Special composite threaded oil pipe nipple with high-pressure leakage resistance and sealing structure thereof

Abstract

The present application relates to the technical field of oil pipe nipple, disclose a kind of special composite thread oil pipe nipple of high-pressure leakage resistance and sealing structure, wherein a kind of special composite thread oil pipe nipple of high-pressure leakage resistance, including connecting pipe body and two oil pipe interfaces, thread spiral groove being opened on the outer wall of two oil pipe interfaces, installation inner groove being opened in the two sides of oil pipe interface, matching groove being opened on the inner wall of installation inner groove, including the sealing unit being arranged in the inside of connecting pipe body, the sealing unit includes the trigger component and protection component being arranged in the inside of the two sides of connecting pipe body;By the process of installing connecting pipe body in oil pipe interface, movable resistance pressure rod drives inner pressure piston ring synchronous movement, when connecting pipe body is just completely threaded on oil pipe interface, gap between the two is completely blocked by blocking isolation sleeve, can effectively prevent the high pressure in the inside of connecting pipe body from directly acting on gap and exist leakage risk.

Description

Technical Field

[0001] This invention relates to the technical field of tubing short sections, and more particularly to a special composite threaded tubing short section resistant to high-pressure leakage and its sealing structure. Background Technology

[0002] Composite threaded tubing shorts are special tubing fittings adapted to oil and gas extraction scenarios. Their core feature is the optimization of key indicators such as sealing performance and connection strength through special threaded or composite structural designs. This solves problems such as permeation and wear of conventional tubing shorts in complex downhole environments. The function of composite threaded tubing shorts is to adapt to the connection requirements of oil and gas extraction tubing strings, while enhancing sealing, connection, and protection performance under complex operating conditions. As an adjustable component of the tubing string system, it can flexibly supplement or adjust the total length of the tubing string according to the actual downhole depth requirements, avoiding the adaptation problems caused by fixed standard tubing lengths, achieving reasonable transitions between tubing sections, and ensuring the overall continuity of the tubing string.

[0003] While existing threaded tubing short sections can improve the connection and protection performance of tubing, they still have the following problems: When the pressure of oil or natural gas inside the tubing suddenly increases to a high value, the resulting pressure will directly act on the connection gap between the tubing and the short section. The high-pressure medium will form a "permeation channel" along the threaded gap. The higher the pressure, the stronger the force of the medium to break through the seal. Moreover, when the high-pressure medium acts directly on the gap, the pressure value at the gap is the greatest due to the decomposition of forces. Therefore, by designing a sealing structure, the high pressure generated inside the tubing will not act directly on the gap, thus protecting the gap at the connection between the two and improving the high-pressure leakage resistance of the threaded tubing short section. Summary of the Invention

[0004] In view of the problem that existing technologies pose a risk of leakage when the pressure of the medium inside the oil pipe suddenly increases to a high value, the resulting high pressure acts directly on the gaps. Therefore, a special composite threaded oil pipe short section and its sealing structure that are resistant to high pressure leakage are proposed.

[0005] This application provides a special composite threaded oil pipe short section and its sealing structure for high-pressure leakage prevention. The purpose is as follows: during the installation of the connecting pipe body on the oil pipe interface, the oil pipe interface and the movable pressure rod come into contact and press against each other, generating a horizontal thrust on the movable pressure rod. This causes the movable pressure rod to drive the internal pressure piston ring to move synchronously. During the movement of the internal pressure piston ring, the sealing isolation sleeve moves synchronously. When the connecting pipe body is fully threaded onto the oil pipe interface, the sealing isolation sleeve completely blocks the gap between them, effectively preventing the high pressure inside the connecting pipe body from directly acting on the gap and causing leakage risk. Simultaneously, by setting protective components, the sealing isolation sleeve inflates and expands its internal sealing isolation ring during movement, sealing both sides of the sealing isolation sleeve and further protecting the gap.

[0006] The technical solution of the present invention is as follows: a special composite threaded oil pipe short section resistant to high pressure leakage, including a connecting pipe body and two oil pipe interfaces, threaded grooves opened on the outer walls of the two oil pipe interfaces, mounting inner grooves opened on both sides of the connecting pipe body, mating grooves opened on the inner walls of the mounting inner grooves, and a sealing unit disposed inside the connecting pipe body. The sealing unit includes a triggering component and a protective component disposed inside both sides of the connecting pipe body.

