A downhole dual-channel check valve

Abstract

The present invention relates to the technical field of downhole tools for petroleum production. The present invention discloses a downhole dual-channel check valve, comprising a valve body, a first threaded hole and a second threaded hole being arranged opposite each other on the valve body, an inner liquid inlet channel and an outer liquid return channel being respectively located within the valve body and connected between the first threaded hole and the second threaded hole, six outer liquid return channels being arranged in a circular array with the inner liquid inlet channel as the center, and further comprising: a central rotating block located within the valve body, six liquid return holes being arranged in a circular array on the central rotating block and connected to the outer liquid return channels, a valve core assembly being provided within the central rotating block, a drive assembly adapted for the valve core assembly and the central rotating block being installed near both ends of the inner liquid inlet channel near the threaded holes, when the drive assembly is reset, the valve core assembly blocks the inner liquid inlet channel near one end of the threaded holes, and the liquid return hole and the outer liquid return channel are staggered, thereby blocking the outer liquid return channel. The downhole dual-channel check valve disclosed by the present invention has a relatively simple mechanical structure, and the travel of the outer liquid return channel having a liquid return function is relatively short, thereby simplifying the structure of the valve control assembly.

Description

Technical Field

[0001] The present invention relates to the technical field of downhole petroleum production tools, in particular to a downhole dual-channel check valve. Background Art

[0002] When double-layer coiled tubing is used with tools, unexpected accidents may cause damage or breakage of the double-layer coiled tubing. At this time, oil, gas and water in the well will gush out from the inner and outer channels of the double-layer coiled tubing after the break, causing a blowout accident.

[0003] Chinese patent document CN11878033A discloses a downhole dual-channel check valve, which is disposed between two layers of coiled tubing and communicates with the bottom hole at its right end. The valve body comprises a valve body, wherein a first left threaded hole and a second left threaded hole are provided at the left end of the valve body. A second left through hole communicates with the first left threaded hole and a first left through hole communicates with the second left threaded hole are provided within the valve body. A first right threaded hole connected to the outer coiled tubing is provided at the right end of the valve body. A valve hole extending leftward is provided within the valve body at the center of the left end of the first right threaded hole. A screw plug is fixedly mounted at the right end opening of the valve hole. A second right threaded hole connected to the inner coiled tubing is provided within the screw plug. A second right through hole communicates with the first right threaded hole is provided within the valve body. A valve control assembly is provided within the valve hole. The check valve can effectively seal the passages between the inner and outer coiled tubing in the event of an accident, thereby preventing well fluid from flowing back out and preventing a blowout. However, the design of the valve core, multiple springs, multiple oil holes, through holes and ring grooves makes the mechanical structure of the valve control assembly relatively complex. How to reduce the number of springs and reduce the through hole stroke to simplify the mechanical structure of the valve control assembly is an urgent problem to be solved. Summary of the Invention

[0004] To achieve the above-mentioned objectives, the present invention discloses a downhole dual-channel one-way valve, comprising a valve body, on which threaded hole one and threaded hole two are arranged opposite to each other, an inner liquid inlet channel and an outer liquid return channel are respectively located in the valve body and are connected between threaded hole one and threaded hole two, and six outer liquid return channels are distributed in a circular array with the inner liquid inlet channel as the center, and further comprising: a central rotating block located in the valve body, six liquid return holes connected to the outer liquid return channels are distributed in a circular array on the central rotating block, a valve core assembly is penetrated by the central rotating block, and a driving assembly adapted to the valve core assembly and the central rotating block is installed near the two ends of the inner liquid inlet channel near the threaded holes. When the driving assembly is reset, the valve core assembly blocks the inner liquid inlet channel near one end of the threaded hole, and at the same time, the liquid return hole and the outer liquid return channel are staggered, and the outer liquid return channel is blocked.

[0005] Preferably, the valve body is composed of a detachable left valve body and a right valve body, threaded hole one is located on the left valve body, threaded hole two is located on the right valve body, and an installation chamber for installing the center rotating block is provided at one end of the left valve body away from the threaded hole.

[0006] Preferably, a sealing ring adapted to be connected to the central rotating block is installed on the inner wall of the installation chamber.

