A high pressure oil and gas well closed annular pressure control tool

Abstract

The application discloses a high-pressure oil and gas well sealed annular pressure control tool, a lower joint is fixedly sleeved at one end of an inner cylinder, a sealing limiting cylinder is fixedly connected at the other end of the inner cylinder, an end threaded connecting pipe, a pin cylinder, a middle threaded connecting pipe, a blocking ring cylinder and an outer cylinder are fixedly sleeved on the outer lateral wall of the inner cylinder in horizontal direction, and the outer cylinder is fixedly connected with a pressure balance pipe column; a chamber opening valve is arranged on the outer lateral wall of the pressure balance pipe column, a chamber is arranged and provided with the chamber opening valve, and the chamber opening valve is composed of an upper valve body, an upper plug column, an upper shear pin, a lower shear pin and a lower plug column. The application solves the problems of annular pressure sudden change and oil pipe deformation of the downhole double packer.

Description

Technical Field

[0001] This invention belongs to the technical field of downhole tools for oil and gas field testing and completion, specifically relating to a pressure control tool for the closed annulus of high-pressure oil and gas wells. Background Technology

[0002] In ultra-deep well completion strings with a dual-packer structure, the annulus between the packers remains sealed. During oil well production, oil production in the tubing increases the temperature of the fluid inside the tubing. Due to temperature transfer, the fluid volume in the sealed annulus between the packers expands due to heat, causing the annulus pressure to rise. During acidizing in oil and gas wells, the tubing fluid temperature is lower than the annulus fluid temperature. Due to temperature transfer, the fluid volume in the sealed annulus between the packers is compressed due to cold, causing the annulus pressure to decrease. When the external pressure of the tubing is greater than the internal pressure, the tubing's resistance to external extrusion decreases; when the internal pressure of the tubing is greater than the external pressure, the tubing's resistance to internal pressure decreases. Simultaneously, a sudden increase or decrease in annulus pressure leads to a larger pressure difference across the packers, which in severe cases can cause tubing failure and packer seal failure, affecting the normal operation of the oil and gas well.

[0003] Currently, most solutions to the problem of sudden changes in annular pressure between dual packers use rupture discs. When the pressure difference between the inside and outside of the tubing increases to the set value of the rupture disc, the rupture disc bursts, releasing the annular pressure. However, the rupture disc needs to be replaced after each rupture and cannot be reused. Moreover, the rupture disc does not take into account the problem of tubing deformation caused by temperature changes during liquid flow. Summary of the Invention

[0004] The purpose of this invention is to provide a high-pressure oil and gas well closed annulus pressure control tool, which solves the problems of sudden annulus pressure change and tubing deformation in downhole dual packers.

[0005] To achieve the above objectives, this invention provides a high-pressure oil and gas well closed annulus pressure control tool, which adopts the following technical solution:

[0006] A high-pressure oil and gas well closed annulus pressure control tool includes: a tubing deformation compensation component and a pressure balancing component; the tubing deformation compensation component includes: an inner cylinder with a hollow cylindrical structure, the two ends of the inner cylinder being the lower end and the upper end of the inner cylinder, a lower connector fixedly sleeved at the lower end of the inner cylinder, a sealing limiting cylinder fixedly installed at the upper end of the inner cylinder, and adjacent to the lower connector, on the outer wall of the inner cylinder, a threaded connecting pipe at the end, a pin cylinder, the upper end of the threaded connecting pipe in the middle, a retaining ring cylinder, the lower end of the threaded connecting pipe in the middle, and an outer cylinder are sequentially fixedly sleeved.

[0007] The lower connector has a hollow internal structure and is fixedly connected to the inner cylinder by a lower anti-reverse screw.

[0008] The end threaded connecting pipe has a hollow cylindrical structure. The end threaded connecting pipe is fixedly sleeved on the outer wall of the inner cylinder. The inside of the end threaded connecting pipe cylinder is full of threads. One end of the end threaded connecting pipe is fixedly connected to the lower connector, and the other end of the end threaded connecting pipe is fixedly connected to the pin cylinder.

