-pressure zone corresponding to the shock absorber, adjusting the shock absorber's shock force, and enabling the shock absorber to meet the usage requirements of different well bottom temperatures and different hydraulic oils. Attached Figure Description

[0033] Figure 1 This is a cross-sectional structural diagram of the drive outer cylinder, hydraulic cylinder, and upper stop cylinder used in the embodiments of this application.

[0034] Figure 2 This is a cross-sectional structural diagram of the upper stop cylinder and the balance cylinder in the embodiments of this application.

[0035] Figure 3 This is a cross-sectional structural diagram illustrating the balance cylinder, lower stop cylinder, and lower connector in the embodiments of this application.

[0036] Figure 4 This is a cross-sectional structural diagram of the sealing assembly located in the limiting ring groove in an embodiment of this application.

[0037] Figure 5 This is a cross-sectional structural diagram illustrating the relationship between the sealing assembly located within the balance ring groove and the fixing ring in an embodiment of this application.

[0038] Figure 6 This is a cross-sectional structural diagram of the upper piston of the upper stop cylinder in an embodiment of this application.

[0039] Figure 7 This is an exploded structural diagram used in the embodiments of this application to illustrate the upper stop ring and the oil needle.

[0040] Figure 8 This is a cross-sectional structural diagram of the upper piston of the lower stop cylinder in an embodiment of this application.

[0041] Explanation of reference numerals in the attached drawings: 10. Drive outer cylinder; 11. Hydraulic cylinder; 111. Striking joint; 12. Upper stop cylinder; 121. Upper high-pressure zone; 13. Balance cylinder; 14. Lower stop cylinder; 141. Lower high-pressure zone; 15. Lower joint; 20. Splined shaft; 21. Striker; 22. Upper spindle; 221. Upper piston; 2211. Limiting ring one; 2212. Upper stop ring; 2213. Upper limit ring two; 2214. 23. Upper oil needle; 24. Middle mandrel; 25. Balance piston; 26. Lower mandrel; 27. Lower piston; 28. Lower limit ring 1; 29. ​​Lower stop ring; 20. Lower limit ring 2; 20. Lower oil needle; 21. Sealing assembly; 22. Main sealing ring; 33. Mud scraper ring; 44. Wear-resistant blocking ring; 55. Limiting ring groove; 66. Balance ring groove; 77. Fixing ring; 88. Upper connecting joint; 99. Lower connecting joint. Detailed Implementation

[0042] The following is in conjunction with the appendix Figure 1-8 This application will be described in further detail.

[0043] This application discloses a highly sealing bidirectional shock absorber.

[0044] Reference Figure 1-8 The high-sealing bidirectional vibrator includes a housing 1 and a mandrel slidably disposed within the housing 1. The housing 1 includes a drive outer cylinder 10, a hydraulic cylinder 11, an upper stop cylinder 12, a balance cylinder 13, a lower stop cylinder 14, and a lower connector 15 connected in sequence. A splined shaft 20 is slidably connected inside the drive outer cylinder 10, and an impactor 21 is slidably connected inside the hydraulic cylinder 11. The lower end of the drive outer cylinder 10 is connected to the hydraulic cylinder 11 via an impact connector 111, which is threadedly connected to the inner wall of the hydraulic cylinder 11. The lower connector 15 is connected to the lower drill bit. An upper mandrel 22 is slidably connected inside the upper stop cylinder 12, an intermediate mandrel 23 is slidably connected inside the balance cylinder 13, and a lower mandrel 24 is slidably connected inside the lower stop cylinder 14. The splined shaft 20, impactor 21, upper mandrel 22, intermediate mandrel 23, and lower mandrel 24 are threadedly connected in sequence. The impactor 21 can slide to impact the impact connector 111.

[0045] An upper piston 221 is coaxially connected to the outer peripheral wall of the upper mandrel 22. An upper high-pressure zone 121 is provided inside the upper stop cylinder 12. A lower piston 241 is coaxially connected to the outer peripheral wall of the lower mandrel 24. A lower high-pressure zone 141 is provided inside the lower stop cylinder 14. The upper high-pressure zone 121 of the upper stop cylinder 12 and the lower high-pressure zone 141 of the lower stop cylinder 14 are both formed by the inner wall constriction.

[0046] A balance piston 231 is coaxially connected to the outer peripheral wall of the intermediate spindle 23.

[0047] Sealing components 3 are embedded in the inner peripheral wall of the upper stop cylinder 12 away from the middle spindle 23, the inner peripheral wall of the lower stop cylinder 14 away from the middle spindle 23, and the inner and outer peripheral walls of the balance piston 231.

