Coal seam gas extraction borehole sealing control system

Abstract

The application discloses a coal seam gas extraction drilling hole sealing control system and relates to the technical field of coal mine gas extraction. The system comprises a positioning pipe, a communication pipeline, a gas extraction pipe, an outer pushing ring surface, a fixed shaft, a stress sensing adjusting device, an inner pushing ring surface and a self-adapting sealing device. The communication pipeline is movably arranged in the positioning pipe and is internally connected with the gas extraction pipe. The outer pushing ring surface is movably arranged at the right end of the positioning pipe and is located at a drilling hole orifice. The fixed shaft is movably arranged on the positioning pipe and is fixedly connected with the right side surface of the outer pushing ring surface. The stress sensing adjusting device is fixedly arranged at the left end of the positioning pipe, is located in the drilling hole and is fixedly connected with the left end of the communication pipeline. The inner pushing ring surface is movably arranged on the positioning pipe and is fixedly connected with the right end of the stress sensing adjusting device. The self-adapting sealing device is linearly arranged and comprises multiple sealing devices which are movably arranged on the positioning pipe and are located between the outer pushing ring surface and the inner pushing ring surface. The application realizes automatic retreat of the sealing ring when the drilling hole is radially contracted, automatic following when the drilling hole is radially expanded and adaptation to shear deformation, thereby ensuring efficient sealing during the whole gas extraction process.

Description

Technical Field

[0001] This invention relates to the field of coal mine gas extraction technology, and more specifically, to a coal seam gas extraction borehole sealing control system. Background Technology

[0002] Coal seam gas drainage is a key technology for disaster management and resource utilization in coal mines. The sealing effect of the drainage borehole directly determines the gas drainage concentration and the service life of the borehole. In existing technologies, borehole sealing often uses solid sealing materials such as cement mortar and polyurethane, which are injected into the annular space of the borehole during construction and solidify to form a rigid seal. However, coal mining activities generate significant disturbance stress in the coal body around the borehole, causing dynamic changes in the borehole diameter: when mining stress increases, the borehole often experiences radial contraction or even collapse; when stress is relieved, the borehole may experience radial expansion or local displacement and shear deformation. Traditional solid sealing materials are rigid or low-elasticity materials, which cannot adapt to such repeated and irregular diameter changes—the seal is crushed during contraction, and detaches from the borehole wall during expansion, forming a leakage channel, ultimately leading to a sharp drop in gas drainage concentration, and in severe cases, complete borehole failure. Therefore, it is necessary to provide a coal seam gas drainage borehole sealing control system to solve the problems mentioned in the background technology. Summary of the Invention

[0003] To achieve the above objectives, the present invention provides the following technical solution: a sealing control system for coal seam gas drainage boreholes, comprising:

[0004] Positioning tube;

[0005] A connecting pipe is movable inside the positioning pipe, and an extraction pipe is connected inside the connecting pipe;

[0006] The outer push ring is moved and positioned at the right end of the positioning tube, located at the borehole opening;

[0007] The fixed shaft is mounted on the positioning tube and is fixedly connected to the right side of the outer push ring surface.

[0008] The stress-sensing adjustment device is fixed at the left end of the positioning tube, located inside the borehole, and is fixedly connected to the left end of the connecting pipe.

[0009] The inner pushing ring surface is movable and set on the positioning tube, and is fixedly connected to the right end of the stress sensing adjustment device;

[0010] Multiple adaptive sealing devices are arranged in a straight line, and are movable on the positioning tube, located between the outer pushing ring surface and the inner pushing ring surface.

[0011] Furthermore, preferably, the stress-sensing adjustment device includes:

[0012] The push shaft is movably mounted on the positioning tube and is fixedly connected to the left side of the inner push ring surface;

[0013] The movable annular surface is fixed to the left end of the push shaft;

[0014] The positioning component is fixedly connected to the positioning tube on the inner side of its left end, and slidably connected to the push shaft on the inner side of its right end.

[0015] The adjusting ring is fixed on the connecting pipe, and the right side is provided with an annular groove, which is slidably connected to the left end of the positioning component through the annular groove;

[0016] Multiple adjusting springs are arranged in a ring, and are fixedly connected to the adjusting ring surface and the moving ring surface;

[0017] The annular bladder, with an outer ring connecting the adjusting ring surface and the positioning component, contains hydraulic fluid inside.

[0018] Furthermore, preferably, the positioning component includes:

[0019] The fixed tube has its left end slidably connected to the annular groove on the adjusting ring surface, and its inner wall slidably connected to the moving ring surface.

