Underground double-channel check valve

Abstract

The invention relates to the technical field of petroleum production downhole tools, and discloses a downhole dual-channel check valve which comprises a valve body, a first threaded hole and a second threaded hole are oppositely formed in the valve body, and an inner liquid inlet channel and an outer liquid return channel are located in the valve body and communicated between the first threaded hole and the second threaded hole. The valve further comprises a center rotating block located in the valve body, six liquid return holes communicated with the outer liquid return channels are distributed in the center rotating block in a circular array mode, and a valve element assembly is arranged in the center rotating block in a penetrating mode. Driving assemblies matched with the valve element assembly and the center rotating block are installed at the two ends, close to the threaded hole, of the inner liquid inlet channel, when the driving assemblies reset, the valve element assembly blocks the end, close to the threaded hole, of the inner liquid inlet channel, meanwhile, the liquid return hole and the outer liquid return channel are staggered, and the outer liquid return channel is blocked. According to the underground double-channel check valve, the mechanical structure is simple, the stroke of the outer liquid return channel with the liquid return function is short, and therefore the structure of the valve control assembly is simplified.

Description

Technical Field

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

[0002] When double-layer coiled tubing is operated with tools, problems such as damage and breakage of the double-layer coiled tubing body caused by sudden accidents will be encountered. At this time, the 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 and cause a blowout accident.

[0003] Chinese patent document CN11878033A discloses a downhole dual-channel check valve, which is arranged between double-layer coiled tubings and communicated with the bottom of the well at its right end, and comprises a valve body, wherein a left first threaded hole and a left second threaded hole are provided at the left end of the valve body, and a left second through hole communicated with the left first threaded hole and a left first through hole communicated with the left second threaded hole are provided in the valve body; a right first threaded hole connected to the outer coiled tubing is provided at the right end of the valve body, and a valve hole extending to the left is provided in the valve body at the left end center of the right first threaded hole, and a screw plug is fixedly installed at the right end opening of the valve hole, and a right second threaded hole connected to the inner coiled tubing is provided in the screw plug, and a right second through hole communicated with the right first threaded hole is provided in the valve body, and a right first through hole communicated with the right second threaded hole is provided in the screw plug; and a valve control component is provided in the valve hole; the check valve can effectively close the channels of the inner and outer coiled tubings when an unexpected situation occurs, thereby preventing the well fluid from returning and preventing a blowout accident. 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 purpose, the present invention discloses a downhole dual-channel single-flow valve, including 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 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 also include: 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 in 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 one end of the inner liquid inlet channel near the threaded hole, and at the same time the liquid return hole is staggered with the outer liquid return channel, 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 a center rotating block is provided at one end of the left valve body away from the threaded holes.

[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 inner 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 valve core is hollow at both ends near the threaded hole, a sealing ring seat is provided on the valve core, the sealing ring seat is rotatably connected to the inner wall of the inner liquid inlet channel to seal the installation chamber, the center rotating block is installed on the sealing ring seat, a liquid inlet connected to the inner side of the valve core is opened, and the inner ring end of the sealing ring seat is provided with limiting card grooves in a circular array, the limiting card strip is inserted in the limiting card groove and is fixedly connected to the valve core.

[0008] Preferably, the drive assembly comprises:

[0009] A screw plug is installed at two ends of the inner liquid inlet channel close to the threaded hole, and an internal threaded hole communicating with the inner liquid inlet channel is provided in the screw plug;

[0010] Internal ferrule, which is fixedly mounted 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 disposed 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, and the central liquid inlet pipe passes through the outer ferrule and extends into the inner ferrule.

[0013] Preferably, the drive assembly further comprises:

[0014] A wedge-shaped top block, wherein four wedge-shaped top blocks are distributed in the inner groove in a circular array with the central liquid inlet pipe as the center, and a first inclined surface and a second inclined surface are adjacently arranged 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 at the two ends of the valve core close to the threaded hole, wedge-shaped push rod one is bent at an obtuse angle close to the end of the valve core, wedge-shaped push rod one extends into the inner groove away from the end of the valve core and is adapted to the first inclined surface setting, wedge-shaped push rod one is slidably 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 at the two ends of the sealing ring seat close to the threaded hole, wedge-shaped push rod two extends into the inner groove away from the end of 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, a plurality of 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 implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying 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 flowing);

[0021] Figure 3 It 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, the valve core assembly and the center rotating block of the present invention in a matching state;