[0048] The sealing assembly 3 includes a main sealing ring 31, a mud scraper ring 32, and a wear-resistant blocking ring 33. The mud scraper ring 32 is tightly attached to both ends of the main sealing ring 31, and the wear-resistant blocking ring 33 is tightly attached to the side of the mud scraper ring 32 that is far away from each other. The main sealing ring 31 is an elastic sealing component.

[0049] The inner peripheral walls of the upper stop cylinder 12 and the lower stop cylinder 14 are both provided with limiting ring grooves 4 for the sealing assembly 3 to be embedded. The cross-section of the limiting ring groove 4 is trapezoidal. In the limiting ring groove 4, the sealing assembly 3 is trapezoidal in shape and is completely located in the limiting ring groove 4. The sealing ring is folded so that the cross-section of the sealing ring is U-shaped, the cross-section of the mud scraper ring 32 is rectangular, and the cross-section of the wear-resistant blocking ring 33 is trapezoidal. The inclined surface of the wear-resistant blocking ring 33 is in close contact with the inclined surface of the limiting ring groove 4.

[0050] The main sealing ring 31 of the upper stop cylinder 12 is always in interference fit with the outer peripheral wall of the upper spindle 22, the main sealing ring 31 of the lower stop cylinder 14 is always in interference fit with the outer peripheral wall of the lower spindle 24, the main sealing ring 31 of the inner peripheral wall of the balance piston 231 is always in interference fit with the outer peripheral wall of the intermediate spindle 23, and the main sealing ring 31 of the outer peripheral wall of the balance piston 231 is always in interference fit with the inner peripheral wall of the balance cylinder 13.

[0051] The inner and outer peripheral walls of the balance piston 231 are provided with balance ring grooves 5 for the sealing assembly 3 to be embedded. The balance ring grooves 5 are trapezoidal. The sealing assembly 3 is provided with fixing rings 51 at both ends. In the balance ring grooves 5, the sealing assembly 3 is T-shaped as a whole, and the fixing rings 51 are L-shaped. The horizontal part of the fixing rings 51 is stuck in the groove of the sealing assembly 3. The vertical part of the fixing rings 51 is inclined and closely attached to the inclined surface of the balance ring groove 5. The two fixing rings 51 apply pressure to the sealing assembly 3, causing the top surface of the sealing assembly 3 to bulge outward.

[0052] The mud scraper ring 32 is made of glass-filled Teflon, and the wear-resistant blocking ring 33 is made of copper.

[0053] The mud scraper ring 32 not only serves as a gasket between the main sealing ring 31 and the wear-resistant retaining ring 33, but also polishes and adaptively adjusts the squeezing pressure on the main sealing ring 31 when the chromium or alloy shaft reciprocates under pressure. When pressure is applied to the main sealing ring 31, the wear-resistant retaining ring 33 is forced to move downwards along the inclined tapered surface of the inner wall of the tank to prevent excessive squeezing of the mud scraper ring 32 and the main sealing ring 31.

[0054] By setting up the composite sealing component 3, the high temperature resistance and wear resistance of the shock absorber sealing component 3 are greatly improved, the sealing failure of the balance cylinder 13 is avoided, the possibility of oil leakage between the upper and lower oil chambers is reduced, the oil pressure balance between the upper and lower oil chambers is guaranteed, the energy storage effect is guaranteed, the shock force of the shock absorber is guaranteed, and thus the reliability of the shock absorber is improved.

[0055] The upper piston 221 includes an upper limit ring 1 2211, an upper stop ring 2212, and an upper limit ring 2213. The upper limit ring 1 2211 and the upper limit ring 2213 are fixedly located on the upper spindle 22. The upper stop ring 2212 is slidably connected between the upper limit ring 1 2211 and the upper limit ring 2213. An oil hole is provided on the upper stop ring 2212, and an oil needle 2214 is inserted into the oil hole. The outer peripheral wall of the oil needle 2214 is provided with external threads.

[0056] The lower piston 241 includes a lower limit ring 1 24112211, a lower stop ring 2412, and a lower limit ring 2413. The lower limit ring 1 24112211 and the lower limit ring 2413 are fixedly located on the lower spindle 24. The lower stop ring 2412 is slidably connected between the lower limit ring 1 24112211 and the lower limit ring 2413. The lower stop ring 2412 has a lower oil hole, and a lower oil needle 2414 is inserted into the lower oil hole. The outer peripheral wall of the lower oil needle 2414 is provided with external threads.

[0057] Upper limit ring 1 2211 is integrally formed on upper mandrel 22, upper limit ring 2213 is threadedly connected to upper mandrel 22, the length of upper stop ring 2212 is A1, the length of upper oil needle 2214 is A2, the distance between upper limit ring 1 2211 and upper limit ring 2213 is A3, and A2-A1≥A3-A2;

[0058] The lower limit ring 24112211 is integrally formed on the lower mandrel 24. The lower limit ring 2413 is threadedly connected to the lower mandrel 24. The length of the lower stop ring 2412 is B1. The length of the lower oil needle 2414 is B2. The distance between the lower limit ring 24112211 and the lower limit ring 2413 is B3. B2-B1≥B3-B2.