[0020] Multiple connecting columns are arranged in a ring on the left side of the movable ring surface, spaced apart from the adjusting spring, and are used to fix and connect the fixing tube and the positioning tube.

[0021] The positioning ring is fixed to the right end of the fixed tube, slidably connected to the push shaft, and fixedly connected to the annular bladder.

[0022] Furthermore, as a preferred embodiment, the fixed tube is provided with multiple annularly distributed hydraulic channels, which are located at one end of the fixed tube adjacent to the positioning annular surface, on the right side of the moving annular surface, and connect the inner and outer sides of the fixed tube.

[0023] Furthermore, preferably, the adaptive sealing device includes:

[0024] The connecting frame is movable and mounted on the positioning tube.

[0025] Multiple deformation adjustment components are arranged in a ring and fixed on the outer frame of the connecting frame;

[0026] Two fitting ring surfaces are symmetrically distributed on the left and right sides, fitting against the two sides of the deformation adjustment component, and the inner wall of the fitting ring surface is provided with positioning holes corresponding to the deformation adjustment component.

[0027] A flexible connecting ring surface is provided corresponding to the fitting ring surface and is fixed to the outer ring of the fitting ring surface;

[0028] The sealing collar is fixedly connected at both ends to the outer ring of the flexible connecting ring on both sides, and its inner side is in contact with the deformation adjustment component.

[0029] Furthermore, preferably, the connection frame includes:

[0030] The movable tube is mounted on the positioning tube.

[0031] The flexible connecting ring surface has an inner ring fixed to the outer wall of the moving tube;

[0032] The inner frame of the polygon is fixed on the outer ring of the elastic connecting ring surface;

[0033] Multiple connectors are arranged in a ring and fixed at the outer corner of the polygonal inner frame;

[0034] A polygonal outer frame is coaxially arranged with a polygonal inner frame, and the inner corners are fixedly connected to the connectors. Each side of the polygonal outer frame corresponds to a deformation adjustment component.

[0035] Furthermore, preferably, the deformation adjustment component includes:

[0036] The rhomboid linkage consists of four mutually rotating linkages, two of which are symmetrically distributed and fitted onto the border of the polygonal frame.

[0037] Connecting shaft, the corresponding connecting point of the two rhomboid connecting rod groups;

[0038] There are four support surfaces corresponding to the connecting rod, which are rotatably mounted on the connecting shaft, and adjacent support surfaces are rotatably hinged to each other.

[0039] Furthermore, preferably, the deformation adjustment component further includes:

[0040] The external shaft is provided in two sets, symmetrically distributed front and back, with two shafts in each set symmetrically distributed left and right, and is fixedly connected to the ends of the two diagonally opposite connecting shafts;

[0041] Two adjusting rods are symmetrically distributed front and back and fixed on the edge of the polygonal frame. The two ends correspond to the positioning holes on the fitting ring surface. The adjusting rods are provided with symmetrically distributed connecting slides on the left and right sides, and the connecting slides correspond to the external shaft.

[0042] The buffer spring is installed inside the connecting slide and is connected to the left and right sides of the external shaft and the inner sides of both ends of the connecting slide, respectively.

[0043] Compared with the prior art, the beneficial effects of the present invention are:

[0044] In this invention, a hydraulic-spring dual-redundant mechanism consisting of an annular bladder and an adjusting spring in the stress-sensing adjustment device is used to achieve a bidirectional sensitive response to the radial contraction and expansion of the borehole, so that the sealing pressure can be automatically and smoothly adjusted according to the change of borehole diameter.

[0045] By coordinating the diamond-shaped connecting rod assembly and the buffer spring in the adaptive sealing device, a precise linear conversion between axial compression force and radial expansion and contraction is achieved, enabling the sealing ring to actively follow or appropriately retract when the orifice diameter changes, thus avoiding excessive compression or sealing failure.

[0046] By connecting multiple adaptive sealing devices in series and setting the elastic connecting ring surface in the connecting frame, segmented independent sealing in the drilling axis direction and flexible following during shear deformation are achieved, so that the overall sealing continuity can be maintained when there is local misalignment or bending.

[0047] By using the structural design of the fixed tube, connecting column and hydraulic channel in the positioning component, remote hydraulic transmission between the stress sensing point (annular bladder) and the pressure application point (moving annular surface) is achieved, simplifying the transmission path and improving the working reliability in harsh downhole environments.

[0048] By setting the support surfaces to be hinged together and the flexible connecting ring surface in the deformation adjustment component, the sealing collar can conform to the irregular hole wall of the drilled hole and compensate for the angle, so that the sealing contact pressure distribution is more uniform and effectively blocks local air leakage channels. Attached Figure Description

[0049] Figure 1 A schematic diagram of the overall structure of a sealing control system for coal seam gas extraction boreholes;

[0050] Figure 2 This is a schematic diagram of the stress-sensing adjustment device.