[0009] The pin cylinder has a hollow cylindrical structure with six evenly distributed pin holes in the center of the cylinder. The pin cylinder is fixedly connected to the inner cylinder by large shear pins.

[0010] The central threaded connecting pipe has a hollow cylindrical structure. The central threaded connecting pipe is divided into an upper central threaded connecting pipe and a lower central threaded connecting pipe. The cylinder is covered with threads. The lower central threaded connecting pipe is fixedly connected to the pin cylinder. The lower central threaded connecting pipe is also fixedly connected to the lower central threaded connecting pipe through a retaining ring cylinder.

[0011] The outer cylinder has a lower end and an upper end at its two ends. The lower end of the outer cylinder is fixedly connected to the upper end of the threaded connecting pipe in the middle, and the upper end of the outer cylinder is fixedly connected to the pressure balance pipe column by a lower anti-reverse screw.

[0012] The sealing and limiting cylinder has a hollow cylindrical structure, and a limiting ring is fitted on the outer wall of the sealing and limiting cylinder to limit the inner cylinder.

[0013] The pressure balancing components include:

[0014] A chamber opening valve is installed on the side wall of the pressure balancing tubing. The chamber opening valve consists of an upper valve body, an upper plug, an upper shear pin, a chamber, a lower shear pin, and a lower plug. The lower plug is first inserted into the chamber opening valve and fixed by the lower shear pin. Then the upper plug is fixed above the lower plug in the same way by the upper shear pin.

[0015] When in use:

[0016] When the external pressure of the tubing is greater than the internal pressure, the upper shear pin of the pressure balancing assembly shears off, the upper plug moves down, connecting the chamber to the outside, increasing the volume of the external annulus, and reducing the annulus pressure. When the temperature rises and causes the tubing to be subjected to excessive force, the large shear pin installed on the pin cylinder is sheared off by the external force, the inner cylinder and the outer cylinder are disconnected, the position of the outer cylinder remains unchanged, and the inner cylinder is stretched according to the force on the tubing, reducing the force on the tubing and preventing the tubing from deforming.

[0017] When the pressure inside the tubing is greater than the pressure outside the tubing, the lower shear pin of the pressure balancing assembly shears off, the lower plug moves upward, connecting the inside of the tubing to the chamber, reducing the pressure inside the tubing; when the temperature drops, causing the force on the tubing to become too great, the large shear pin installed on the pin cylinder is sheared off by the external force, the inner cylinder and outer cylinder are disconnected, the position of the outer cylinder remains unchanged, and the inner cylinder shortens according to the force on the tubing, reducing the force on the tubing and avoiding tubing damage and packer failure.

[0018] Preferably, the lower end of the inner cylinder has symmetrical threaded holes that match the pin holes on the pin cylinder; the upper end of the inner cylinder has threads, and the inner cylinder is nested inside the outer cylinder.

[0019] Preferably, the lower connector is fixedly connected to the inner cylinder by a lower anti-reverse screw.

[0020] Preferably, symmetrical threaded holes are provided on the outer cylinder, which are matched with symmetrical threaded holes on the pressure balance column by a lower anti-reverse screw.

[0021] Preferably, the upper plunger, upper valve body, and pressure balance column are interference-fitted and limited by upper and lower shear pins.

[0022] The beneficial effects of this invention are:

[0023] (1) Based on the working principle of the fractured disc, when the pressure difference between the inside and outside of the tubing reaches the set value of the pressure balancing component due to oil and gas well production or acidizing, the pressure balancing component automatically adjusts the annular fluid volume by opening the valve in the middle chamber, thereby increasing or decreasing the annular pressure and ensuring that the pressure difference between the inside and outside of the annulus varies within a certain range and does not exceed the limit value. At the same time, the pressure balancing component can be repeatedly used to balance the pressure of the sealed annulus when the pressure difference between the inside and outside of the tubing reaches the set value.

[0024] (2) When the temperature changes during the production or acidizing process of oil and gas wells cause the tubing to deform due to temperature effect, and the pressure changes cause the tubing to deform due to bulging effect, the inner cylinder of the tubing deformation compensation component is stretched or shortened according to the force on the tubing string. The deformation of the tubing deformation compensation component reduces the force on the tubing and avoids tubing deformation.