[0023] Figure 5 It is an appearance diagram of the driving assembly, the valve core assembly and the center rotating block of the present invention in a matching 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 It is a schematic diagram of the installation of the wedge-shaped top block of the present invention 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. limit clamping strip; 17. screw plug; 18. internal threaded hole; 19. internal ferrule; 20. slide plate; 21. internal groove; 22. external ferrule; 23. reset 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 rod; 29. ​​installation chamber. DETAILED DESCRIPTION

[0027] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] Example

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

[0030] like Figures 1 to 7 As shown, a downhole dual-channel check valve provided in this embodiment includes a valve body 1, on which a threaded hole 1 2 and a 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 are connected between the threaded hole 1 2 and the 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, on which six liquid return holes 7 connected to the outer liquid return channels 5 are distributed in a circular array, 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 double-channel check valve, wherein the inner liquid inlet channel 4 is fed with liquid in the valve body 1, and the outer liquid return channel 5 is returned with liquid in the valve body 1, the valve core assembly 8 is used to block the inner liquid inlet channel 4, and the central rotating block 6 is used to block the outer liquid return channel 5. Under normal conditions, the well washing fluid is fed into the inner liquid inlet channel 4 of the valve body 1 from the threaded hole 12, and the pressure of the valve body 1 near the threaded hole 12 end is greater than the pressure of the valve body 1 near the threaded hole 23 end. At this time, the valve core assembly 8 releases the blockage of the inner liquid inlet channel 4, the valve core assembly 8 acts on the drive assembly 9, and drives the central rotating block 6 to rotate actively, the liquid return hole 7 is connected with the outer liquid return channel 5, and the central rotating block 6 releases the blockage of the outer liquid return channel 5. In the case of an emergency, when the bottom hole pressure is too high, the valve core assembly 8 is reset quickly under high pressure and blocks the inner liquid inlet channel 4. The drive assembly 9 resets and acts on the central rotating block 6 in the opposite direction, so that the liquid return hole 7 is staggered with the outer liquid return channel 5, and the outer liquid return channel 5 is blocked. The present invention discloses a downhole dual-channel check valve, which 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 23 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 detachably composed of a left valve body 10 and a right valve body 11, and the overall structure is easy to disassemble and assemble. 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 semi-spherical near the end of the threaded hole 12, the inner wall of the inner 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 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 opened 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 in the limit 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 delivered 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, and the well washing fluid is delivered into the inner liquid inlet channel 4 of the valve core 13 from the liquid inlet port 15. When the valve core 13 moves in the direction away from the threaded hole 2, it acts on the drive component 9, and 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 hole 7 is connected with the outer return liquid channel 5, and the center rotating block 6 releases the blockage of the outer return liquid channel 5, thereby realizing the return of oil in the outer return liquid channel 5. 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, 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, so that the central rotating block 6 rotates in the reverse direction, the return liquid hole 7 is offset from 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] A screw plug 17 is installed at the second and third ends of the inner liquid inlet channel 4 near the threaded hole, and an internal threaded hole 18 communicating with the inner liquid inlet channel 4 is provided in the screw plug 17;

[0044] An inner ferrule 19, which is fixedly mounted on the screw plug 17 and communicated with the inner 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 is protruded toward the screw plug 17. The outer sleeve 22 is mounted 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 disposed between the bottom end of the inner groove 21 and the screw plug 17.

[0046] A central liquid inlet pipe 24, which is fixedly mounted at the central end of the inner groove 21, and 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 threaded hole 23 end, the wedge-shaped push rod 1 26 is bent at an obtuse angle near the valve core 13 end, the wedge-shaped push rod 1 26 extends into the inner groove 21 away from the valve core 13 end, and is adapted to the first inclined surface 251 setting, the wedge-shaped push rod 1 26 is slidably connected to the central liquid inlet pipe 24 away from the valve core 13 end, and the four wedge-shaped push rods 27 are installed in a circular array on the sealing ring seat 14 near the threaded hole 23 end, the wedge-shaped push rod 27 extends into the inner groove 21 away from the sealing ring seat 14 end, and is adapted to the second inclined surface 252 setting.

