Gas spring structure for high temperature high pressure environment

Abstract

The gas spring structure for high temperature and high pressure environment comprises a nitrogen chamber and an oil chamber connected with each other, the nitrogen chamber comprises a nitrogen cavity outer cylinder, one end of the nitrogen cavity outer cylinder is connected with an upper joint outer cylinder, the other end is connected with an oil chamber outer cylinder of the oil chamber, the inner side of the nitrogen cavity outer cylinder is provided with a nitrogen cavity mandrel along the nitrogen cavity outer cylinder in the axial direction, the nitrogen cavity mandrel penetrates through the upper joint outer cylinder, a chamber containing nitrogen is formed between the nitrogen cavity outer cylinder and the nitrogen cavity mandrel, a transmission hole is formed on the nitrogen cavity outer cylinder at the position opposite to the chamber, and the annular space pressure enters the chamber through the transmission hole to realize the movement of the nitrogen cavity mandrel; the inner side of the oil chamber outer cylinder is provided with an oil chamber mandrel along the oil chamber outer cylinder in the axial direction, an oil cavity is formed between the oil chamber outer cylinder and the oil chamber mandrel, the oil cavity is communicated with the nitrogen chamber through an oil passage, and the end of the oil chamber outer cylinder away from the nitrogen cavity outer cylinder is connected with a lower joint. The pre-charged nitrogen pressure of the gas spring structure on the ground is reduced, and the operation safety is improved.

Description

Technical Field

[0001] This invention belongs to the technical field of downhole oil and gas testing equipment, specifically relating to a gas spring structure for use in high-temperature and high-pressure environments. Background Technology

[0002] Oil and natural gas are the lifeblood of the world economy. Oil and natural gas wells are usually made by drilling deep holes in the ground with drilling rigs, and then bringing oil and natural gas from underground to the surface. After drilling is completed, testing equipment is usually placed in the oil and gas well to test the well. The traditional method is to set a test switch valve at the lower end of the pipeline to introduce the oil and gas medium into the pipeline and then bring it out to the surface.

[0003] In existing gas spring-structured test valves, the gas spring functions by pre-charging with nitrogen at a certain pressure on the surface to offset the loss of compression torque due to high liquid column pressure in the downhole working environment. This prevents insufficient compression torque from hindering well opening and closing operations in the downhole environment. However, in ultra-deep well operations, due to excessively high liquid column pressures (typically exceeding 15,000 psi), the gas spring requires even higher pre-charging pressure on the surface. This significantly increases the safety risks to personnel and property during nitrogen charging on the surface and during surface testing before well entry. Furthermore, excessively high pre-charging pressure also increases the risk of leakage. Leakage can cause a decrease in pre-charging pressure, leading to a reduction in the gas spring compression torque and potentially resulting in valve malfunction or loss of function. Summary of the Invention

[0004] The purpose of this invention is to provide a gas spring structure for high temperature and high pressure environments, which reduces the pre-filled nitrogen pressure of the gas spring structure on the ground and improves operational safety.

[0005] The technical solution adopted in this invention is a gas spring structure for high temperature and high pressure environments, including a nitrogen chamber and an oil chamber connected to each other. The nitrogen chamber includes a nitrogen outer cylinder, one end of which is connected to an upper outer cylinder, and the other end is connected to the outer cylinder of the oil chamber. A nitrogen mandrel is arranged on the inner side of the nitrogen outer cylinder along the axial direction of the nitrogen outer cylinder. The nitrogen mandrel passes through the upper outer cylinder, and a chamber for containing nitrogen is formed between the nitrogen outer cylinder and the nitrogen mandrel. An upper pressure hole is opened on the nitrogen outer cylinder relative to the chamber position. The annular pressure enters the chamber through the upper pressure hole to realize the movement of the nitrogen mandrel.

[0006] An oil chamber mandrel is provided on the inner side of the outer cylinder of the oil chamber along the axial direction of the outer cylinder. An oil cavity is formed between the outer cylinder of the oil chamber and the oil chamber mandrel. The oil cavity is connected to the nitrogen chamber through an oil passage. A lower connector is connected to the outer cylinder of the oil chamber away from the nitrogen chamber.

[0007] The invention is further characterized in that,

[0008] The upper outer cylinder has a pin hole along its radial direction. A shear pin passes through the pin hole and is connected to the nitrogen chamber mandrel. A plug is provided at the end of the shear pin away from the nitrogen chamber mandrel and is connected to the upper outer cylinder.