[0025] (3) The present invention uses a pressure balancing component and a tubing deformation compensation component together. Under the condition that the annular medium is not changed, the pressure balancing component adjusts the annular volume to increase or decrease the annular pressure, balances the closed annular pressure between the two packers, reduces the pressure difference between the packers, and avoids packer failure. At the same time, the annular temperature change produces a temperature deformation effect on the tubing, and the pressure change produces an expansion effect deformation on the tubing. The extension or shortening of the inner cylinder in the tubing deformation compensation component reduces the stress on the tubing and reduces tubing damage. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0027] Figure 2 This is a schematic diagram of the tubular deformation compensation component of the present invention;

[0028] Figure 3 This is a schematic diagram of the pressure balancing component of the present invention;

[0029] Figure 4 Figure AA shows the overall structural cross-section of the present invention (Figure (a) is an assembly diagram of the lower connector, end threaded connecting pipe, and pin cylinder; (b) is an assembly diagram of the middle threaded connecting pipe, retaining ring cylinder, and sealing cylinder of the present invention; (c) is a schematic diagram of the pressure balance tubing structure of the present invention).

[0030] Figure 5 This is a schematic diagram of the lower connector structure of the present invention;

[0031] Figure 6 This is a schematic diagram of the end threaded connection tube of the present invention;

[0032] Figure 7 This is a schematic diagram of the pin cylinder of the present invention;

[0033] Figure 8 This is a schematic diagram of the retaining ring cylinder structure of the present invention;

[0034] Figure 9 This is a schematic diagram of the sealing and limiting cylinder structure of the present invention;

[0035] Figure 10 This is a schematic diagram of the upper valve body structure of the present invention;

[0036] Figure 11 This is a schematic diagram of the upper plug structure of the present invention;

[0037] Figure 12 This is a schematic diagram of the chamber opening valve structure of the present invention.

[0038] The components are: 1. Lower connector, 2. Lower anti-reverse screw, 3. End threaded connecting pipe, 4. Pin cylinder, 5. Large shear pin, 6. Middle threaded connecting pipe, 7. Retaining ring cylinder, 8. Outer cylinder, 9. Inner cylinder, 10. Sealing and limiting cylinder, 11. Pressure balancing string, 13. Upper valve body, 14. Upper plug, 15. Upper shear pin, 16. Upper connector, 17. Lower shear pin, 18. Lower plug, 19. Sealing ring, 20. Limiting ring, 21. Chamber opening valve, 22. Chamber. Detailed Implementation

[0039] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0040] Example 1

[0041] like Figure 1-3 As shown, a high-pressure oil and gas well closed annulus pressure control tool includes a tubing deformation compensation component and a pressure balancing component.

[0042] The tubing deformation compensation components include a lower connector 1, a lower anti-reverse screw 2, an end threaded connecting pipe 3, a pin cylinder 4, a large shear pin 5, a middle threaded connecting pipe 6, a retaining ring cylinder 7, an outer cylinder 8, an inner cylinder 9, a sealing limit cylinder 10, and a sealing rubber ring 19.

[0043] The inner cylinder 9 has a hollow cylindrical structure to ensure liquid flow. The two ends of the inner cylinder 9 are the lower end and the upper end, respectively. A lower connector 1 is fixedly fitted onto the lower end of the inner cylinder 9, and a sealing and limiting cylinder 10 is fixedly connected to the upper end. On the outer wall of the inner cylinder 9, in the horizontal direction, an end threaded connecting pipe 3, a pin cylinder 4, a middle threaded connecting pipe 6, a retaining ring cylinder 7, and an outer cylinder 8 are sequentially fixedly fitted. The outer cylinder 8 and the sealing and limiting cylinder 10 have reserved space for the movement of the inner cylinder 9. The outer cylinder 8 is fixedly connected to a pressure balance column 11.