[0007] Preferably, the valve core assembly includes a rod-shaped valve core, the valve core is semi-spherical at one end near the threaded hole, the inner wall of the internal liquid inlet channel near the threaded hole is closed at one end near the threaded hole to adapt to the sealing of the valve core near the threaded hole, the two ends of the valve core near the threaded hole are hollow, a sealing ring seat is provided on the valve core, the sealing ring seat is rotatably connected to the inner wall of the internal liquid inlet channel to seal the installation chamber, the center rotating block is installed on the sealing ring seat, the side end of the valve core is provided with a liquid inlet connected thereto, and the inner ring end of the sealing ring seat is circularly arrayed with limit slots, the limit strips are inserted in the limit slots and are fixedly connected to the valve core.

[0008] Preferably, the drive assembly comprises:

[0009] The screw plug is installed at the two ends of the inner liquid inlet channel near the threaded hole, and an internal threaded hole communicating with the inner liquid inlet channel is opened in the screw plug;

[0010] Internal ferrule, which is fixed on the screw plug and connected to the internal threaded hole;

[0011] The slide plate is slidably mounted on the inner wall of the inner liquid inlet channel. The center end of the slide plate is integrally formed with an inner groove. The bottom end of the inner groove is protruding toward the screw plug. The outer ferrule is mounted on the bottom end of the inner groove. The outer ferrule is sleeved on the inner ferrule. The return spring is sleeved on the outer ferrule and is positioned between the bottom end of the inner groove and the screw plug.

[0012] The central liquid inlet pipe is fixedly installed at the central end of the inner groove, passes through the outer ferrule, and extends into the inner ferrule.

[0013] Preferably, the drive assembly further comprises:

[0014] Wedge-shaped top blocks, wherein four wedge-shaped top blocks are distributed in a circular array in the inner groove with the central liquid inlet pipe as the center, and adjacent first and second inclined surfaces are provided on the wedge-shaped top blocks;

[0015] Wedge-shaped push rod one, wedge-shaped push rod two, four wedge-shaped push rods one are installed in a circular array on the two ends of the valve core near the threaded hole, wedge-shaped push rod one is bent at an obtuse angle near the end of the valve core, wedge-shaped push rod one extends into the inner groove away from the valve core and is adapted to the first inclined surface setting, wedge-shaped push rod one is slidingly connected to the central liquid inlet pipe away from the end of the valve core, four wedge-shaped push rods two are installed in a circular array on the two ends of the sealing ring seat near the threaded hole, wedge-shaped push rod two extends into the inner groove away from the sealing ring seat and is adapted to the second inclined surface setting.

[0016] Preferably, the slope of the first inclined surface is smaller than that of the second inclined surface.

[0017] Preferably, multiple groups of guide sleeve rods are connected between the slide plate and the screw plug. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 The structure of the present invention is schematically shown Figure 1 (When the internal liquid inlet channel and the external liquid return channel are blocked);

[0020] Figure 2 The structure of the present invention is schematically shown Figure 2 (When the inner liquid inlet channel and the outer liquid return channel are in circulation);

[0021] Figure 3 This is a schematic diagram of the valve body structure of the present invention;

[0022] Figure 4 It is a cross-sectional view of the drive assembly, valve core assembly and central rotating block of the present invention in a mating state;

[0023] Figure 5 This is an appearance diagram of the drive assembly, valve core assembly and center rotating block of the present invention in a mating state;

[0024] Figure 6 This is a schematic diagram of the cooperation between the central rotating block and the valve core assembly of the present invention;

[0025] Figure 7 This is a schematic diagram of the wedge-shaped top block of the present invention being installed in the inner groove.

[0026] In the figure: 1. Valve body; 2. Threaded hole 1; 3. Threaded hole 2; 4. Internal liquid inlet channel; 5. External liquid return channel; 6. Center rotating block; 7. Liquid return hole; 8. Valve core assembly; 9. Drive assembly; 10. Left valve body; 11. Right valve body; 12. Sealing ring; 13. Valve core; 14. Sealing ring seat; 15. Liquid inlet; 16. Limiting strip; 17. Screw plug; 18. Internal threaded hole; 19. Internal ferrule; 20. Slide plate; 21. Internal groove; 22. External ferrule; 23. Return spring; 24. Center liquid inlet pipe; 25. Wedge-shaped top block; 251. First inclined surface; 252. Second inclined surface; 26. Wedge-shaped top rod 1; 27. Wedge-shaped top rod 2; 28. Guide sleeve; 29. ​​Installation chamber. DETAILED DESCRIPTION

[0027] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0028] Example

[0029] The present invention will be further described below with reference to the accompanying drawings.