[0051] Figure 3 This is a schematic diagram of the positioning component structure;

[0052] Figure 4 Right view of the adaptive sealing device;

[0053] Figure 5 This is a schematic diagram of the adaptive sealing device.

[0054] Figure 6 This is a schematic diagram of the connecting frame structure;

[0055] Figure 7 This is a schematic diagram of the deformation adjustment component structure;

[0056] Figure 8 This is a schematic diagram showing the connection between the deformation adjustment component and the fitting ring surface;

[0057] In the diagram: 1. Positioning tube; 2. Connecting pipe; 3. Outer pushing annular surface; 4. Fixed shaft; 5. Stress-sensing adjustment device; 6. Inner pushing annular surface; 7. Adaptive sealing device; 51. Pushing shaft; 52. Moving annular surface; 53. Positioning component; 54. Adjusting annular surface; 55. Adjusting spring; 56. Annular bladder; 71. Connecting frame; 72. Deformation adjustment component; 73. Fitting annular surface; 74. Flexible connecting annular surface; 75. Sealing collar; 531. Fixed tube; 532. Connecting column; 533. Positioning annular surface; 534. Hydraulic channel; 711. Moving tube; 712. Elastic connecting annular surface; 713. Polygonal inner frame; 714. Connector; 715. Polygonal outer frame; 721. Rhomboid connecting rod assembly; 722. Connecting shaft; 723. Support surface; 724. External shaft; 725. Adjusting connecting rod; 726. Buffer spring; 731. Positioning hole. Detailed Implementation

[0058] Please see Figures 1 to 8 In this embodiment of the invention, a sealing control system for coal seam gas drainage boreholes includes:

[0059] Positioning tube 1;

[0060] The connecting pipe 2 is movable inside the positioning pipe 1, and the connecting pipe 2 is connected to an extraction pipe.

[0061] The outer push ring 3 is moved and set at the right end of the positioning tube 1, located at the borehole opening;

[0062] The fixed shaft 4 is movably mounted on the positioning tube 1 and is fixedly connected to the right side of the outer pushing ring surface 3;

[0063] The stress sensing adjustment device 5 is fixed at the left end of the positioning tube 1, located inside the borehole, and is fixedly connected to the left end of the connecting pipe 2.

[0064] The inner pushing ring 6 is movably mounted on the positioning tube 1 and is fixedly connected to the right end of the stress sensing adjustment device 5;

[0065] The adaptive sealing device 7 is provided in multiple linear arrangements, and is movably mounted on the positioning tube 1, located between the outer pushing ring surface 3 and the inner pushing ring surface 6.

[0066] In this embodiment, the stress sensing adjustment device 5 includes:

[0067] The push shaft 51 is movably mounted on the positioning tube 1 and is fixedly connected to the left side of the inner push ring surface 6;

[0068] The movable annular surface 52 is fixed to the left end of the push shaft 51;

[0069] The positioning component 53 is fixedly connected to the positioning tube 1 on the inner side of its left end, and slidably connected to the push shaft 51 on the inner side of its right end;

[0070] Adjusting ring 54 is fixed on the connecting pipe 2. The right side is provided with an annular groove, which is slidably connected to the left end of the positioning component 53 through the annular groove.

[0071] Multiple adjusting springs 55 are arranged in a ring and are fixedly connected to the adjusting ring surface 54 and the movable ring surface 52.

[0072] The annular bladder 56 is the outer ring connecting the adjusting ring surface 54 and the positioning component 53, and is equipped with hydraulic fluid inside.