[0044] The lower end of the inner cylinder 9 has three pairs of symmetrical threaded holes that match the six pin holes evenly distributed around the circumference in the middle of the pin cylinder 4. The end of the inner cylinder 9 has threads, and the upper end of the inner cylinder 9 is fixedly connected to the sealing and limiting cylinder 10 by threads.

[0045] like Figure 4 Figure a in the middle and Figure 5 As shown, the lower connector 1 has a hollow internal structure to ensure fluid flow. One end has symmetrical threaded holes, and the other end of the lower connector 1 is fixedly fitted onto the oil pipe. The end with the symmetrical threaded holes is fitted onto the oil pipe through the inner cylinder 9. The lower connector 1 and the inner cylinder 9 are fixedly connected by the lower anti-reverse screw 2.

[0046] like Figure 6 As shown, the end threaded connecting pipe 3 has a hollow cylindrical structure to ensure liquid flow. The interior of the cylindrical part of the end threaded connecting pipe 3 is covered with threads. The end threaded connecting pipe 3 is fixedly sleeved on the outer wall of the inner cylinder 9. One end of the end threaded connecting pipe 3 is threadedly connected to the end of the lower connector 1 with symmetrical threaded holes. The other end of the end threaded connecting pipe 3 is connected to one end of the pin cylinder 4 through threads.

[0047] like Figure 7 As shown, the pin cylinder 4 has a hollow cylindrical structure. Both ends of the pin cylinder 4 are threaded, and six pin holes are evenly distributed around its circumference in the middle. The pin cylinder 4 is connected to the inner cylinder 9 via a large shear pin 5. When this high-pressure oil and gas well closed annular pressure control tool is in operation, the large shear pin 5 disconnects, and the inner cylinder 9 can extend or shorten according to the stress on the tubing, reducing the stress on the tubing.

[0048] like Figure 4As shown in Figure b, the central threaded connecting pipe 6 has a hollow cylindrical structure to ensure liquid flow. The interior of the central threaded connecting pipe 6 is covered with threads. The central threaded connecting pipe 6 consists of an upper end and a lower end. The lower end of the central threaded connecting pipe 6 is threadedly fixed to the pin cylinder 4. Figure 8 As shown, the retaining ring cylinder 7 has threads at both ends, and the retaining ring cylinder 7 connects the upper end of the middle threaded connecting pipe 6 to the lower end of the middle threaded connecting pipe 6. The upper end of the middle threaded connecting pipe 6 is fixedly connected to one end of the outer cylinder 8 through threads.

[0049] like Figure 9 As shown, the sealing and limiting cylinder 10 has a hollow cylindrical structure. The sealing and limiting cylinder 10 is threaded inside. The sealing and limiting cylinder 10 is fixedly connected to the other end of the inner cylinder 9 by the thread. A limiting ring 20 is fixedly sleeved on the outer wall of the sealing cylinder 10. An annular groove is provided on the outer wall of the limiting ring 20. A sealing rubber ring 19 is provided on the annular groove. The sealing rubber ring 19 fits with the sealing and limiting cylinder 10 to ensure that the inner cylinder 9 and the outer cylinder 8 are sealed. The limiting ring 20 is fixedly sleeved on the sealing and limiting cylinder 10 to ensure that the sealing and limiting cylinder 10 is installed on the inner cylinder 9 through the thread at the end of the inner cylinder 9. The outer cylinder 8 is connected to the pressure balance column by the lower anti-reverse screw 2. The other end of the outer cylinder 8 is fixedly connected to the upper end of the threaded connecting pipe 6.

[0050] Three fluororubber sealing rings 19 are installed on the limiting ring 20. These sealing rings 19 can expand after installation. The sealing rings 19, the limiting ring 20, and the sealing limiting cylinder 10 are interference-fitted, fixing the sealing rings 19 within the annular groove to ensure that the sealing rings 19 will not move axially during movement. The limiting ring 20 ensures that the inner cylinder 9 does not exceed the design dimensions when stretched, thus guaranteeing the integrity of the tool.