[0030] like Figures 1 to 7 As shown, the present embodiment provides a downhole dual-channel one-flow valve, including a valve body 1, on which threaded hole 1 2 and threaded hole 2 3 are arranged opposite to each other, an inner liquid inlet channel 4 and an outer liquid return channel 5 are respectively located in the valve body 1 and connected between threaded hole 1 2 and threaded hole 2 3, and six outer liquid return channels 5 are distributed in a circular array with the inner liquid inlet channel 4 as the center, and also include: a central rotating block 6 located in the valve body 1, six liquid return holes 7 connected to the outer liquid return channel 5 are distributed in a circular array on the central rotating block 6, a valve core assembly 8 is penetrated by the central rotating block 6, and a driving assembly 9 adapted to the valve core assembly 8 and the central rotating block 6 is installed near the end of the inner liquid inlet channel 4 near the threaded hole 2 3. When the driving assembly 9 is reset, the valve core assembly 8 blocks the inner liquid inlet channel 4 near the end of the threaded hole 1 2, and at the same time, the liquid return hole 7 is staggered with the outer liquid return channel 5, and the outer liquid return channel 5 is blocked.

[0031] The working principle and beneficial effects of the above technical solution are:

[0032] The present invention provides a downhole dual-channel check valve. An internal fluid inlet channel 4 receives fluid from a valve body 1, while an external fluid return channel 5 returns fluid from the valve body 1. A valve core assembly 8 is used to block the internal fluid inlet channel 4, and a central pivot block 6 is used to block the external fluid return channel 5. Under normal conditions, well wash fluid is fed into the internal fluid inlet channel 4 of the valve body 1 through threaded hole 1 (2). The pressure near threaded hole 1 (2) on the valve body 1 is greater than the pressure near threaded hole 2 (3). At this point, the valve core assembly 8 releases its blockage of the internal fluid inlet channel 4. The valve core assembly 8 acts on the drive assembly 9 and actively rotates the central pivot block 6, connecting the fluid return hole 7 with the external fluid return channel 5. The central pivot block 6 releases its blockage of the external fluid return channel 5. In the event of an emergency, when bottomhole pressure is excessively high, the valve core assembly 8, under high pressure, quickly resets and blocks the internal fluid inlet channel 4. The drive assembly 9 resets and acts in the opposite direction on the central pivot block 6, causing the fluid return hole 7 to shift with the external fluid return channel 5, thus blocking the external fluid return channel 5. The downhole dual-channel check valve disclosed in the present invention has a relatively simple mechanical structure, and the stroke of the external liquid return channel 5 with liquid return function is relatively short, thereby simplifying the structure of the valve control component.

[0033] In one embodiment, the valve body 1 is composed of a detachable left valve body 10 and a right valve body 11, the threaded hole 12 is located on the left valve body 10, the threaded hole 2 is located on the right valve body 11, and an installation chamber 29 for installing the center rotating block 6 is provided at the end of the left valve body 10 away from the threaded hole 12.

[0034] The working principle and beneficial effects of the above technical solution are:

[0035] The valve body 1 is composed of a detachable left valve body 10 and a right valve body 11, which is easy to disassemble and assemble the entire structure. The setting of the installation chamber 29 facilitates the installation and rotation of the central rotating block 6.

[0036] In one embodiment, a sealing ring 12 adapted to be connected to the central rotating block 6 is installed on the inner wall of the installation chamber 29 .

[0037] The beneficial effects of the above technical solution are:

[0038] The provision of the sealing ring 12 facilitates the sealing of the central rotating block 6 in the installation chamber 29 , thereby ensuring the independent flow of the inner liquid inlet channel 4 and the outer liquid return channel 5 .

[0039] In one embodiment, the valve core assembly 8 includes a rod-shaped valve core 13, the valve core 13 is hemispherically arranged near the end of the threaded hole 12, and the inner wall of the internal liquid inlet channel 4 near the end of the threaded hole 12 is closed near the end of the threaded hole 12 to adapt to the sealing of the valve core 13 near the end of the threaded hole 12. The valve core 13 is hollow near the end of the threaded hole 23. A sealing ring seat 14 is provided on the valve core 13, and the sealing ring seat 14 is rotatably connected to the inner wall of the internal liquid inlet channel 4 to seal the installation chamber 29. The central rotating block 6 is installed on the sealing ring seat 14. A liquid inlet 15 connected to it is opened at the side end of the valve core 13, and a limiting card groove is distributed in a circular array on the inner ring end of the sealing ring seat 14. The limiting card strip 16 is inserted in the limiting card groove and fixedly connected to the valve core 13.