[0059] By rotating the upper limit ring 2213 to adjust the distance between the upper limit ring 2213 and the upper limit ring 1 2211, and by rotating the lower limit ring 2413 to adjust the distance between the lower limit ring 2413 and the lower limit ring 1 2411, the movable space of the upper stop ring 2212 and the movable space of the lower stop ring 2412 are adjusted. This, in turn, adjusts the flow area of ​​the liquid flowing through the high-pressure zone corresponding to the shock absorber, adjusts the shock absorber's shock force, and enables the shock absorber to meet the usage requirements of different bottom hole temperatures and different hydraulic oils.

[0060] The upper stop cylinder 12 is connected to the balance cylinder 13 via the upper connecting joint 6. The upper connecting joint 6 has an oil filling hole that communicates with the interior of the upper stop cylinder 12 and the balance cylinder 13, facilitating the disassembly and assembly of the upper stop cylinder 12 and the balance cylinder 13. When no hydraulic oil is injected, a pressure plug is interference-fitted into the oil filling hole.

[0061] The lower stop cylinder 14 is connected to the balance cylinder 13 via the lower connecting joint 7. The lower connecting joint 7 has an oil filling hole 2 that communicates with the interior of the lower stop cylinder 14 and the balance cylinder 13, facilitating the disassembly and assembly of the lower stop cylinder 14 and the balance cylinder 13. When no hydraulic oil is injected, a pressure plug 2 is interference-fitted inside the oil filling hole 2.

[0062] The outer diameter of the lower spindle 24 is larger than that of the upper spindle 22, which fits the actual engineering requirements and prevents the spindle of the vibrator from breaking during operation.

[0063] The implementation principle of a high-sealing bidirectional shock absorber according to an embodiment of this application is as follows:

[0064] When the shocker needs to perform an impact operation, sufficient tension is applied to the upper mandrel 22 using a tool. The upper mandrel 22 drives the upper piston 221 to move. When the upper piston 221 moves to the high-pressure zone, its movement is obstructed. At this time, the shocker stores energy, and the liquid slowly flows out through the oil needle of the upper piston 221 under pressure. During this process, the upper piston 221 moves slowly under the action of tension until it reaches the high-pressure zone. The resistance to the movement of the upper piston 221 suddenly decreases sharply, the upper mandrel 22 is released, and the shocker produces an impact. At the same time, the lower piston 241 of the lower mandrel 24 is also released after passing through the high-pressure zone.

[0065] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A high-sealing bidirectional shock absorber, characterized in that: The device includes a housing and a mandrel slidably disposed within the housing. The housing includes a drive outer cylinder (10), a hydraulic cylinder (11), an upper stop cylinder (12), a balance cylinder (13), a lower stop cylinder (14), and a lower connector (15) connected in sequence. An upper mandrel (22) is slidably connected inside the upper stop cylinder (12), an intermediate mandrel (23) is slidably connected inside the balance cylinder (13), and a lower mandrel (24) is slidably connected inside the lower stop cylinder (14). The upper mandrel (22), the intermediate mandrel (23), and the lower mandrel (24) are connected by threads in sequence. An upper piston (221) is coaxially connected to the outer peripheral wall of the upper mandrel (22), an upper high-pressure zone (121) is provided inside the upper stop cylinder (12), a lower piston (241) is coaxially connected to the outer peripheral wall of the lower mandrel (24), a lower high-pressure zone (141) is provided inside the lower stop cylinder (14), and a balance piston (231) is coaxially connected to the inner peripheral wall of the balance cylinder (13). Sealing components (3) are embedded in the inner peripheral wall of the upper stop cylinder (12) away from the middle spindle (23), the inner peripheral wall of the lower stop cylinder (14) away from the middle spindle (23), and the inner and outer peripheral walls of the balance piston (231). The sealing assembly (3) includes a main sealing ring (31), a mud scraper ring (32), and a wear-resistant blocking ring (33). The mud scraper ring (32) is in close contact with both ends of the main sealing ring (31), and the wear-resistant blocking ring (33) is in close contact with the side of the mud scraper ring (32) that is far away from each other. The main sealing ring (31) is an elastic sealing component. The main sealing ring (31) of the upper stop cylinder (12) is always in interference fit with the outer peripheral wall of the upper spindle (22), the main sealing ring (31) of the lower stop cylinder (14) is always in interference fit with the outer peripheral wall of the lower spindle (24), the main sealing ring (31) of the inner peripheral wall of the balance piston (231) is always in interference fit with the outer peripheral wall of the middle spindle (23), and the main sealing ring (31) of the balance piston (231) is always in interference fit with the inner peripheral wall of the balance cylinder (13). The inner peripheral walls of the upper stop cylinder (12) and the lower stop cylinder (14) are provided with limiting ring grooves (4) for the sealing assembly (3) to be embedded. The cross-section of the limiting ring groove (4) is trapezoidal. In the limiting ring groove (4), the sealing assembly (3) is trapezoidal in shape and is completely located in the limiting ring groove (4). The sealing ring is folded so that the cross-section of the sealing ring is U-shaped. The cross-section of the mud scraper ring (32) is rectangular. The cross-section of the wear-resistant blocking ring (33) is trapezoidal. The inclined surface of the wear-resistant blocking ring (33) is in close contact with the inclined surface of the limiting ring groove (4). The inner and outer peripheral walls of the balance piston (231) are provided with balance ring grooves (5) for the sealing assembly (3) to be embedded. The balance ring grooves (5) are trapezoidal. The sealing assembly (3) is provided with fixing rings (51) at both ends. In the balance ring grooves (5), the sealing assembly (3) is T-shaped as a whole, and the fixing rings (51) are L-shaped. The horizontal part of the fixing rings (51) is stuck in the groove of the sealing assembly (3). The vertical part of the fixing rings (51) is inclined and closely attached to the inclined surface of the balance ring groove (5). The two fixing rings (51) apply pressure to the sealing assembly (3) to make the top surface of the sealing assembly (3) bulge outward.