[0051] The outer cylinder 8 has threads on its inner wall, and one end of the outer cylinder 8 has symmetrical threaded holes that mate with symmetrical threaded holes on the pressure balance column 11. The outer cylinder 8 and the pressure balance column 11 are fixedly connected by a lower anti-reverse screw 2. The other end of the outer cylinder 8 is threaded to the upper end of the central threaded connecting pipe 6.

[0052] like Figure 4 As shown in Figure c, the pressure balancing component includes: a pressure balancing tubing 11, a chamber opening valve 21, a chamber 22, and an upper connector 16. The pressure balancing tubing 11 is a hollow tubing structure, used to balance the pressure by adjusting the volume of the annular liquid.

[0053] like Figures 10-12 As shown, a chamber opening valve 21 is provided on the side wall of the pressure balance tubing 11. The chamber opening valve 21 consists of a lower stop screw 2, an upper valve body 13, an upper plug 14, an upper shear pin 15, a lower shear pin 17, a chamber 22, and a lower plug 18.

[0054] First, the lower plug 18 is inserted into the chamber opening valve 21 and fixed with the lower shear pin 17. Then, the upper plug 14 is fixed above the lower plug 18 in the same way with the upper shear pin 15. The upper plug 14 is interference-fitted with the upper valve body 13 and the pressure balancing column 11, and is limited by the upper shear pin 15 and the lower shear pin 17. Finally, the gap between the pressure balancing column 11 and the chamber opening valve 21 is welded to ensure its airtightness. When the annular pressure changes, the chamber opening valve 21 can open the chamber 22 according to the annular pressure change, and maintain annular pressure balance by automatically adjusting the annular volume.

[0055] The upper connector 16 is connected to the other end of the oil pipe, and the lower connector 1 is connected to one end of the oil pipe, so that the oil pipe forms a complete passage.

[0056] The working method of the high-pressure oil and gas well closed annulus pressure control tool of the present invention:

[0057] The high-pressure oil and gas well closed annular pressure control tool is installed on the tubing. When the oil and gas well is not in operation, the chamber opening valve 21 is closed, and the inner cylinder 9 is embedded inside the outer cylinder 8 and remains relatively stationary.

[0058] The installation method of the high-pressure oil and gas well closed annulus pressure control tool is as follows: First, connect the lower connector 1 to one end of the tubing, then connect one end of the inner cylinder 9 to the other end of the lower connector 1. An end threaded connecting pipe 3 is fitted onto the outer wall of the inner cylinder 9. One end of the end threaded connecting pipe 3 is connected to the lower connector 1. The end threaded connecting pipe 3 is threadedly fixed to the pin cylinder 4. The pin cylinder 4 is threadedly fixed to the inner thread of the middle threaded connecting pipe 6. The pin cylinder 4 is connected to the inner cylinder 9 through a large shear pin 5. The lower end of the middle threaded connecting pipe 6 is threadedly fixed to the retaining ring cylinder 7. The upper end of the threaded connecting pipe 6 in the middle is threadedly fixed to the other end of the retaining ring cylinder 7. The sealing and limiting cylinder 10 is threadedly fixed to the other end of the inner cylinder 9. The sealing and limiting cylinder 10 is installed at the end of the inner cylinder 9. After all the installations are completed, the outer cylinder 8 is inserted. One end of the outer cylinder 8 is threadedly fixed to the upper end of the threaded connecting pipe 6 in the middle. The other end of the outer cylinder 8 is fixedly connected to the upper threaded hole of the pressure balance pipe column 11 through the threaded hole and the lower anti-reverse screw 2. Finally, the upper connector 16 is fixedly connected to the other end of the oil pipe to form a complete passage for the oil pipe.

[0059] During oil well production, oil production from the tubing causes the temperature of the liquid inside the tubing to rise. Affected by the high-temperature liquid inside the tubing, the liquid volume in the sealed annulus between the two packers expands due to heat, increasing the pressure in the sealed annulus. When the external pressure in the tubing exceeds the internal pressure, the upper shear pin 15 of the pressure balancing assembly shears off, and the upper plug 14 moves downward, connecting the chamber 22 to the outside, increasing the volume of the external annulus and reducing the annulus pressure. When the temperature rise causes excessive force on the tubing, the large shear pin 5 installed on the pin cylinder 4 is sheared off by external force, disconnecting the inner cylinder 9 from the outer cylinder 8. The position of the outer cylinder 8 remains unchanged, while the inner cylinder 9 stretches according to the force on the tubing, reducing the force on the tubing and preventing tubing deformation.