[0007] The triggering component includes an inner pressure piston ring slidably installed inside the mounting inner groove, a movable pressure rod disposed on the outer wall of the inner pressure piston ring, a reset spring disposed between the inner pressure piston ring and the inner wall of the mounting inner groove, an inner connecting groove opened inside the connecting pipe body, a movable ring slidably disposed inside the inner connecting groove, and a sealing isolation sleeve disposed on the inner wall of the movable ring.

[0008] The inner connecting groove is interconnected with the installation inner groove. The connecting pipe body is threadedly connected to the corresponding oil pipe interface through the mating grooves at both ends. When the connecting pipe body is threadedly installed at the oil pipe interface, the movable pressure rod is squeezed and moves in the horizontal direction. During the movement of the movable pressure rod, the moving ring moves synchronously by compressing the gas inside the installation inner groove. The sealing and isolation sleeve is used to shield and protect the gap between the connecting pipe body and the oil pipe interface.

[0009] Furthermore, the protective component includes a transformer chamber located inside the moving ring, a moving transformer plate slidably installed inside the transformer chamber, a moving trigger rod disposed on the outer wall of the moving transformer plate, a return spring disposed between the moving transformer plate and the inner wall of the transformer chamber, and a sealing assembly installed between the transformer chamber and the sealing isolation sleeve.

[0010] Furthermore, the sealing assembly includes sealing and insulating rings disposed on both sides of the sealing and insulating sleeve, and flow grooves formed on the inner wall of the sealing and insulating sleeve, the two ends of which are respectively connected to the transformer cavity and the interior of the sealing and insulating rings.

[0011] Furthermore, the sealing isolation ring is made of rubber material and is used to seal the space on both sides of the sealing isolation sleeve.

[0012] Furthermore, when the sealing isolation sleeve moves to the junction of the connecting pipe body and the oil pipe interface, the motion trigger rod will come into contact with the inside of the connecting pipe body. The motion transformer plate is used to compress the gas inside the transformer chamber, causing the sealing isolation ring to expand and seal both sides of the sealing isolation sleeve.

[0013] Furthermore, a sealing ring for improving sealing is fixedly sleeved on the outer wall of the internal pressure piston ring.

[0014] Furthermore, a sealing structure is applied to a special composite threaded tubing sub that is resistant to high-pressure leakage, comprising the following structures: a moving ring, a sealing isolation sleeve, and a sealing isolation ring.

[0015] The beneficial effects of this invention are:

[0016] By setting a trigger component, during the process of threading the connecting pipe body into the oil pipe interface, one end of the oil pipe interface comes into contact with and presses against the movable pressure rod, generating a horizontal thrust on the movable pressure rod and driving the internal pressure piston ring to move synchronously along the inner groove of the installation. By changing the internal air pressure, it drives the moving ring to move synchronously. When the connecting pipe body is fully threaded into the oil pipe interface, the sealing isolation sleeve completely blocks the gap between the connecting pipe body and the oil pipe interface, protecting the gap. When the pressure of the medium inside the oil pipe suddenly increases, the pressure generated cannot directly act on the gap, which can effectively reduce the occurrence of gap leakage caused by high pressure and improve the overall sealing performance and safety of the oil pipe section.

[0017] By incorporating protective components, as the moving ring moves horizontally, it drives the internal trigger rod to move synchronously. When the baffle blocks the gap, the trigger rod contacts and presses against the inside of the connecting pipe, causing the moving transformer plate to move synchronously inside the transformer chamber. This compresses the gas inside the transformer chamber into the sealing ring, causing the sealing ring to expand and fill and seal the gaps on both sides of the sealing sleeve, further protecting the gaps. This effectively prevents the pressure generated by the high-pressure medium from directly acting on the gaps and causing leakage risks.

