Sealing method and sealing device

Abstract

The present application relates to the technical field of hole sealing, and particularly relates to a hole sealing method and a hole sealing device, the hole sealing method comprises the following steps: drilling a hole at a coal body to form a first hole section on the coal body, conveying a hole protection pipe into the first hole section, sealing a first bag between the hole protection pipe and the inner wall of the first hole section to form a closed first grouting cavity, injecting an expanding cement slurry into the first grouting cavity through a first grouting pipe to seal the hole, extending a drill bit into the hole protection pipe to drill a second hole section, the second hole section is communicated with the first hole section and is arranged along the extension direction of the first hole section in sequence, conveying an extraction pipe into the second hole section, sealing a second bag between the hole protection pipe and the extraction pipe, sealing a third bag between the extraction pipe and the inner wall of the second hole section to form a closed second grouting cavity, and injecting a flexible hole sealing slurry into the second grouting cavity through a second grouting pipe to seal the hole, the present application provides a hole sealing method, which can improve the hole sealing quality.

Description

Technical Field

[0001] This invention relates to the field of sealing technology, specifically to a sealing method and sealing device. Background Technology

[0002] Coal mine gas drainage is an important measure to reduce the amount of gas emitted from the mine and prevent gas explosions and coal and gas outbursts. During the gas drainage process, the quality of borehole sealing directly affects the gas drainage effect. Related technologies often use bag-type sealing or high-molecular organic material sealing. However, due to the influence of coal seam characteristics, ground stress, and underground construction during the gas drainage process, the borehole is prone to deformation, creating gas leakage channels and reducing the quality of borehole sealing. Summary of the Invention

[0003] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention propose a hole-sealing method that can improve the quality of hole sealing during drilling.

[0004] This invention also proposes a sealing device.

[0005] The sealing method of this invention includes: drilling a first hole in the coal body to form a first hole segment, and conveying a protective pipe to a first preset position within the first hole segment; sealing the space between the protective pipe and the inner wall of the first hole segment using a first slurry bag to form a closed first grouting cavity within the first hole segment; injecting a first slurry into the first grouting cavity using a first grouting pipe for a first sealing, wherein the first slurry is an expansive cement slurry; drilling a second hole by inserting a drill bit into the protective pipe to form a second hole segment in the coal body, wherein the second hole segment and the first hole segment are connected and arranged sequentially along the extension direction of the first hole segment, and conveying a extraction pipe to a second preset position within the second hole segment; sealing the space between the protective pipe and the extraction pipe using a second slurry bag, and sealing the space between the extraction pipe and the inner wall of the second hole segment using a third slurry bag to form a closed second grouting cavity between the second slurry bag and the third slurry bag; and injecting a second slurry into the second grouting cavity using a second grouting pipe for a second sealing, wherein the second slurry is a flexible sealing slurry.

[0006] The hole sealing method of this invention can improve the quality of hole sealing.

[0007] In some embodiments, the method of sealing the first grouting chamber within the first grouting section by using a first bladder between the protective tube and the inner wall of the first pore section includes: connecting a first grouting pipe and a grouting pump, and injecting a first grout into the first bladder at a first preset grouting pressure; gradually increasing the first preset grouting pressure until it equals a second preset grouting pressure, and then stopping the grouting into the first bladder, wherein the second grouting pressure is greater than the first grouting pressure.

[0008] In some embodiments, the first sealing of the hole by injecting the first grout into the first grouting cavity using the first grouting pipe includes: injecting the first grout into the first grouting cavity at a second preset grouting pressure; stopping the injection of grout into the first grouting cavity when at least part of the first grout is discharged from the hole protection pipe; and completing the first sealing of the hole after the first grout has solidified.

[0009] In some embodiments, the first pouch is an elastic pouch, the expansion rate of the first pouch is 100%-250%, and the strength of the first pouch after expansion is greater than 3 MPa.

[0010] In some embodiments, the distance between the second pouch and the third pouch is greater than 8 meters.

[0011] In some embodiments, the length of the protective tube is 4m-20m, the diameter of the protective tube is D1, 110mm≤D1≤300mm, and the diameter of the extraction tube is D2, 5cm<D1-D2≤40cm.

[0012] The sealing device of this invention includes: a protective tube adapted to extend into a first borehole section; a first bladder sleeved on the protective tube, the first bladder being expandable to abut against the inner wall of the first borehole section to form a closed first grouting cavity within the first borehole section; a first grouting pipe, one end of the first grouting pipe passing through the first bladder and extending into the first grouting cavity to inject a first grout into the first grouting cavity; a second bladder and a third bladder, the second bladder being located within the first borehole section, and the third bladder being located within the first borehole section. Within the two-hole section, the second hole section and the first hole section are connected and arranged sequentially along the extension direction of the first hole section. The second bag is adapted to be fitted onto the extraction pipe to seal the gap between the extraction pipe and the inner wall of the protective pipe. The third bag is adapted to be fitted onto the extraction pipe to seal the gap between the extraction pipe and the inner wall of the second hole section, so as to form a closed second grouting cavity between the second bag and the third bag. A second grouting pipe is provided, with one end of the second grouting pipe extending into the second grouting cavity to inject a second grout into the second grouting cavity.