2. The high-sealing bidirectional shock absorber according to claim 1, characterized in that: The mud scraper ring (32) is made of glass-filled Teflon, and the wear-resistant blocking ring (33) is made of copper.

3. The high-sealing bidirectional shock absorber according to claim 1, characterized in that: The upper piston (221) includes an upper limit ring one (2211), an upper stop ring (2212), and an upper limit ring two (2213). The upper limit ring one (2211) and the upper limit ring two (2213) are fixedly located on the upper spindle (22). The upper stop ring (2212) is slidably connected between the upper limit ring one (2211) and the upper limit ring two (2213). An oil hole is provided on the upper stop ring (2212), and an oil needle (2214) is inserted into the oil hole. The outer peripheral wall of the oil needle (2214) is provided with external threads. The lower piston (241) includes a lower limiting ring one (2411), a lower stop ring (2412), and a lower limiting ring two (2413). The lower limiting ring one (2411) and the lower limiting ring two (2413) are fixedly located on the lower spindle (24). The lower stop ring (2412) is slidably connected between the lower limiting ring one (2411) and the lower limiting ring two (2413). The lower stop ring (2412) has a lower oil hole, and a lower oil needle (2414) is inserted into the lower oil hole. The outer peripheral wall of the lower oil needle (2414) is provided with external threads.

4. The high-sealing bidirectional shock absorber according to claim 3, characterized in that: The upper limit ring one (2211) is integrally formed on the upper mandrel (22), the upper limit ring two (2213) is threadedly connected to the upper mandrel (22), the length of the upper stop ring (2212) is A1, the length of the upper oil needle (2214) is A2, the distance between the upper limit ring one (2211) and the upper limit ring two (2213) is A3, and A2-A1≥A3-A2; The lower limit ring one (2411) is integrally formed on the lower mandrel (24), the lower limit ring two (2413) is threadedly connected to the lower mandrel (24), the length of the lower stop ring (2412) is B1, the length of the lower oil needle (2414) is B2, the distance between the lower limit ring one (2411) and the lower limit ring two (2413) is B3, and B2-B1≥B3-B2.

5. The high-sealing bidirectional shock absorber according to claim 1, characterized in that: The upper high-pressure zone (121) of the upper stop cylinder (12) and the lower high-pressure zone (141) of the lower stop cylinder (14) are both formed by the inner wall constriction.

6. The high-sealing bidirectional shock absorber according to claim 1, characterized in that: The upper stop cylinder (12) is connected to the balance cylinder (13) through the upper connecting joint (6). The upper connecting joint (6) has an oil injection hole that communicates with the inside of the upper stop cylinder (12) and the inside of the balance cylinder (13).

7. The high-sealing bidirectional shock absorber according to claim 1, characterized in that: The lower stop cylinder (14) is connected to the balance cylinder (13) through the lower connecting joint (7). The lower connecting joint (7) has an oil injection hole that communicates with the interior of the lower stop cylinder (14) and the interior of the balance cylinder (13).

8. The high-sealing bidirectional shock absorber according to claim 1, characterized in that: The outer diameter of the lower mandrel (24) is greater than the outer diameter of the upper mandrel (22).

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