[0018] By setting up a sealing isolation sleeve and a sealing isolation ring, even if the high-pressure medium breaks through the sealing isolation ring, the pressure it generates cannot directly act on the gap. When the existing short section is installed on the oil pipe, if high pressure is generated inside the oil pipe, the pressure will act directly on the gap in a vertical state. At this time, the pressure value at the gap is the greatest. However, by setting up a sealing isolation sleeve, the pressure cannot act directly vertically on the gap, but instead acts on the gap at a certain angle (in the case of high pressure breaking through the sealing isolation ring, the pressure generated by the high-pressure medium under normal circumstances cannot act above the gap). At this time, through force decomposition, it can be seen that the pressure on the gap will be greatly reduced, effectively improving the sealing effect and safety of the short section. Attached Figure Description

[0019] Figure 1 This is a first-view three-dimensional structural diagram of the present invention;

[0020] Figure 2 This is a schematic diagram of the connecting pipe installation structure of the present invention;

[0021] Figure 3 For the present invention Figure 2 Frontal view of the planar structure diagram;

[0022] Figure 4 This is a schematic diagram of the sealing unit structure of the present invention;

[0023] Figure 5 This is a schematic diagram of the internal structure of the connecting tube of the present invention;

[0024] Figure 6 This is a schematic diagram of the sealing and insulating sleeve installation structure of the present invention;

[0025] Figure 7 For the present invention Figure 5 Enlarged view of point A in the middle;

[0026] Figure 8 For the present invention Figure 5 Enlarged diagram of point B in the middle.

[0027] In the picture:

[0028] 1. Connecting pipe body; 2. Oil pipe interface; 3. Threaded groove; 4. Installation inner groove; 101. Internal pressure piston ring; 102. Movable pressure bar; 103. Return spring; 104. Internal connecting groove; 105. Moving ring; 106. Sealing isolation sleeve; 201. Transformer chamber; 202. Moving transformer plate; 203. Moving trigger rod; 204. Return spring; 301. Sealing isolation ring; 302. Flow groove. Detailed Implementation

[0029] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0030] Example 1, referring to Figures 1-7 The first embodiment of the present invention provides a special composite threaded oil pipe short section resistant to high pressure leakage, including a connecting pipe body 1 and two oil pipe interfaces 2, threaded grooves 3 formed on the outer walls of the two oil pipe interfaces 2, mounting inner grooves 4 formed on both sides of the connecting pipe body 1, mating grooves formed on the inner walls of the mounting inner grooves 4, and a sealing unit installed inside the connecting pipe body 1. The sealing unit includes a triggering component and a protective component installed inside both sides of the connecting pipe body 1.

[0031] The triggering components include an inner pressure piston ring 101 slidably installed inside the mounting inner groove 4, a movable pressure rod 102 fixedly installed on the outer wall of the inner pressure piston ring 101, a return spring 103 fixedly installed between the inner pressure piston ring 101 and the inner wall of the mounting inner groove 4, an inner connecting groove 104 opened inside the connecting pipe body 1, a movable ring 105 slidably installed inside the inner connecting groove 104, and a sealing isolation sleeve 106 fixedly installed on the inner wall of the movable ring 105.

[0032] The inner connecting groove 104 is connected to the installation inner groove 4. The connecting pipe 1 is threadedly connected to the corresponding oil pipe interface 2 through the mating grooves at both ends. When the connecting pipe 1 is threadedly installed at the oil pipe interface 2, the movable pressure rod 102 is squeezed and moves in the horizontal direction. During the movement of the movable pressure rod 102, the gas inside the installation inner groove 4 is compressed, which drives the moving ring 105 to move synchronously. The sealing isolation sleeve 106 is used to shield and protect the gap between the connecting pipe 1 and the oil pipe interface 2.

[0033] Specifically, the working principle of the triggering component is as follows: by setting a sealing isolation sleeve 106, when the connecting pipe body 1 is threadedly connected to the corresponding oil pipe interface 2, the sealing isolation sleeve 106 can automatically slide to the junction gap between the two, isolating the gap from the medium inside the oil pipe, thereby preventing the risk of leakage through the gap when the pressure inside the oil pipe increases. By setting the sealing isolation sleeve 106, when the pressure inside the oil pipe increases, the pressure generated acts directly on the outer wall of the sealing isolation sleeve 106 rather than the gap, thereby ensuring the overall sealing and safety of the connecting pipe body 1.