[0009] The outer cylinder is also radially provided with a drain hole for removing accumulated liquid.

[0010] The nitrogen chamber mandrel has a pin groove, and one end of the shear pin is placed in the pin groove and engaged with the nitrogen chamber mandrel.

[0011] The chamber is equipped with a fixing ring and a sealing sleeve. The fixing ring and the sealing sleeve are sleeved on the outside of the nitrogen chamber mandrel. The sealing sleeve is threaded to the nitrogen chamber mandrel. The sealing sleeve limits and fixes the fixing ring. The pressure hole is located above the fixing ring.

[0012] A nitrogen chamber piston is also sleeved on the outside of the nitrogen chamber mandrel. The nitrogen chamber piston slides relative to the nitrogen chamber mandrel in the chamber. A boss is provided between the nitrogen chamber outer cylinder and the sealing sleeve to limit the movement distance of the nitrogen chamber mandrel driven by the sealing sleeve.

[0013] Nitrogen injection holes are radially opened on the outer cylinder of the nitrogen chamber. Nitrogen gas is injected between the sealing sleeve and the nitrogen chamber piston through the nitrogen injection holes. A protective plug is set on the outer cylinder of the nitrogen chamber relative to the nitrogen injection hole. A nitrogen injection plug is also set on the outer cylinder of the nitrogen chamber above the protective plug. The axis of the nitrogen injection plug is perpendicular to the axis of the protective plug. A locking screw is set at the end of the nitrogen injection plug along the axis perpendicular to the nitrogen injection plug. The locking screw is connected to the outer cylinder of the nitrogen chamber.

[0014] A metering sleeve is installed on the side of the oil chamber that connects to the nitrogen chamber. The oil in the oil chamber enters the pipeline through the metering sleeve. The metering sleeve is connected to the end of the nitrogen chamber piston away from the sealing sleeve through the pipeline.

[0015] An oil chamber piston is also installed inside the oil chamber. A pressure transmission hole is opened on the side of the outer cylinder of the oil chamber piston that is away from the metering sleeve. The annular pressure enters the oil chamber through the pressure transmission hole to control the sliding of the oil chamber piston relative to the oil chamber spindle. An oil injection plug is installed on the outer cylinder of the oil chamber. Oil is injected between the metering sleeve and the oil chamber piston through the oil injection plug.

[0016] The metering kit includes two parallel pipelines. One pipeline is equipped with a one-way constant pressure differential throttle valve, and the other pipeline is equipped with a one-way throttle valve. The one-way constant pressure differential throttle valve is located on the pipeline from the oil chamber to the nitrogen chamber.

[0017] The metering sleeve is provided with a retaining ring on each side to limit the position of the metering sleeve and a retaining ring to change the line contact to a surface contact. The retaining ring and the retaining ring are sleeved on the outside of the oil chamber spindle, and the retaining ring is engaged with the raised step on the outside of the oil chamber spindle.

[0018] The retaining ring is located between the metering sleeve and the oil chamber piston.

[0019] Sealing components are provided on both the upper and lower sides of the sealing sleeve, nitrogen chamber piston, metering sleeve, and oil chamber piston to ensure the sealing of the chamber and oil chamber.

[0020] The beneficial effects of this invention are:

[0021] (1) The gas spring structure of the present invention for high temperature and high pressure environment increases the volume of the nitrogen chamber, so that the pressure of nitrogen pre-filling on the ground does not need to be too high, thus ensuring operational safety, avoiding safety accidents, and reducing nitrogen leakage and safety risks caused by high pre-filling pressure.

[0022] (2) The gas spring structure of the present invention for high temperature and high pressure environment realizes the compression, energy storage and release of nitrogen in nitrogen chamber by setting a one-way constant pressure differential throttle valve and a one-way throttle valve in the metering sleeve, so as to ensure the normal operation of gas spring downhole; the working temperature range of the overall gas spring can reach -20℃~450℃, and the liquid column pressure can be greater than 20000psi. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the gas spring structure of the present invention for use in high temperature and high pressure environments;

[0024] Figure 2 yes Figure 1 A schematic diagram of the cross-sectional structure from view A in the middle;

[0025] Figure 3 This is a schematic diagram of the nitrogen chamber in the gas spring structure for high temperature and high pressure environments of the present invention;

[0026] Figure 4 This is a schematic diagram of the oil chamber in the gas spring structure of the present invention for use in high temperature and high pressure environments;

[0027] Figure 5 This is a schematic diagram of the principle structure of the metering sleeve in the gas spring structure for high temperature and high pressure environments of the present invention.