[0040] The working principle and beneficial effects of the above technical solution are:

[0041] The valve core 13 is arranged in a hemispherical shape near the end of the threaded hole 2. When liquid is supplied from the threaded hole 2 to the inner liquid inlet channel 4, the valve core 13 is pushed open, and the valve core 13 releases the blockage of the inner liquid inlet channel 4. The well washing fluid is supplied from the liquid inlet port 15 into the inner liquid inlet channel 4 of the valve core 13. When the valve core 13 moves in the direction away from the threaded hole 2, it acts on the drive assembly 9, and the valve core 13 itself drives the sealing ring seat 14 and the center rotating block 6 connected to the sealing ring seat 14 to rotate through the cooperation of the limit card strip 16 and the limit card groove. The return liquid hole 7 is connected with the external return liquid channel 5, and the center rotating block 6 releases the blockage of the external return liquid channel 5, thereby realizing the return of oil in the external return liquid channel 5. When the bottom hole pressure is too high, the valve core 13 is quickly reset under high pressure and blocks the inner liquid inlet channel 4, and the drive assembly 9 is reset and acts in the reverse direction on the sealing ring seat 14 and the central rotating block 6 connected to the sealing ring seat 14, thereby causing the central rotating block 6 to rotate in the reverse direction, and the return liquid hole 7 is staggered with the external return liquid channel 5, and the external return liquid channel 5 is blocked.

[0042] In one embodiment, the drive assembly 9 comprises:

[0043] The screw plug 17 is installed in the inner liquid inlet channel 4 near the second and third ends of the threaded holes. The screw plug 17 is provided with an internal threaded hole 18 that communicates with the inner liquid inlet channel 4.

[0044] Internal ferrule 19, which is fixedly mounted on screw plug 17 and communicated with internal threaded hole 18;

[0045] The slide plate 20 is slidably mounted on the inner wall of the inner liquid inlet channel 4. The center end of the slide plate 20 is integrally formed with an inner groove 21. The bottom end of the inner groove 21 protrudes toward the screw plug 17. The outer ferrule 22 is mounted on the bottom end of the inner groove 21. The outer ferrule 22 is sleeved on the inner ferrule 19. The return spring 23 is sleeved on the outer ferrule 22 and is disposed between the bottom end of the inner groove 21 and the screw plug 17.

[0046] The central liquid inlet pipe 24 is fixedly installed at the central end of the inner groove 21, and the central liquid inlet pipe 24 passes through the outer ferrule 22 and extends into the inner ferrule 19;

[0047] The drive assembly 9 also includes:

[0048] Wedge-shaped top blocks 25, four wedge-shaped top blocks 25 are distributed in a circular array in the inner groove 21 with the central liquid inlet pipe 24 as the center, and the wedge-shaped top blocks 25 are adjacently provided with a first inclined surface 251 and a second inclined surface 252;

[0049] Wedge-shaped push rod 1 26 and wedge-shaped push rod 27, four wedge-shaped push rods 1 26 are integrally installed in a circular array on the valve core 13 near the end of threaded hole 23, the wedge-shaped push rod 1 26 is bent at an obtuse angle near the end of the valve core 13, the wedge-shaped push rod 1 26 extends into the inner groove 21 away from the end of the valve core 13, and is adapted to the first inclined surface 251. The wedge-shaped push rod 1 26 is slidably connected to the central liquid inlet pipe 24 away from the end of the valve core 13, and the four wedge-shaped push rods 27 are installed in a circular array on the sealing ring seat 14 near the end of threaded hole 23, the wedge-shaped push rod 27 extends into the inner groove 21 away from the end of the sealing ring seat 14, and is adapted to the second inclined surface 252.

[0050] The root of the wedge-shaped top block 25 is flat at a position close to the first inclined surface 251 and the second inclined surface 252 , and the root of the wedge-shaped top block 25 is close to the bottom of the inner groove 21 .