[0073] In other words, after the system is sent to the specified drilling depth, the fixed shaft 4 and the positioning tube 1 are fixed, and then the outer pushing annular surface 3 is brought into contact with the adaptive sealing device 7 and the position is fixed. In the initial pre-tightening stage, the connecting pipe 2 is pulled to the right, and the adjusting annular surface 54 moves to the right accordingly. The adjusting spring 55 pushes the moving annular surface 52 and the pushing shaft 51 to the right. The pushing shaft 51 drives the inner pushing annular surface 6 to the right to compress the adaptive sealing device 7, so that the adaptive sealing device 7 expands radially and fits tightly with the hole wall. At the same time, since the positioning component 53 is fixed, the annular bladder 56 between the adjusting annular surface 54 and the positioning component 53 expands under the action of hydraulic fluid, so that the stress sensing adjustment device 5 fits with the hole wall. When the borehole diameter becomes smaller due to stress, that is, when the borehole shrinks, the hole wall squeezes the annular bladder 56, causing the bladder to shrink and the internal hydraulic fluid pressure to increase. The hydraulic fluid acts on the right side of the moving annular surface 52 via the positioning component 53, generating a leftward thrust. This thrust compresses the adjusting spring 55, causing the moving annular surface 52 to move to the left. This, in turn, causes the inner pushing annular surface 6 to move to the left via the push shaft 51, reducing the compressive force on the adaptive sealing device 7 and allowing the adaptive sealing device 7 to contract radially. This prevents excessive compression damage while adhering to the borehole wall. When the borehole diameter increases due to stress, i.e., when the borehole expands, the pressure of the borehole wall on the annular bladder 56 decreases. The moving annular surface 52 moves to the right under the action of the adjusting spring 55, applying pressure to the hydraulic fluid. Under the action of its own elasticity and the internal hydraulic fluid, the annular bladder 56 expands outward and adheres tightly to the borehole wall. At the same time, the push shaft 51 pushes the inner pushing annular surface 6 to the right, increasing the compressive force on the adaptive sealing device 7, causing it to expand radially and re-adhere to the enlarged borehole wall.

[0074] In a preferred embodiment, the annular bladder 56 and the adjusting spring 55 constitute a "hydraulic-spring" dual-redundant sensing mechanism. The annular bladder 56 directly senses changes in the radial pressure of the borehole, with a fast response speed. The adjusting spring 55 provides the basic preload and acts as a mechanical reset element. The two work together to make the system's response to changes in borehole diameter both sensitive and stable. The sliding fit between the annular groove on the adjusting ring surface 54 and the positioning component 53 ensures that the positioning component 53 remains axially fixed when the connecting pipe 2 moves and the borehole deforms, thus avoiding malfunctions.

[0075] In this embodiment, the positioning component 53 includes:

[0076] The left end of the fixed tube 531 is slidably connected to the annular groove on the adjusting ring surface 54, and the inner wall is slidably connected to the movable ring surface 52.

[0077] Multiple connecting columns 532 are arranged in a ring and located on the left side of the movable ring surface 52, spaced apart from the adjusting spring 55, and are fixedly connected to the fixing tube 531 and the positioning tube 1;

[0078] The positioning ring surface 533 is fixed to the right end of the fixed tube 531, slidably connected to the push shaft 51, and fixedly connected to the annular bladder 56.

[0079] In this embodiment, the fixed tube 531 is provided with a plurality of annularly distributed hydraulic channels 534. The hydraulic channels 534 are located at one end of the fixed tube 531 adjacent to the positioning annular surface 533, on the right side of the moving annular surface 52, and connect the inner and outer sides of the fixed tube 531.

[0080] In other words, the fixed tube 531 is rigidly fixed to the positioning tube 1 by the connecting column 532, becoming the supporting skeleton of the entire stress sensing adjustment device 5. The distance between the connecting column 532 and the adjusting ring surface 54 can meet the requirement that the adjusting ring surface 54 moves to the right to complete the initial pre-tightening work. The contact position between the connecting column 532 and the moving ring surface 52 is the minimum radial adjustment amount of the stress sensing adjustment device 5. When the adjusting ring surface 54 moves to the right, the left end of the fixed tube 531 slides relative to the annular groove of the adjusting ring surface 54, ensuring coaxiality. In the initial state, the moving ring surface 52 is located inside the right side of the fixed tube 531. Its right side space is connected to the annular bladder 56 through the hydraulic channel 534. When the annular bladder 56 is squeezed, the hydraulic fluid enters the interior of the fixed tube 531 through the hydraulic channel 534, directly pushing the right side of the moving ring surface 52 and generating a leftward thrust.

[0081] In a preferred embodiment, when the borehole diameter decreases due to stress (i.e., the borehole shrinks), the borehole wall compresses the annular bladder 56, causing it to contract. This increases the internal hydraulic pressure, and the hydraulic fluid flows into the fixed tube 531 through the hydraulic channel 534 on the positioning assembly 53. This hydraulic fluid acts on the right side of the moving annular surface 52, generating a leftward thrust. This thrust compresses the adjusting spring 55, pushing the moving annular surface 52 to the left. This, in turn, causes the inner pushing annular surface 6 to move to the left via the pushing shaft 51, reducing the compressive force on the adaptive sealing device 7 and allowing the adaptive sealing device to... The radial contraction of the 7th ring prevents excessive compression damage. When the borehole diameter increases due to stress, i.e., when the borehole expands, the pressure of the borehole wall on the annular bladder 56 decreases. Under the action of its own elasticity and internal hydraulic fluid, the annular bladder 56 expands outward and adheres tightly to the borehole wall. At this time, the elastic force of the adjusting spring 55 dominates, pushing the moving annular surface 52 to move to the right. The hydraulic fluid flows back from the inside of the fixed pipe 531 through the hydraulic channel 534 to the annular bladder 56, pushing the annular surface 6 to move to the right, increasing the compression force on the adaptive sealing device 7, causing it to expand radially and re-adhere to the enlarged borehole wall.