[0028] In the diagram, 1. Nitrogen chamber outer cylinder, 2. Fixing ring, 3. Sealing sleeve, 4. Nitrogen chamber piston, 5. Nitrogen chamber spindle, 6. Upper outer cylinder, 7. Shear pin, 8. Pin hole, 9. Pin groove, 10. Oil chamber outer cylinder, 11. Metering sleeve, 12. Retaining ring, 13. Retaining ring, 14. Oil injection plug, 15. Oil chamber spindle, 16. Oil chamber piston, 17. Sealing assembly, 18. Upper pressure transmission hole, 19. Lower pressure transmission hole, 20. Nitrogen injection plug, 21. Anti-reverse screw, 22. Lower connector, 23. Plug, 24. Drain hole, 25. One-way constant pressure differential throttle valve, 26. One-way throttle valve, 27. Protective plug, 28. Oil passage. Detailed Implementation

[0029] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0030] Example 1

[0031] like Figure 1 As shown, the gas spring structure of the present invention for high temperature and high pressure environments includes a nitrogen chamber and an oil chamber connected to each other. The nitrogen chamber includes a nitrogen outer cylinder 1, one end of which is connected to an upper outer cylinder 6, and the other end is connected to the outer cylinder 10 of the oil chamber. A nitrogen mandrel 5 is arranged on the inner side of the nitrogen outer cylinder 1 along the axial direction of the nitrogen outer cylinder 1. The nitrogen mandrel 5 passes through the upper outer cylinder 6, and a chamber for containing nitrogen is formed between the nitrogen outer cylinder 1 and the nitrogen mandrel 5. An upper pressure hole 18 is opened on the nitrogen outer cylinder 1 relative to the chamber position. The annular pressure enters the chamber through the upper pressure hole 18 to realize the movement of the nitrogen mandrel 5.

[0032] The upper outer cylinder 6 has a pin hole 8 along its radial direction. A shear pin 7 passes through the pin hole 8 and is connected to the nitrogen chamber mandrel 5 through the pin hole 8, forming an initial locked state. A plug 23 is provided at the end of the shear pin 7 away from the nitrogen chamber mandrel 5 to prevent the shear pin 7 from falling out of the pin hole 8 during transportation. The plug 23 is connected to the upper outer cylinder 6.

[0033] Furthermore, a pin groove 9 is formed on the nitrogen chamber mandrel 5, and one end of the shear pin 7 is placed in the pin groove 9 and engaged with the nitrogen chamber mandrel 5. This ensures that the nitrogen chamber mandrel 5 will not move when the overall gas spring structure is not in use.

[0034] The outer cylinder 6 is also radially provided with a drain hole 24 for removing accumulated liquid. Figure 1 As shown, there is an inclined surface at the contact surface between the nitrogen chamber mandrel 5 and the upper outer cylinder 6. When the nitrogen chamber mandrel 5 moves to the right, a cavity will exist between the upper outer cylinder 6 and the nitrogen chamber mandrel 5. Some liquid may enter the cavity through the gap. When the nitrogen chamber mandrel 5 moves to the left to reset, it cannot return to its initial position due to the presence of liquid. Even if it can return, it will take a long time to drain the liquid. Over time, the nitrogen chamber mandrel 5 will be unable to move. The drain hole 24 can quickly drain the liquid in the cavity when the nitrogen chamber mandrel 5 resets to the left, ensuring the movement of the nitrogen chamber mandrel 5.

[0035] An oil chamber spindle 15 is provided on the inner side of the outer cylinder 10 along the axial direction of the outer cylinder 10. An oil cavity is formed between the outer cylinder 10 and the oil chamber spindle 15. The oil cavity is connected to the nitrogen chamber through the oil passage 28. A lower pressure transmission hole 19 is opened on the outer cylinder 10. The annular pressure enters the nitrogen chamber and the oil chamber through the upper pressure transmission hole 18 and the lower pressure transmission hole 19, thereby controlling the reciprocating motion of the nitrogen chamber spindle 5. A lower connector 22 is connected to the end of the outer cylinder 10 away from the nitrogen chamber outer cylinder 1.