[0034] Both ends of the connecting pipe body 1 are equipped with sealing units. The connecting pipe body 1 is threaded onto the oil pipe interface 2 through the mutual cooperation of the mating groove inside the mounting groove and the threaded groove 3 at the oil pipe interface 2. When the operator needs to install the connecting pipe body 1 onto the oil pipe interface 2, one end of the oil pipe interface 2 is aligned with the inside of the mounting groove 4 and rotated so that the thread of the connecting pipe body 1 is installed inside the oil pipe interface 2. During the installation process, one end of the oil pipe interface 2 comes into contact with and presses against the movable pressure rod 102, causing the movable pressure rod 102 to move horizontally under pressure. During the compression and movement process, the internal pressure piston ring 101 at one end slides on the inner wall of the mounting inner groove 4. By changing the air pressure inside the mounting inner groove 4, the moving ring 105 slides in the opposite direction inside the inner connecting groove 104. During the movement of the moving ring 105, the sealing isolation sleeve 106 on the inner wall moves synchronously. The sealing isolation sleeve 106 is located on the inner wall of the connecting pipe body 1. Therefore, when the connecting pipe body 1 is installed on the oil pipe interface 2, the sealing isolation sleeve 106 moves synchronously to the gap between the two, thereby protecting the gap area and improving the overall stability and sealing performance.

[0035] During use, when the connecting pipe body 1 needs to be installed between two oil pipe interfaces 2, the operator aligns the inner groove 4 at one end of the connecting pipe body 1 with the corresponding end of the oil pipe interface 2, and rotates the connecting pipe body 1 so that the mating groove inside the connecting pipe body 1 engages with the threaded groove 3 on the outer wall of the oil pipe interface 2, allowing the connecting pipe body 1 to be threaded onto the oil pipe interface 2. During the installation of the connecting pipe body 1, one end of the oil pipe interface 2 comes into contact with the movable pressure rod 102 and is squeezed. The movable pressure rod 102 generates a horizontal thrust during the squeezing process, and the movable pressure rod 102 drives the inner pressure piston ring 10 during the thrust. 1. Moving synchronously along the horizontal direction, the internal pressure piston ring 101 changes the air pressure inside the mounting inner groove 4 during its movement. The pressure generated by the air pressure acts directly on the moving ring 105 through the inner connecting groove 104, causing the moving ring 105 to slide inside the inner connecting groove 104. The moving ring 105 moves in the opposite direction to the movable pressure rod 102, and drives the sealing isolation sleeve 106 on the inner wall to slide synchronously. When the connecting pipe body 1 is fully threaded onto the oil pipe interface 2, the sealing isolation sleeve 106 moves to its maximum position. At this time, the sealing isolation sleeve 106 seals and protects the gap between the connecting pipe body 1 and the oil pipe interface 2.

[0036] Example 2, refer to Figures 1-6 as well as Figure 8 This is the second embodiment of the present invention, which differs from the first embodiment in that: the protective component includes a transformer chamber 201 formed inside the moving ring 105, a moving transformer plate 202 slidably installed inside the transformer chamber 201, a moving trigger rod 203 fixedly installed on the outer wall of the moving transformer plate 202, a return spring 204 fixedly installed between the moving transformer plate 202 and the inner wall of the transformer chamber 201, and a sealing assembly installed between the transformer chamber 201 and the sealing isolation sleeve 106. The sealing assembly includes sealing isolation rings 301 fixedly installed on the outer walls of both sides of the sealing isolation sleeve 106, and flow grooves 302 formed on the inner wall of the sealing isolation sleeve 106, with both ends of the flow grooves 302 communicating with the transformer chamber 201 and the interior of the sealing isolation rings 301, respectively. The sealing isolation rings 301 are made of rubber material and are used to seal the space on both sides of the sealing isolation sleeve 106. When the sealing isolation sleeve 106 moves to the junction of the connecting pipe body 1 and the oil pipe interface 2, the motion trigger rod 203 will then come into contact with the inside of the connecting pipe body 1. The motion transformer plate 202 is used to compress the gas inside the transformer chamber 201, causing the sealing isolation ring 301 to expand and seal both sides of the sealing isolation sleeve 106. A sealing ring for improving sealing performance is fixedly sleeved on the outer wall of the internal pressure piston ring 101.