[0082] In this embodiment, the adaptive sealing device 7 includes:

[0083] The connecting frame 71 is movable and mounted on the positioning tube 1;

[0084] Multiple deformation adjustment components 72 are arranged in a ring and fixed to the outer frame of the connecting frame 71.

[0085] Two fitting ring surfaces 73 are symmetrically distributed on the left and right sides and fit against the two sides of the deformation adjustment component 72. The inner wall of the fitting ring surface 73 is provided with positioning holes 731 corresponding to the deformation adjustment component 72.

[0086] A flexible connecting ring surface 74 is provided corresponding to the fitting ring surface 73 and is fixed to the outer ring of the fitting ring surface 73;

[0087] The sealing collar 75 is fixedly connected at both ends to the outer ring of the flexible connecting ring surface 74 on both sides, and its inner side is in contact with the deformation adjustment component 72.

[0088] In other words, the connecting frame 71 serves as the basic skeleton, fitted onto the positioning tube 1 and capable of sliding axially. Multiple deformation adjustment components 72 are evenly distributed in a ring around the outer periphery of the connecting frame 71. Under the action of the left and right side contact ring surfaces 73, the multiple deformation adjustment components 72 synchronously extend and retract radially, thereby radially adjusting the adaptive sealing device 7. When the two side contact ring surfaces 73 are axially pressed by the inner pushing ring surface 6 and the outer pushing ring surface 3, the distance between the contact ring surfaces 73 decreases, forcing the deformation adjustment components 72 to expand radially. When the axial pressure decreases, the deformation adjustment components 72 contract radially under the action of their own elastic elements.

[0089] In a preferred embodiment, the sealing collar 75 is connected to the fitting collar 73 via a flexible connecting ring surface 74. Its inner wall is always in contact with the outer side of the deformation adjustment component 72. Therefore, the radial movement of the deformation adjustment component 72 will directly drive the sealing collar 75 to radially expand and contract, thereby tightly fitting or slightly separating from the borehole wall. The flexible connecting ring surface 74 is made of highly elastic rubber or polyurethane material, which allows the sealing collar 75 to maintain a sealed connection with the fitting collar 73 while moving radially, and can provide a certain angle compensation when the borehole is deformed unevenly. Each adaptive sealing device 7 integrates an independent radial deformation capability. Multiple devices can be used in series to divide the sealing responsibility in the borehole axis direction. Even if a certain seal fails locally due to extreme deformation, the remaining devices can still maintain the overall sealing effect.

[0090] In this embodiment, the connection frame 71 includes:

[0091] The movable tube 711 is movable and set on the positioning tube 1;

[0092] The elastic connecting ring 712 has its inner ring fixed to the outer wall of the moving tube 711;

[0093] The inner polygonal frame 713 is fixed on the outer ring of the elastic connecting ring surface 712.

[0094] Multiple connectors 714 are arranged in a ring and fixed at the outer corner of the polygonal inner frame 713.

[0095] The polygonal outer frame 715 is coaxially arranged with the polygonal inner frame 713, and is fixedly connected to the connector 714 at the inner corner. Each side of the polygonal outer frame 715 corresponds to a deformation adjustment component 72.

[0096] In other words, the moving tube 711 is fitted onto the positioning tube 1 and can slide freely along the axial direction. When subjected to pressure from the inner pushing annular surface 6 or the outer pushing annular surface 3, it transmits the axial force to the entire connecting frame 71. The elastic connecting annular surface 712 connects the moving tube 711 to the polygonal inner frame 713, allowing the polygonal inner frame 713 to have a certain radial offset and tilt relative to the positioning tube 1. The polygonal inner frame 713 and the polygonal outer frame 715 are rigidly connected by the connector 714 to fix the polygonal outer frame 715. Each side of the polygonal outer frame 715 serves as a mounting base surface for fixing a deformation adjustment component 72.