[0036] Example 2

[0037] This invention relates to a gas spring structure for use in high-temperature and high-pressure environments, comprising a nitrogen chamber and an oil chamber connected to each other. The nitrogen chamber includes a nitrogen outer cylinder 1, one end of which is connected to an upper outer cylinder 1, and the other end is connected to the outer cylinder 10 of the oil chamber. A nitrogen chamber mandrel 5 is arranged axially along the inner side of the nitrogen outer cylinder 1, passing through the upper outer cylinder 1. A nitrogen chamber chamber containing nitrogen is formed between the nitrogen outer cylinder 1 and the nitrogen chamber mandrel 5. A nitrogen chamber piston 4 is arranged in the chamber, sleeved on the outside of the nitrogen chamber mandrel 5, and the nitrogen chamber piston 4 can slide relative to the nitrogen chamber mandrel 5. An upper pressure hole 18 is opened on the nitrogen outer cylinder 1 relative to the chamber position. The annular pressure enters the chamber through the upper pressure hole 18 to realize the movement of the nitrogen chamber mandrel 5.

[0038] The upper outer cylinder 6 has a pin hole 8 along its radial direction. A shear pin 7 passes through the pin hole 8 and is connected to the nitrogen chamber mandrel 5 through the pin hole 8, forming an initial locked state. A plug 23 is provided at the end of the shear pin 7 away from the nitrogen chamber mandrel 5 to prevent the shear pin 7 from falling out of the pin hole 8 during transportation. The plug 23 is connected to the upper outer cylinder 6.

[0039] Furthermore, a pin groove 9 is formed on the nitrogen chamber mandrel 5, and one end of the shear pin 7 is placed in the pin groove 9 and engaged with the nitrogen chamber mandrel 5. This ensures that the nitrogen chamber mandrel 5 will not move when the overall gas spring structure is not in use. A drain hole 24 for draining accumulated liquid is also formed radially on the upper outer cylinder 6.

[0040] like Figure 4 As shown, an oil chamber spindle 15 is provided on the inner side of the outer cylinder 10 of the oil chamber along the axial direction of the outer cylinder 10 of the oil chamber. An oil cavity is formed between the outer cylinder 10 of the oil chamber and the oil chamber spindle 15. The oil cavity is connected to one end of the nitrogen chamber piston 4 through the oil passage 28. A metering sleeve 11 is provided on the side of the oil cavity connected to the nitrogen chamber piston 4. The oil in the oil cavity enters the oil passage 28 through the metering sleeve 11.

[0041] An oil chamber piston 16 is also provided inside the oil chamber. The lower pressure transmission hole 19 is opened on the side of the oil chamber piston 16 away from the metering sleeve 11. The annular pressure enters the oil chamber through the lower pressure transmission hole 19 to control the sliding of the oil chamber piston 16 relative to the oil chamber spindle 15. An oil injection plug 14 is provided on the outer cylinder 10 of the oil chamber. The oil is injected into the space between the metering sleeve 11 and the oil chamber piston 16 through the oil injection plug 14.

[0042] A retaining ring 12 and a retaining ring 13 are respectively provided on both sides of the metering sleeve 11 to limit its position. The retaining ring 12 and the retaining ring 13 are sleeved on the outside of the oil chamber spindle 15, and the retaining ring 12 is engaged with the raised step on the outside of the oil chamber spindle 15. The left end of the metering sleeve 11 forms a conical cavity with the outer cylinder 10 of the oil chamber. At this time, the left end of the metering sleeve 11 only forms line contact with the outer cylinder 10 of the oil chamber, and the stability of the metering sleeve 11 is poor. However, the retaining ring 13 is set in the conical cavity, which changes the line contact fixation of the left side of the metering sleeve 11 to surface contact fixation, which greatly improves the stability of the left side of the metering sleeve 11 and avoids displacement of the metering sleeve due to the pressure difference between the two ends of the metering sleeve 11, thus affecting the overall operation of the gas spring. The retaining ring 12 is located between the metering sleeve 11 and the oil chamber piston 16, that is, the oil injected through the oil injection plug 14 is located between the retaining ring 12 and the oil chamber piston 16. The end of the outer cylinder 10 of the oil chamber away from the outer cylinder 1 of the nitrogen chamber is connected to a lower connector 22.