[0037] Specifically, the protective component is used to assist the triggering component in protecting the gap. Because the sealing isolation sleeve 106 slides on the inner wall of the connecting pipe body 1, there is a gap between the sealing isolation sleeve 106 and the connecting pipe body 1. In order to prevent the internal high-pressure oil from flowing into the gap through the gap, the protective component is set to fill and seal the gap between the sealing isolation sleeve 106 and the connecting pipe body 1. When the sealing isolation sleeve 106 moves to the gap between the connecting pipe body 1 and the oil pipe interface 2, the moving trigger rod 203 contacts the inner wall of the connecting pipe body 1. At this time, the moving trigger rod 203 is in contact with the inner wall of the connecting pipe body 1 and is pushed. When the moving ring 105 continues to move, the moving trigger rod 203 drives the moving transformer plate 202 to move relative to each other and compresses the gas inside the transformer chamber 201 into the sealing isolation ring 301, causing the sealing isolation ring 301 to expand and fill the gap between the sealing isolation sleeve 106 and the inner wall of the connecting pipe body 1.

[0038] By sealing the gap between the sealing isolation sleeve 106 and the connecting pipe body 1, it can effectively prevent the pressure generated by the high-pressure oil inside from acting directly on the gap between the connecting pipe body 1 and the oil pipe interface 2, thus protecting it. Even if the oil pressure is too high and the sealing isolation ring 301 is activated, the pressure of the high-pressure oil will not act directly perpendicularly on the gap, but will act on the gap at a certain angle. At this time, the pressure on the gap is greatly reduced, which can effectively improve the sealing performance when dealing with high pressure.

[0039] During use, when the moving ring 105 moves, it drives the sealing sleeve 106 on the inner wall to move synchronously. After the sealing sleeve 106 moves to the gap between the two, the moving trigger rod 203 comes into contact with and squeezes the inner wall of the connecting pipe 1. When the sealing sleeve 106 moves downward horizontally again, the moving trigger rod 203 is squeezed by the inner wall and no longer moves synchronously. Instead, it drives the moving transformer plate 202 at one end to move in the opposite direction. During the movement of the moving transformer plate 202, it squeezes the air inside the transformer chamber 201 and squeezes the air inside through the flow groove 302 into the sealing ring 301. After the air enters the sealing ring 301, it expands. During the expansion process, it fills the gap between the sealing sleeve 106 and the inner wall of the connecting pipe 1, and further fills and protects the gap between the connecting pipe 1 and the oil pipe interface 2.

[0040] The remaining structure is the same as that in Example 1.

[0041] Example 3, referring to Figures 1-8 Furthermore, it improves upon the following: a sealing structure comprising the following components: a moving ring 105, a sealing isolation sleeve 106, and a sealing isolation ring 301.

[0042] The remaining structure is the same as that in Example 2.

[0043] Based on embodiments 1-3, the working principle of the present invention is as follows: When the connecting pipe body 1 needs to be installed between two oil pipe interfaces 2, the operator aligns the inner groove 4 at one end of the connecting pipe body 1 with the corresponding end of the oil pipe interface 2, and rotates the connecting pipe body 1 so that the mating groove inside the connecting pipe body 1 and the threaded groove 3 on the outer wall of the oil pipe interface 2 cooperate with each other, so that the connecting pipe body 1 is threadedly installed on the oil pipe interface 2. During the installation of the connecting pipe body 1, one end of the oil pipe interface 2 comes into contact with the movable pressure rod 102 and generates compression. During the compression process, the movable pressure rod 102 generates a horizontal thrust. During the thrust process, the movable pressure rod 102 drives the inner pressure piston ring 101 to move synchronously in the horizontal direction.

[0044] During the movement of the internal pressure piston ring 101, the air pressure inside the mounting inner groove 4 is changed. The pressure generated by the air pressure acts directly on the moving ring 105 through the inner connecting groove 104, causing the moving ring 105 to slide inside the inner connecting groove 104. The moving ring 105 moves in the opposite direction to the movable pressure rod 102, and drives the sealing isolation sleeve 106 on the inner wall to slide synchronously. When the connecting pipe body 1 is fully threaded on the oil pipe interface 2, the sealing isolation sleeve 106 moves to the maximum position. At this time, the sealing isolation sleeve 106 seals and protects the gap between the connecting pipe body 1 and the oil pipe interface 2.