[0060] During acidizing of oil and gas wells, the temperature of the tubing fluid is lower than that of the annulus fluid. Due to temperature transfer, the fluid volume in the sealed annulus between the two packers is compressed due to the cold, resulting in a decrease in the pressure of the sealed annulus. When the pressure inside the tubing is greater than the pressure outside the tubing, the lower shear pin 17 of the pressure balancing assembly shears off, and the lower plug 18 moves upward, connecting the inside of the tubing to the chamber 22, reducing the pressure inside the tubing. Through the pressure balancing assembly, the pressure difference between the inside and outside of the annulus is ensured to vary within a certain range and not exceed the limit value, reducing tubing deformation and packer failure. When the temperature decreases, causing excessive force on the tubing, the large shear pin 5 installed on the pin cylinder 4 is sheared off by external force, the inner cylinder 9 is disconnected from the outer cylinder 8, the position of the outer cylinder 8 remains unchanged, and the inner cylinder 9 shortens according to the force on the tubing, reducing the force on the tubing and avoiding tubing damage and packer failure.

[0061] A sealing and limiting cylinder 10 is threaded onto the end of the inner cylinder 9. The sealing and limiting cylinder 10 has a groove, and both a limiting ring 20 and the groove are present on it. Three fluororubber sealing rings 19 are installed on the sealing and limiting cylinder 10 through the groove. After installation, the sealing rings 19 expand, ensuring there are no gaps between the inner cylinder 9 and the outer cylinder 8, preventing liquid from flowing into the space between them. In conjunction with the limiting rings 20, this ensures that the deformation compensation component of the tubing does not exceed the design dimensions, guaranteeing that the inner cylinder 9 operates within the safe design range without failure, and ensuring the integrity of the tool structure.

[0062] This invention relates to a high-pressure oil and gas well closed annulus pressure control tool. This tool uses a tubing deformation compensation component and a pressure balancing component in conjunction. Without changing the annulus medium, the pressure balancing component self-adjusts the annulus volume to increase or decrease the annulus pressure, balancing the closed annulus pressure between the two packers, reducing the pressure difference between the packers, and preventing packer failure. Simultaneously, annulus temperature changes cause temperature deformation of the tubing, and pressure changes cause expansion deformation. The tubing stress is reduced by the elongation or shortening of the inner cylinder in the tubing deformation compensation component, thus minimizing tubing damage.