[0097] In a preferred embodiment, when the borehole undergoes shear deformation (axial bending), radial displacement occurs between adjacent adaptive sealing devices 7. The elastic connecting ring surface 712 can absorb these deformations, allowing the polygonal inner frame 713 to adjust with the borehole changes. At the same time, the deformation adjustment component 72 on the polygonal outer frame 715 can still maintain a relatively independent radial adjustment capability. The design of the elastic connecting ring surface 712 gives the entire sealing device a "flexible following" capability, enabling it to maintain overall sealing continuity even when the borehole axis bends, thus preventing the rigid sealing system from jamming or breaking when the borehole shifts.

[0098] In this embodiment, the deformation adjustment component 72 includes:

[0099] The rhomboid linkage group 721 consists of four mutually rotating linkages, two of which are symmetrically distributed and fitted onto the frame of the polygonal outer frame 715.

[0100] Connecting shaft 722, corresponding connecting point of the two rhomboid connecting rod groups 721;

[0101] There are four support surfaces 723 corresponding to the connecting rod, which are rotatably mounted on the connecting shaft 722, and adjacent support surfaces 723 are rotatably hinged to each other.

[0102] In this embodiment, the deformation adjustment component 72 further includes:

[0103] The external shaft 724 is provided in two sets symmetrically distributed front and back, and two sets are provided symmetrically distributed left and right in each set, which are fixedly connected to the ends of the two diagonally opposite connecting shafts 722;

[0104] Two adjusting rods 725 are symmetrically distributed front and back and fixed on the edge of the polygonal outer frame 715. Both ends correspond to the positioning holes 731 on the fitting ring surface 73. The adjusting rods 725 are provided with connecting slides symmetrically distributed left and right. The connecting slides correspond to the external shaft 724.

[0105] The buffer spring 726 is installed in the connecting slide and is connected to the left and right sides of the external shaft 724 and the inner sides of both ends of the connecting slide, respectively.

[0106] In a preferred embodiment, when the borehole expands radially under stress (the borehole diameter increases), the inner pushing annular surface 6 moves to the right, increasing the axial pressure of all adaptive sealing devices 7 between the outer pushing annular surface 3 and the inner pushing annular surface 6. The two side contacting annular surfaces 73 are axially pressed together and move closer to each other. Since the adjusting connecting rod 725 is fixed on the polygonal outer frame 715, the positioning hole 731 on the fixed contacting annular surface 73 forces the end of the adjusting connecting rod 725 to move into the positioning hole 731. In the connecting slide on the adjusting connecting rod 725, the buffer spring 726 located on the inner side between the outer shaft 724 and the end of the connecting slide is compressed. Since the outer shaft 724 is fixedly connected to the diagonal connecting shaft 722, when the two side contacting annular surfaces 73 move closer, the axial distance between the two outer shafts 724 decreases, driving the corresponding connecting shaft 7 in the two rhomboid connecting rod groups 721. As the 22 components move closer together, the "rhombus" shape of the rhombus connecting rod assembly 721 changes. The longer diagonal (radial) becomes longer, and the shorter diagonal (axial) becomes shorter. That is, the outer connecting shaft 722 moves radially outward, and the connecting shaft 722 drives the support surface 723 to move radially outward. The support surface 723 pushes outward synchronously. Since the adjacent support surfaces 723 are rotated and hinged to each other, they can form an approximately continuous arc surface or plane, which pushes the inner wall of the sealing ring 75 outward evenly, causing the sealing ring 75 to expand radially and fit tightly against the enlarged hole wall. It should be noted that when the deformation adjustment assembly 72 deforms, the spacing between two adjacent deformation adjustment assemblies 72 is set to ensure that they do not come into contact or conflict. The spacing between the polygonal outer frame 715 and the polygonal inner frame 713 ensures that the deformation adjustment assembly 72 does not come into contact with the polygonal inner frame 713.

[0107] In a preferred embodiment, when the borehole radially shrinks (hole diameter decreases) under stress, the inner pushing annular surface 6 moves to the left, the axial pressure decreases, the compressed buffer spring 726 rebounds, and the two ends of the adjusting connecting rod 725 move outwards towards the positioning hole 731. The buffer spring 726 pushes the outer shaft 724 to move outwards along the connecting slide, increasing the distance between the two mating annular surfaces 73. The diagonal connecting shafts 722 in the two rhomboid connecting rod assemblies 721 move away from each other, the radial diagonal of the rhomboid connecting rod assembly 721 shortens, the support surface 723 retracts radially inwards, and the sealing ring 75, due to its own elasticity and the reaction of the hole wall... Under the action of compression, it contracts inward to avoid excessive compression with the hole wall; when the borehole undergoes non-uniform deformation (misalignment or shearing), the elastic connecting ring surface 712 between multiple adaptive sealing devices 7 allows each device to independently fine-tune its axial position. When the borehole is locally misaligned, the contact ring surface 73 of each adaptive sealing device 7 is misaligned to a small extent with each other, causing the sealing ring 75 to always be in contact with the hole wall. Furthermore, there is still some contact between multiple contact ring surfaces 73. Under the control of the stress sensing adjustment device 5, a secondary adjustment is made through the deformation adjustment component 72 to adapt to the overall change in hole diameter again.