[0043] like Figure 5 As shown, the metering kit 11 includes two parallel pipelines. One pipeline is equipped with a one-way constant pressure differential throttle valve 25, and the other pipeline is equipped with a one-way throttle valve 26. The one-way constant pressure differential throttle valve 25 is located on the pipeline from the oil chamber to the nitrogen chamber.

[0044] When the oil in the oil chamber flows towards the nitrogen chamber spindle 5, the pressure difference across the one-way differential pressure throttle valve 25 needs to reach a set value before the valve opens. This allows the oil in the oil chamber to pass through the oil passage 28 via the throttling effect of the one-way differential pressure throttle valve 25, thus pushing the nitrogen chamber piston 4 to move. The set pressure difference of the one-way differential pressure throttle valve 25 can be adjusted as needed to ensure that when the annular pressure is initially applied, the sealing sleeve 3 has sufficient force to drive the nitrogen chamber spindle 5 to the right. After the annular pressure is released, the oil entering the nitrogen chamber can only slowly return to the oil chamber due to the throttling effect of the one-way throttle valve 26. The pressure released by the pressurized nitrogen in the chamber pushes the sealing sleeve 3 to drive the nitrogen chamber spindle 5 to the left, thereby realizing the reciprocating motion of the nitrogen chamber spindle 5.

[0045] Example 3

[0046] This embodiment is based on embodiment 2, such as Figure 3 As shown, a fixing ring 2 and a sealing sleeve 3 are provided in the nitrogen chamber. The fixing ring 2 and the sealing sleeve 3 are sleeved on the outside of the nitrogen chamber spindle 5. The sealing sleeve 3 is threadedly connected to the nitrogen chamber spindle 5. The sealing sleeve 3 limits and fixes the fixing ring 2. The pressure hole 18 is located above the fixing ring 2.

[0047] Specifically, a step is provided on the left side of the nitrogen chamber mandrel 5 relative to the fixed ring 2. One side of the fixed ring 2 is brought into contact with the step, and the sealing sleeve 3 is rotated at the same time. As the sealing sleeve 3 and the nitrogen chamber mandrel 5 are connected, the sealing sleeve 3 applies pressure to one side of the fixed ring 2. One side of the fixed ring 2 is restricted by the step of the nitrogen chamber mandrel 5, and the other side is squeezed by the sealing sleeve 3, thereby achieving limiting and fixing. The annular pressure enters through the pressure hole 18, causing the fixed ring 2, the sealing sleeve 3 and the nitrogen chamber mandrel 5 to move as a whole.

[0048] A boss is provided between the outer cylinder 1 of the nitrogen chamber and the sealing sleeve 3 to limit the movement distance of the nitrogen chamber spindle 5 driven by the sealing sleeve 3, so as to facilitate the control of the reciprocating movement distance of the nitrogen chamber spindle 5.

[0049] like Figure 2 As shown, a nitrogen injection hole is radially opened on the outer cylinder 1 of the nitrogen chamber. Nitrogen gas is injected between the sealing sleeve 3 and the nitrogen chamber piston 4 through the nitrogen injection hole. A protective plug 27 is provided on the outer cylinder 1 of the nitrogen chamber opposite to the nitrogen injection hole. A nitrogen injection plug 20 is also provided on the outer cylinder 1 of the nitrogen chamber below the protective plug 27. The axis of the nitrogen injection plug 20 is perpendicular to the axis of the nitrogen injection hole. A retaining screw 21 is provided at the end of the nitrogen injection plug 20 along the axis perpendicular to the nitrogen injection plug 20. The retaining screw 21 is connected to the outer cylinder 1 of the nitrogen chamber.

[0050] After nitrogen is injected into the nitrogen chamber through the nitrogen injection hole, the nitrogen injection hole is sealed with a protective plug 27, and then a nitrogen injection plug 20 is inserted for further sealing. The nitrogen injection plug 20 is prevented from falling off the outer cylinder 1 of the nitrogen chamber by a retaining screw 21.

[0051] Sealing components 17 are provided on both the upper and lower sides of the sealing sleeve 3, nitrogen chamber piston 4, metering sleeve 11, and oil chamber piston 16. The sealing components 17 ensure the sealing performance of the chamber, oil chamber, and annulus. The sealing components 17 can be any sealing element that can achieve a sealing effect, such as a sealing ring.