[0063] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A tool for controlling the closed annulus pressure of high-pressure oil and gas wells, characterized in that, include: Tubing deformation compensation components and pressure balancing components; The tubular deformation compensation component includes: The inner cylinder (9) has a hollow cylindrical structure. The two ends of the inner cylinder (9) are the lower end of the inner cylinder (9) and the upper end of the inner cylinder (9), respectively. The lower end of the inner cylinder (9) is fixedly fitted with a lower connector (1). The upper end of the inner cylinder (9) is fixedly fitted with a sealing limiting cylinder (10). The lower connector (1) is adjacent to the outer wall of the inner cylinder (9) and the end threaded connecting pipe (3), the pin cylinder (4), the upper end of the middle threaded connecting pipe (6), the retaining ring cylinder (7), the lower end of the middle threaded connecting pipe (6) and the outer cylinder (8) are fixedly fitted in sequence. The lower connector (1) has a hollow structure inside and is fixedly connected to the inner cylinder (9) by a lower anti-reverse screw (2); The end threaded connecting pipe (3) has a hollow cylindrical structure. The end threaded connecting pipe (3) is fixedly sleeved on the outer wall of the inner cylinder (9). The inside of the end threaded connecting pipe (3) is full of threads. One end of the end threaded connecting pipe (3) is fixedly connected to the lower connector (1), and the other end of the end threaded connecting pipe (3) is fixedly connected to the pin cylinder (4). The pin cylinder (4) has a hollow cylindrical structure. Six pin holes are evenly distributed around the center of the pin cylinder (4). The pin cylinder (4) is fixedly connected to the inner cylinder (9) by a large shear pin (5). The central threaded connecting pipe (6) has a hollow cylindrical structure. The central threaded connecting pipe (6) is divided into an upper end and a lower end. The cylindrical body is covered with threads. The lower end of the central threaded connecting pipe (6) is fixedly connected to the pin cylinder (4). The lower end of the central threaded connecting pipe (6) is fixedly connected to the lower end of the central threaded connecting pipe (6) through the retaining ring cylinder (7). The outer cylinder (8) has two ends, namely the lower end of the outer cylinder (8) and the upper end of the outer cylinder (8). The lower end of the outer cylinder (8) is fixedly connected to the upper end of the middle threaded connecting pipe (6), and the upper end of the outer cylinder (8) is fixedly connected to the pressure balance pipe column (11) by the lower anti-reverse screw (2). A sealing limiting cylinder (10) has a hollow cylindrical structure. A limiting ring (20) is fitted on the outer wall of the sealing limiting cylinder (10) to limit the inner cylinder (9). The pressure balancing component includes: A chamber opening valve (21) is provided on the side wall of the pressure balancing tubing (11). The chamber opening valve (21) consists of an upper valve body (13), an upper plug (14), an upper shear pin (15), a chamber (22), a lower shear pin (17), and a lower plug (18). The lower plug (18) is first placed into the chamber opening valve (21) and fixed by the lower shear pin (17). Then the upper plug (14) is fixed above the lower plug (18) in the same way by the upper shear pin (15). When in use: When the external pressure of the oil pipe is greater than the internal pressure, the upper shear pin (15) of the pressure balance assembly is sheared, the upper plug (14) moves down, connecting the chamber (22) with the outside, increasing the volume of the external annulus, and reducing the annulus pressure; when the temperature rises and the oil pipe is subjected to excessive force, the large shear pin (5) installed on the pin cylinder (4) is sheared by the external force, the inner cylinder (9) is disconnected from the outer cylinder (8), the position of the outer cylinder (8) remains unchanged, and the inner cylinder (9) is stretched according to the oil pipe under force, reducing the oil pipe under force and avoiding oil pipe deformation; When the pressure inside the tubing is greater than the pressure outside the tubing, the lower shear pin (17) of the pressure balancing assembly is sheared, and the lower plug (18) moves upward, connecting the inside of the tubing to the chamber (22) and reducing the pressure inside the tubing. When the temperature drops and the force on the tubing becomes too great, the large shear pin (5) installed on the pin cylinder (4) is sheared by the external force, the inner cylinder (9) is disconnected from the outer cylinder (8), the position of the outer cylinder (8) remains unchanged, and the inner cylinder (9) shortens according to the force on the tubing, reducing the force on the tubing and avoiding damage to the tubing and failure of the packer.

2. The high-pressure oil and gas well closed annulus pressure control tool according to claim 1, characterized in that, The lower end of the inner cylinder (9) has symmetrical threaded holes that match the pin holes on the pin cylinder (4); the upper end of the inner cylinder (9) has threads, and the inner cylinder (9) is nested inside the outer cylinder (8).

3. The high-pressure oil and gas well closed annulus pressure control tool according to claim 1, characterized in that, The lower connector (1) is fixedly connected to the inner cylinder (9) by the lower anti-reverse screw (2).

4. The high-pressure oil and gas well closed annulus pressure control tool according to claim 1, characterized in that, The outer cylinder (8) has symmetrical threaded holes, which are matched with the symmetrical threaded holes on the pressure balance column (11) by the lower anti-reverse screw (2).

5. The high-pressure oil and gas well closed annulus pressure control tool according to claim 1, characterized in that, The upper plug (14), upper valve body (13) and pressure balance column (11) are interference fit and are limited by upper shear pin (15) and lower shear pin (17).

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