[0108] In practice, the system is first inserted into the borehole to a specified depth. Then, the fixed shaft 4 and the positioning tube 1 are fixed so that the outer pushing ring surface 3 fits against the adaptive sealing device 7. Next, the connecting pipe 2 is pulled to the right, and the adjusting ring surface 54 moves to the right accordingly. The adjusting spring 55 pushes the moving ring surface 52 and the pushing shaft 51 to the right. The pushing shaft 51 drives the inner pushing ring surface 6 to the right to compress the multiple adaptive sealing devices 7 located between the outer pushing ring surface 3 and the inner pushing ring surface 6. This causes the fitting ring surfaces 73 in each adaptive sealing device 7 to move closer to each other, forcing the diamond-shaped connecting rod group 721 in the deformation adjustment assembly 72 to expand radially. This pushes the sealing sleeve through the support surface 723. The ring 75 fits tightly against the borehole wall, and the annular bladder 56 expands and presses against the borehole wall under the action of hydraulic fluid, completing the initial seal. The extraction pipe is then inserted into the borehole through the connecting pipe 2 for gas extraction. When the borehole contracts radially due to mining stress, the borehole wall squeezes the annular bladder 56, causing it to contract. The internal hydraulic fluid pressure increases and flows into the fixed pipe 531 through the hydraulic channel 534, pushing the left side of the moving annular surface 52 to generate a leftward thrust. This thrust compresses the adjusting spring 55 and moves the moving annular surface 52 to the left. This, through the push shaft 51, drives the inner push annular surface 6 to move to the left, reducing the axial compressive force on the adaptive sealing device 7. The rebound spring 726 pushes the external shaft 724 outward along the connecting slide on the adjusting rod 725, increasing the distance between the two mating annular surfaces 73. The radial diagonal of the rhomboid connecting rod assembly 721 shortens, and the support surface 723 causes the sealing ring 75 to radially contract to adapt to the reduced borehole diameter and avoid excessive compression. When the borehole expands radially, the pressure of the borehole wall on the annular bladder 56 decreases, and the adjusting spring 55 rebounds, pushing the moving annular surface 52 to the right. The inner pushing annular surface 6 moves to the right, increasing the axial compression force on the adaptive sealing device 7, causing the mating annular surfaces 73 to move closer together. The end of the adjusting rod 725 enters the positioning hole 731 deeper and compresses the buffer spring 726. The external shaft 724... 24 drives the connecting shafts 722 to move closer together, the rhomboid connecting rod group 721 expands radially, and the support surface 723 pushes the sealing ring 75 to expand radially and re-fit against the enlarged hole wall; when the borehole undergoes non-uniform deformation such as shearing or misalignment, the elastic connecting ring surface 712 in the connecting frame 71 allows the polygonal inner frame 713 to be radially offset relative to the positioning tube 1, each adaptive sealing device 7 independently fine-tunes its axial position, and at the same time, the soft connecting ring surface 74 provides compensation, so that the sealing ring 75 always fits against the hole wall, maintaining the overall sealing effect, and under the control of the stress sensing adjustment device 5, it is adjusted again by the deformation adjustment component 72 to adapt to the overall change in hole diameter.

[0109] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A sealing control system for coal seam gas drainage boreholes, characterized in that: include: Positioning tube (1); The connecting pipe (2) is movable inside the positioning pipe (1), and the connecting pipe (2) is connected to the extraction pipe; The outer push ring (3) is moved and set at the right end of the positioning tube (1), located at the borehole opening; The fixed shaft (4) is moved and set on the positioning tube (1) and is fixedly connected to the right side of the outer pushing ring surface (3); The stress sensing adjustment device (5) is fixed at the left end of the positioning tube (1), located inside the borehole, and is fixedly connected to the left end of the connecting pipe (2). The inner pushing ring surface (6) is moved and set on the positioning tube (1), and is fixedly connected to the right end of the stress sensing adjustment device (5); The adaptive sealing device (7) is provided in multiple linear distributions, and is movable on the positioning tube (1), and is located between the outer pushing ring surface (3) and the inner pushing ring surface (6).