[0051] The working principle and beneficial effects of the above technical solution are:

[0052] When liquid is fed from threaded hole 12 to the inner liquid inlet channel 4, the valve core 13 is pushed open, the valve core 13 releases the blockage of the inner liquid inlet channel 4, and the well washing fluid is fed into the valve core 13 from the liquid inlet port 15 and out from the central liquid inlet pipe 24, the inner ferrule 19, the inner threaded hole 18 and the threaded hole 23. The return spring 23 contracts, and the outer ferrule 22 connected to the inner groove 21 slides on the inner ferrule 19. The wedge-shaped push rod 1 26 connected to the valve core 13 extends into the inner groove 21 and gradually rests on the first inclined surface 251. Because the wedge-shaped push rod 27 has not separated from the root of the wedge-shaped push block 25 at this time, the sealing ring seat 14 connected to the wedge-shaped push rod 27 does not move, and the valve core 13 located in the sealing ring seat 14 cannot rotate. Then, wedge-shaped push rod 1 26 abuts against first inclined surface 251, only able to drive inner groove 21 and slide plate 20 connected thereto toward the contraction direction of return spring 23. As wedge-shaped push rod 27 disengages from the base of wedge-shaped push block 25, wedge-shaped push rod 1 26 abuts against first inclined surface 251, driving valve core 13 connected thereto, sealing ring seat 14 sleeved thereon, and center rotating block 6 connected thereto to rotate within mounting chamber 29. Wedge-shaped push rod 27 rotates toward second inclined surface 252, connecting liquid return hole 7 with external liquid return channel 5. External liquid return channel 5 enters a flowing state, and liquid return is returned from external liquid return channel 5 and liquid return hole 7 to threaded hole 1 2. As wedge-shaped push rod 1 26 slides along first inclined surface 251 to near the base of wedge-shaped push block 25, valve core 13 stops rotating. In this state, both the inner liquid inlet channel 4 and the outer liquid return channel 5 are in a flow state.

[0053] In the event of an emergency, when the bottom hole pressure is too high, the valve core 13 is quickly reset and blocks the inner liquid inlet channel 4 under high pressure. After the wedge-shaped top block 25 loses the limit of the wedge-shaped top rod 1 26, under the reset of the reset spring 23, the inner groove 21 and the slide plate 20 connected to the inner groove 21 move in the extension direction of the reset spring 23, and the second inclined surface 252 quickly presses against the wedge-shaped top rod 27, so that the sealing ring seat 14 connected to the wedge-shaped top rod 27 and the sealing ring seat 14 connected to the sealing ring seat 14 are The central rotating block 6 connected to the valve stem 14 rotates in the opposite direction within the installation chamber 29. The wedge-shaped push rod 27 is located at the root of the wedge-shaped push rod 25. The return hole 7 is staggered with the external return channel 5, and the external return channel 5 is blocked. After the valve core 13 is blocked on the internal liquid inlet channel 4, the sealing ring seat 14 drives it to rotate in the opposite direction. The valve core 13 rotates on the inner wall of the internal liquid inlet channel 4, thereby crushing the debris ejected from the bottom of the well, ensuring that the valve core 13 completely blocks the internal liquid inlet channel 4. In this state, both the internal liquid inlet channel 4 and the external return channel 5 are in a blocked state.

[0054] By providing a single spring, the return spring 23 , the structure of the valve control assembly is simplified.

[0055] In one embodiment, the slope of the first inclined surface 251 is smaller than that of the second inclined surface 252 .

[0056] In one embodiment, multiple groups of guide sleeve rods 28 are connected between the slide plate 20 and the screw plug 17 .