[0052] The gas spring structure of this invention for high temperature and high pressure environments injects nitrogen into the chamber through the nitrogen injection hole, so that there is a certain pressure of nitrogen in the chamber, so that the gas pressure in the chamber and the pressure of the annular liquid column are as balanced as possible. At the same time, a certain amount of oil is injected into the oil chamber, and the shear pin 7 is inserted into the pin hole 8 and connected to the upper outer cylinder 6 through the plug 23 to prevent the shear pin 7 from falling out of the pin hole 8.

[0053] The annular pressure is increased, and the pressure enters the nitrogen chamber and oil chamber from the upper pressure port 18 and lower pressure port 19 respectively, pushing the sealing sleeve 3 and the oil chamber piston 16 to move towards each other, thereby shearing the shear pin 7. Because the boss restricts the movement path of the sealing sleeve 3, the sealing sleeve 3 can only move a short distance, and the nitrogen pressure in the chamber increases only slightly due to the movement of the sealing sleeve 3. At this time, the metering sleeve 11 is not yet compressed or only slightly compressed. Due to the action of the one-way constant pressure differential throttle valve 25, the oil in the oil chamber cannot immediately enter the oil passage 28 through the metering sleeve 11, thus ensuring that the sealing sleeve 3 drives the movement of the nitrogen chamber mandrel 5. Usually, when the annular pressure increases to the set value, the nitrogen chamber mandrel 5 also moves to the designated position.

[0054] Maintaining the annular pressure, the sealing sleeve 3 is restricted and cannot move further, and the nitrogen in the chamber is no longer compressed. At this time, a significant pressure difference appears on both sides of the metering sleeve 11, that is, the annular pressure is greater than the gas pressure in the chamber. The one-way constant pressure differential throttle valve 25 opens, and the oil in the oil chamber slowly passes through the metering sleeve 11 into the oil passage 28, reaching one end of the nitrogen chamber piston 4, pushing the nitrogen chamber piston 4 to compress the nitrogen in the chamber until the gas pressure in the chamber and the annular pressure reach equilibrium.

[0055] When the applied annular pressure is removed, due to the presence of the one-way throttle valve 26, the oil entering one end of the nitrogen chamber piston 4 can only slowly return to the oil chamber through the one-way throttle valve 26. Therefore, the pressure of the compressed nitrogen in the chamber cannot be quickly released by pushing the nitrogen chamber piston 4; instead, it can only quickly push the sealing sleeve 3 away from the nitrogen chamber piston 4, simultaneously driving the nitrogen chamber spindle 5 to the limit point, maximizing the movement of the nitrogen chamber spindle 5 by the pressure released from the chamber. Because the movement path of the sealing sleeve 3 is short, the pressure drop generated in the nitrogen chamber is very small when the annular pressure is removed. At this time, the pressure in the chamber can still push the nitrogen chamber piston 4, causing the oil to slowly return to the oil chamber through the metering sleeve 11 until the pressure in the chamber and the annular pressure reach equilibrium. Repeating the application and removal of the annular pressure achieves the reciprocating motion of the nitrogen chamber spindle 5.