[0050] The root of the wedge-shaped top block 25 is arranged in a plane 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 located 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 delivered 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, the well washing fluid is delivered into the valve core 13 from the liquid inlet port 15, and is delivered from the central liquid inlet pipe 24, the inner ferrule 19, the inner threaded hole 18 and the threaded hole 23, the reset spring 23 contracts, 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 abuts against the first inclined surface 251, and 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, so that the valve core 13 located in the sealing ring seat 14 cannot rotate. Then, the wedge-shaped push rod 1 26 is set against the first inclined surface 251, and can only drive the inner groove 21 and the slide plate 20 connected to the inner groove 21 to move in the contraction direction of the return spring 23. As the wedge-shaped push rod 27 is separated from the root of the wedge-shaped top block 25, the wedge-shaped push rod 1 26 is set against the first inclined surface 251, driving the valve core 13 connected to the wedge-shaped push rod 1 26, the sealing ring seat 14 sleeved on the valve core 13, and the central rotating block 6 connected to the sealing ring seat 14 to rotate in the installation chamber 29, and the wedge-shaped push rod 27 rotates to a position close to the second inclined surface 252, and the return liquid hole 7 is connected to the external return liquid channel 5. The external return liquid channel 5 is in a flow state, and the return liquid is sent back to the threaded hole 1 2 from the external return liquid channel 5 and the return liquid hole 7. As the wedge-shaped push rod 1 26 slides on the first inclined surface 251 to the root close to the wedge-shaped top block 25, the 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] When the bottom hole pressure is too high in an emergency, the valve core 13 is reset quickly under high pressure and blocks the inner liquid inlet channel 4. 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 is quickly set on 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 wedge-shaped top rod 27 are The central rotating block 6 connected with the valve 14 rotates in the opposite direction in the installation chamber 29, the wedge-shaped top rod 27 is located at the root of the wedge-shaped top block 25, the return hole 7 is staggered with the external return channel 5, the external return channel 5 is blocked, and after the valve core 13 is blocked on the internal liquid inlet channel 4, because the sealing ring seat 14 drives it to rotate in the opposite direction, the valve core 13 will rotate on the inner wall of the internal liquid inlet channel 4, thereby crushing the debris ejected from the bottom of the well to ensure that the valve core 13 completely blocks the internal liquid inlet channel 4. In this state, the internal liquid inlet channel 4 and the external return channel 5 are both in a blocked state.

[0054] By providing a single spring, the return spring 23, the structure of the valve control component 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, a plurality 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 the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A downhole dual-channel check valve, comprising a valve body (1), wherein the valve body (1) is provided with a first threaded hole (2) and a second threaded hole (3) opposite to each other, 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 arranged 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 arranged in a circular array on the central rotating block (6). A valve core assembly (8) is inserted into the central rotating block (6). 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). 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.

2. A downhole dual-channel check valve according to claim 1, characterized in that: The valve body (1) is composed of a left valve body (10) and a right valve body (11) which are detachable. 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 valve core assembly (8) comprises a rod-shaped valve core (13), the end of the valve core (13) near the threaded hole (2) is arranged in a hemispherical shape, the inner wall of the inner liquid inlet channel (4) near the threaded hole (2) is arranged in a closed-end type near the threaded hole (2) to adapt to the sealing of the valve core (13) near the threaded hole (2), the end of the valve core (13) near the threaded hole (3) is hollow, and a sealing ring 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 block the installation chamber (29). The central 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 slots. The limit strip (16) is inserted into the limit slot and fixedly connected to the valve core (13).

5. A downhole dual-channel check valve according to claim 4, characterized in that: The driving assembly (9) comprises: a screw plug (17) installed at two ends (3) of the inner liquid inlet channel (4) near the threaded hole, 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 protruding 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); the central liquid inlet pipe (24) is fixedly mounted on the central end of the inner groove (21), the central liquid inlet pipe (24) passes through the outer ferrule (22) and extends into the inner ferrule (19).

6. A downhole dual-channel check valve according to claim 5, characterized in that: The driving assembly (9) further comprises: four wedge-shaped top blocks (25) arranged in a circular array in the inner groove (21) with the central liquid inlet pipe (24) as the center, the wedge-shaped top blocks (25) being provided with a first inclined surface (251) and a second inclined surface (252) adjacent to each other; four wedge-shaped top rods (26) arranged in a circular array and integrally mounted on the valve core (13) near the second end of the threaded hole (3), the wedge-shaped top rods (26) being bent at an obtuse angle near the end of the valve core (13), and the wedge-shaped top rods (26) being provided with a first inclined surface (251) and a second inclined surface (252) adjacent to each other. 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 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).

7. A downhole dual-channel check valve according to claim 6, characterized in that: The first inclined surface (251) has a smaller inclination than the second inclined surface (252).

8. A downhole dual-channel check valve according to claim 5, characterized in that: A plurality of guide sleeve rods (28) are connected between the slide plate (20) and the screw plug (17).

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