[0057] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A downhole dual-channel check valve, comprising a valve body (1), wherein a first threaded hole (2) and a second threaded hole (3) are provided on the valve body (1) in opposite directions, and characterized in that: The inner liquid inlet channel (4) and the outer liquid return channel (5) are respectively located in the valve body (1) and are connected between the threaded hole 1 (2) and the threaded hole 2 (3). The six outer liquid return channels (5) are distributed in a circular array with the inner liquid inlet channel (4) as the center. The valve body also includes: a central rotating block (6) located in the valve body (1), six liquid return holes (7) connected to the outer liquid return channels (5) are distributed in a circular array on the central rotating block (6), a valve core assembly (8) is passed through the central rotating block (6), and a driving assembly (9) adapted to the valve core assembly (8) and the central rotating block (6) is installed near the end of the threaded hole 2 (3) of the inner liquid inlet channel (4). When the driving assembly (9) is reset, the valve core assembly (8) blocks the inner liquid inlet channel (4) near the end of the threaded hole 1 (2), and at the same time, the liquid return hole (7) is staggered with the outer liquid return channel (5), and the outer liquid return channel (5) is blocked. The valve core assembly (8) includes a rod-shaped valve core (13), the valve core (13) is semi-spherical near one end of the threaded hole (2), the inner wall of the inner liquid inlet channel (4) near one end of the threaded hole (2) is closed near one end of the threaded hole (2) to adapt to the sealing of the valve core (13) near one end of the threaded hole (2), the valve core (13) is hollow near the second end of the threaded hole (3), a sealing ring seat (14) is sleeved on the valve core (13), the sealing ring seat (14) is rotatably connected to the inner wall of the inner liquid inlet channel (4) to seal the installation chamber (29), the center rotating block (6) is installed on the sealing ring seat (14), the side end of the valve core (13) is provided with a liquid inlet (15) connected thereto, the inner ring end of the sealing ring seat (14) is circularly arrayed with limit card grooves, the limit card strip (16) is inserted into the limit card groove and fixedly connected to the valve core (13); The driving assembly (9) comprises: a screw plug (17) installed on the inner liquid inlet channel (4) near the two ends of the threaded hole (3), the screw plug (17) is provided with an internal threaded hole (18) connected to the inner liquid inlet channel (4); an internal ferrule (19) is fixedly installed on the screw plug (17) and connected to the internal threaded hole (18); a slide plate (20) is slidably installed on the inner wall of the inner liquid inlet channel (4), and the center end of the slide plate (20) is integrally formed with an internal groove (21), and the internal groove (21) The bottom end of the inner groove (21) is protruded toward the screw plug (17), the outer sleeve (22) is installed on the bottom end of the inner groove (21), the outer sleeve (22) is sleeved on the inner sleeve (19), the return spring (23) is sleeved on the outer sleeve (22), and is arranged between the bottom end of the inner groove (21) and the screw plug (17); the central liquid inlet pipe (24) is fixedly installed on the central end of the inner groove (21), the central liquid inlet pipe (24) passes through the outer sleeve (22), and extends into the inner sleeve (19).

2. A downhole dual-channel check valve according to claim 1, characterized in that: The valve body (1) is composed of a detachable left valve body (10) and a right valve body (11). The first threaded hole (2) is located on the left valve body (10), and the second threaded hole (3) is located on the right valve body (11). An installation chamber (29) for installing a center rotating block (6) is provided at the end of the left valve body (10) away from the first threaded hole (2).

3. A downhole dual-channel check valve according to claim 2, characterized in that: A sealing ring (12) adapted to be connected to the central rotating block (6) is installed on the inner wall of the installation chamber (29).

4. A downhole dual-channel check valve according to claim 1, characterized in that: The driving assembly (9) further comprises: four wedge-shaped top blocks (25) distributed in a circular array in the inner groove (21) with the central liquid inlet pipe (24) as the center, and a first inclined surface (251) and a second inclined surface (252) are provided adjacent to each other on the wedge-shaped top block (25); four wedge-shaped top rods (26) are integrally installed in a circular array on the valve core (13) near the second end of the threaded hole (3), and the wedge-shaped top rod (26) is bent at an obtuse angle near the end of the valve core (13). The end of the wedge-shaped push rod (26) away from the valve core (13) extends into the inner groove (21) and is adapted to the first inclined surface (251). The end of the wedge-shaped push rod (26) away from the valve core (13) is slidably connected to the central liquid inlet pipe (24). Four wedge-shaped push rods (27) are installed in a circular array on the sealing ring seat (14) near the second end of the threaded hole (3). The end of the wedge-shaped push rod (27) away from the sealing ring seat (14) extends into the inner groove (21) and is adapted to the second inclined surface (252).

5. A downhole dual-channel check valve according to claim 4, characterized in that: The first inclined surface (251) has a smaller slope than the second inclined surface (252).

6. A downhole dual-channel check valve according to claim 1, characterized in that: A plurality of guide sleeve rods (28) are also connected between the slide plate (20) and the screw plug (17).

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