2. The sealing control system for coal seam gas drainage boreholes according to claim 1, characterized in that: The stress-sensing adjustment device (5) includes: The push shaft (51) is movably mounted on the positioning tube (1) and is fixedly connected to the left side of the inner push ring surface (6); The movable annular surface (52) is fixed to the left end of the push shaft (51); The positioning component (53) is fixedly connected to the positioning tube (1) on the inner side of its left end, and slidably connected to the push shaft (51) on the inner side of its right end; Adjusting ring (54) is fixed on the connecting pipe (2). The right side is provided with an annular groove, which is slidably connected to the left end of the positioning component (53) through the annular groove. Adjusting springs (55) are arranged in a ring, and are fixedly connected to adjusting ring surface (54) and moving ring surface (52). The annular bladder (56) is connected to the outer ring of the adjusting ring surface (54) and the positioning component (53), and is equipped with hydraulic fluid inside.

3. The sealing control system for coal seam gas extraction boreholes according to claim 2, characterized in that: The positioning component (53) includes: The fixed tube (531) is slidably connected at its left end to the annular groove on the adjusting ring surface (54), and its inner wall is slidably connected to the moving ring surface (52); Multiple connecting columns (532) are arranged in a ring and located on the left side of the movable ring surface (52), spaced apart from the adjusting spring (55), and fixedly connected to the fixing tube (531) and the positioning tube (1). The positioning ring (533) is fixed to the right end of the fixed tube (531), slidably connected to the push shaft (51), and fixedly connected to the annular bladder (56).

4. The sealing control system for coal seam gas drainage boreholes according to claim 3, characterized in that: The fixed tube (531) is provided with a plurality of annularly distributed hydraulic channels (534). The hydraulic channels (534) are located at one end of the fixed tube (531) near the positioning annular surface (533), on the right side of the moving annular surface (52), and connect the inner and outer sides of the fixed tube (531).

5. A sealing control system for coal seam gas drainage boreholes according to claim 1, characterized in that: The adaptive sealing device (7) includes: The connecting frame (71) is movable and set on the positioning tube (1); Multiple deformation adjustment components (72) are arranged in a ring and fixed on the outer frame of the connecting frame (71); Two fitting ring surfaces (73) are symmetrically distributed on the left and right sides and fit against the two sides of the deformation adjustment component (72). The inner wall of the fitting ring surface (73) is provided with positioning holes (731) corresponding to the deformation adjustment component (72). A flexible connecting ring surface (74) is provided corresponding to the fitting ring surface (73) and fixed on the outer ring of the fitting ring surface (73); The sealing collar (75) is fixedly connected at both ends to the outer ring of the flexible connecting ring surface (74) on both sides, and its inner side is in contact with the deformation adjustment component (72).

6. A sealing control system for coal seam gas drainage boreholes according to claim 5, characterized in that: The connection frame (71) includes: The movable tube (711) is movable on the positioning tube (1); The elastic connecting ring (712) has its inner ring fixed to the outer wall of the moving tube (711); The inner polygonal frame (713) is fixed on the outer ring of the elastic connecting ring surface (712); The connectors (714) are arranged in a ring and are fixed at the outer corner of the polygonal inner frame (713); The polygonal outer frame (715) is coaxially arranged with the polygonal inner frame (713), and is fixedly connected to the connector (714) at the inner corner. Each side of the polygonal outer frame (715) corresponds to a deformation adjustment component (72).

7. A sealing control system for coal seam gas drainage boreholes according to claim 6, characterized in that: The deformation adjustment component (72) includes: The rhomboid linkage (721) consists of four mutually rotating linkages, two of which are symmetrically distributed and fitted onto the border of the polygonal frame (715); Connecting shaft (722), corresponding connecting rod connection point in the two rhomboid connecting rod groups (721); There are four support surfaces (723) corresponding to the connecting rod, which are rotatably mounted on the connecting shaft (722), and adjacent support surfaces (723) are rotatably hinged to each other.

8. A sealing control system for coal seam gas extraction boreholes according to claim 7, characterized in that: The deformation adjustment assembly (72) further includes: The external shaft (724) is provided in two sets symmetrically distributed front and back, and two sets are provided symmetrically distributed left and right in each set, which are fixedly connected to the ends of the two diagonally opposite connecting shafts (722); Two adjusting rods (725) are symmetrically distributed in front and back and fixed on the frame of the polygonal outer frame (715). Both ends correspond to the positioning holes (731) on the fitting ring surface (73). The adjusting rods (725) are provided with connecting slides symmetrically distributed in the left and right, and the connecting slides correspond to the external shaft (724). A buffer spring (726) is installed in the connecting slide and is connected to the left and right sides of the external shaft (724) and the inner sides of both ends of the connecting slide, respectively.

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