Claims

1. A gas spring structure for use in high temperature and high pressure environments, characterized in that, It includes a nitrogen chamber and an oil chamber connected to each other. The nitrogen chamber includes a nitrogen chamber outer cylinder (1). One end of the nitrogen chamber outer cylinder (1) is connected to an upper outer cylinder (6), and the other end is connected to the outer cylinder (10) of the oil chamber. A nitrogen chamber mandrel (5) is arranged on the inner side of the nitrogen chamber outer cylinder (1) along the axial direction of the nitrogen chamber outer cylinder (1). The nitrogen chamber mandrel (5) passes through the upper outer cylinder (6). A chamber for containing nitrogen is formed between the nitrogen chamber outer cylinder (1) and the nitrogen chamber mandrel (5). An upper pressure hole (18) is opened in the nitrogen chamber outer cylinder (1) relative to the chamber position. The annular pressure enters the chamber through the upper pressure hole (18) to realize the movement of the nitrogen chamber mandrel (5). An oil chamber spindle (15) is provided on the inner side of the outer cylinder (10) along the axial direction of the outer cylinder (10). An oil cavity is formed between the outer cylinder (10) and the oil chamber spindle (15). The oil cavity is connected to the nitrogen chamber through the oil passage (28). A lower connector (22) is connected to the outer cylinder (1) of the outer cylinder (1) away from the nitrogen chamber. The upper outer cylinder (6) has a pin hole (8) radially opened on its upper side. A shear pin (7) passes through the pin hole (8). The shear pin (7) passes through the pin hole (8) and is connected to the nitrogen chamber mandrel (5). A plug (23) is provided at the end of the shear pin (7) away from the nitrogen chamber mandrel (5). The plug (23) is connected to the upper outer cylinder (6). The upper outer cylinder (6) is also radially provided with a drain hole (24) for draining accumulated liquid. The chamber is provided with a fixing ring (2) and a sealing sleeve (3). The fixing ring (2) and the sealing sleeve (3) are sleeved on the outside of the nitrogen chamber mandrel (5). The sealing sleeve (3) is threadedly connected to the nitrogen chamber mandrel (5). The fixing ring (2) is limited and fixed by the sealing sleeve (3). The pressure hole (18) is located above the fixing ring (2). A nitrogen chamber piston (4) is also sleeved on the outside of the nitrogen chamber mandrel (5). The nitrogen chamber piston (4) slides relative to the nitrogen chamber mandrel (5) in the chamber. A boss is provided in the outer cylinder (1) of the nitrogen chamber to limit the movement distance of the nitrogen chamber mandrel (5) driven by the sealing sleeve (3) between the sealing sleeve (3) and the nitrogen chamber piston (4). The outer cylinder (1) of the nitrogen chamber has a nitrogen injection hole in the radial direction. Nitrogen gas is injected between the sealing sleeve (3) and the nitrogen chamber piston (4) through the nitrogen injection hole. A protective plug (27) is provided on the outer cylinder (1) of the nitrogen chamber relative to the nitrogen injection hole. A nitrogen injection plug (20) is also provided on the outer cylinder (1) of the nitrogen chamber above the protective plug (27). The axial direction of the nitrogen injection plug (20) is perpendicular to the axial direction of the protective plug (27). A locking screw (21) is provided at the end of the nitrogen injection plug (20) along the axial direction perpendicular to the nitrogen injection plug (20). The locking screw (21) is connected to the outer cylinder (1) of the nitrogen chamber. A metering sleeve (11) is provided on the side of the oil chamber that connects to the nitrogen chamber. The oil in the oil chamber enters the pipeline through the metering sleeve (11). The metering sleeve (11) is connected to the end of the nitrogen chamber piston (4) away from the sealing sleeve (3) through the pipeline. An oil chamber piston (16) is also provided in the oil chamber. A lower pressure transmission hole (19) is opened on the side of the outer cylinder (10) of the oil chamber relative to the oil chamber piston (16) away from the metering sleeve (11). The annular pressure enters the oil chamber through the lower pressure transmission hole (19) to control the oil chamber piston (16) to slide relative to the oil chamber spindle (15). An oil injection plug (14) is provided on the outer cylinder (10) of the oil chamber. The oil is injected into the space between the metering sleeve (11) and the oil chamber piston (16) through the oil injection plug (14). The metering sleeve (11) includes two parallel pipelines. One pipeline is equipped with a one-way constant pressure differential throttle valve (25), and the other pipeline is equipped with a one-way throttle valve (26). The one-way constant pressure differential throttle valve (25) is located on the pipeline from the oil chamber to the nitrogen chamber. The metering sleeve (11) is provided with a retaining ring (12) for limiting the position of the metering sleeve (11) and a retaining ring (13) for changing the line contact to a surface contact on both sides. The retaining ring (12) and the retaining ring (13) are sleeved on the outside of the oil chamber spindle (15). The retaining ring (12) is engaged with the protruding step on the outside of the oil chamber spindle (15).

2. The gas spring structure for high temperature and high pressure environments according to claim 1, characterized in that, The nitrogen chamber mandrel (5) has a pin groove (9), and one end of the shear pin (7) is placed in the pin groove (9) and engaged with the nitrogen chamber mandrel (5).

3. The gas spring structure for high temperature and high pressure environments according to claim 1, characterized in that, The retaining ring (12) is located between the metering sleeve (11) and the oil chamber piston (16).

4. The gas spring structure for high temperature and high pressure environments according to claim 1, characterized in that, The sealing sleeve (3), nitrogen chamber piston (4), metering sleeve (11) and oil chamber piston (16) are all provided with sealing components (17) on the upper and lower sides, and the sealing components (17) ensure the sealing of the chamber and the oil chamber.

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