[0045] When the moving ring 105 moves, it drives the sealing sleeve 106 on the inner wall to move synchronously. After the sealing sleeve 106 moves to the gap between the two, the moving trigger rod 203 comes into contact with and squeezes the inner wall of the connecting pipe 1. When the sealing sleeve 106 moves downward horizontally again, the moving trigger rod 203 is squeezed by the inner wall and no longer moves synchronously. Instead, it drives the moving transformer plate 202 at one end to move in the opposite direction. During the movement of the moving transformer plate 202, it squeezes the air inside the transformer cavity 201 and squeezes the air inside the cavity into the sealing ring 301 through the flow groove 302. After the air enters the sealing ring 301, it expands. During the expansion process, it fills the gap between the sealing sleeve 106 and the inner wall of the connecting pipe 1, and further fills and protects the gap between the connecting pipe 1 and the oil pipe interface 2.

[0046] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A special composite threaded oil pipe short section resistant to high pressure leakage, comprising a connecting pipe body (1) and two oil pipe interfaces (2), threaded grooves (3) formed on the outer walls of the two oil pipe interfaces (2), mounting inner grooves (4) formed on both sides of the connecting pipe body (1), and mating grooves formed on the inner walls of the mounting inner grooves (4), characterized in that, It includes a sealing unit disposed inside the connecting tube body (1), the sealing unit including a triggering component and a protective component disposed inside both sides of the connecting tube body (1); The triggering component includes an inner pressure piston ring (101) slidably installed inside the mounting inner groove (4), a movable pressure rod (102) disposed on the outer wall of the inner pressure piston ring (101), a reset spring (103) disposed between the inner pressure piston ring (101) and the inner wall of the mounting inner groove (4), an inner connecting groove (104) opened inside the connecting pipe (1), a movable ring (105) slidably disposed inside the inner connecting groove (104), and a sealing isolation sleeve (106) disposed on the inner wall of the movable ring (105). The inner connecting groove (104) is connected to the installation inner groove (4). The connecting pipe (1) is threadedly connected to the corresponding oil pipe interface (2) through the mating grooves at both ends. When the connecting pipe (1) is threadedly installed at the oil pipe interface (2), the movable pressure rod (102) is squeezed and moves in the horizontal direction. During the movement of the movable pressure rod (102), the moving ring (105) is driven to move synchronously by compressing the gas inside the installation inner groove (4). The sealing isolation sleeve (106) is used to shield and protect the gap between the connecting pipe (1) and the oil pipe interface (2).

2. The special composite threaded oil pipe short section for high-pressure leakage resistance according to claim 1, characterized in that, The protective component includes a transformer chamber (201) opened inside the moving ring (105), a moving transformer plate (202) slidably installed inside the transformer chamber (201), a moving trigger rod (203) set on the outer wall of the moving transformer plate (202), a return spring (204) set between the moving transformer plate (202) and the inner wall of the transformer chamber (201), and a sealing component installed between the transformer chamber (201) and the sealing isolation sleeve (106).

3. The special composite threaded oil pipe short section for high-pressure leakage resistance according to claim 2, characterized in that, The sealing assembly includes sealing isolation rings (301) disposed on both sides of the sealing isolation sleeve (106) and flow grooves (302) formed on the inner wall of the sealing isolation sleeve (106). The two ends of the flow grooves (302) are respectively connected to the transformer cavity (201) and the interior of the sealing isolation rings (301).

4. The special composite threaded oil pipe short section for high-pressure leakage resistance according to claim 3, characterized in that, The sealing isolation ring (301) is made of rubber material and is used to seal the space on both sides of the sealing isolation sleeve (106).

5. The special composite threaded oil pipe short section for high-pressure leakage resistance according to claim 4, characterized in that, When the sealing isolation sleeve (106) moves to the junction of the connecting pipe body (1) and the oil pipe interface (2), the motion trigger rod (203) will come into contact with the inside of the connecting pipe body (1). The motion transformer plate (202) is used to compress the gas inside the transformer chamber (201), so that the sealing isolation ring (301) expands to seal both sides of the sealing isolation sleeve (106).

6. The special composite threaded oil pipe short section resistant to high-pressure leakage according to claim 1, characterized in that, A sealing ring for improving sealing is fixedly sleeved on the outer wall of the internal pressure piston ring (101).

7. A sealing structure applied to a special composite threaded oil pipe sub section for high-pressure leakage resistance as described in claim 6, characterized in that, It includes the following structures: a moving ring (105), a sealing isolation sleeve (106), and a sealing isolation ring (301).

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