[0013] The sealing device of this invention can improve the quality of borehole sealing.

[0014] In some embodiments, the sealing device further includes a check valve and a burst valve. The check valve is installed on the first grouting pipe and is used to prevent the grout in the first bag from flowing back. The burst valve is installed at the end of the first grouting pipe and is used to inject the first grout into the first grouting cavity when the grouting pressure is greater than or equal to the burst pressure of the burst valve.

[0015] In some embodiments, the protective tube includes a first protective tube segment and a plurality of second protective tube segments, wherein the plurality of second protective tube segments are connected sequentially along the length direction of the first hole segment.

[0016] In some embodiments, the sealing device further includes a baffle plate disposed on one end of the first protective pipe section near the orifice. The baffle plate is arranged perpendicularly to the first grouting pipe, and when the protective pipe extends into the first orifice section, the baffle plate is in contact with the coal wall. Attached Figure Description

[0017] Figure 1 This is a schematic flowchart of the sealing method according to an embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of the sealing device according to an embodiment of the present invention.

[0019] Figure 3 This is a schematic diagram of the first sealing of the hole in an embodiment of the present invention.

[0020] Figure 4 This is a schematic diagram of the second sealing of the hole in an embodiment of the present invention.

[0021] Figure label:

[0022] Coal body 100, first borehole section 200, second borehole section 300, extraction pipe 400, first slurry 500, second slurry 600

[0023] Protective tube 1, first protective tube section 11, external thread 111, second protective tube section 12, internal thread 121, baffle 13.

[0024] 2. First grouting bag; 3. First grouting pipe; 4. Check valve; 5. Bursting valve; 6. Pipe clamp.

[0025] Second bladder 7, third bladder 8, second grouting pipe 9. Detailed Implementation

[0026] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0027] The sealing method of this invention includes: drilling a first hole in the coal body to form a first hole segment, and conveying a protective pipe to a first preset position within the first hole segment; sealing the protective pipe and the inner wall of the first hole segment with a first slurry to form a closed first grouting cavity within the first hole segment using a first grouting pipe; injecting a first slurry into the first grouting cavity using a first grouting pipe for a first sealing, wherein the first slurry is an expansive cement slurry; drilling a second hole by inserting a drill bit into the protective pipe to form a second hole segment in the coal body, the second hole segment being connected to the first hole segment and arranged sequentially along the extension direction of the first hole segment, and conveying a extraction pipe to a second preset position within the second hole segment; sealing the protective pipe and the extraction pipe with a second slurry, and sealing the extraction pipe and the inner wall of the second hole segment with a third slurry to form a closed second grouting cavity between the second slurry and the third slurry; and injecting a second slurry into the second grouting cavity using a second grouting pipe for a second sealing, wherein the second slurry is a flexible sealing slurry.

[0028] Specifically, such as Figure 1 As shown, during the first drilling at the coal seam, the drilling rig is moved to the coal seam where the gas drainage borehole is to be drilled, and the first drilling operation is carried out. The length of the first borehole is greater than 4m but less than 20m. After the first drilling is completed, high-pressure air or high-pressure water is used to clean the drill cuttings inside the borehole, and then the casing is transported to the first preset position in the first borehole section. The first grouting pump is connected to the grouting pipe. Since the first sluice bag is fitted on the casing, the grouting pump injects the first grout into the first sluice bag at a relatively low grouting pressure to inflate the first sluice bag and block the borehole opening, thus sealing the first sluice bag between the casing and the inner wall of the first borehole section, forming a closed first grouting cavity in the first borehole section. When the grouting pressure is greater than the bursting pressure of the bursting valve installed at the end of the first grouting pipe, the grouting pump injects the first grout into the first grouting cavity through the first grouting pipe for the first sealing of the borehole. The drill bit is replaced, and the second drill bit is inserted into the borehole casing to form the second borehole section. The diameter of the second drill bit is smaller than the inner diameter of the borehole casing to ensure smooth insertion. After the second borehole is completed, drill cuttings are removed from the borehole using high-pressure air or water. The extraction pipe is then transported to the second preset position within the second borehole section. A second sealing bag is placed between the borehole casing and the extraction pipe for sealing, and a third sealing bag is placed between the extraction pipe and the inner wall of the second borehole section for sealing, ensuring the length of the second sealing. The traditional two-plug-one-injection process is used for sealing. The flexible sealing slurry is a physical polymer water-retaining material, such as a gel material, to improve the sealing effect of the second sealing. After completing the first and second sealing, the extraction pipe is connected to the downhole gas extraction system for downhole gas extraction.

[0029] For example, the inner wall of the protective tube has an irregular frosted surface, which increases the friction between the protective tube and the first and second bags and the inner wall of the protective tube, thereby improving the sealing stability of the first and second bags.

[0030] It should be noted that, due to the limited downhole space, it is inconvenient to use a hole-protecting pipe that is too long. The hole-protecting pipe in this embodiment of the invention includes a first hole-protecting pipe section and multiple second hole-protecting pipe sections. The first hole-protecting pipe section and the multiple second hole-protecting pipe sections have the same diameter and the same material. The length can be adjusted according to the actual use. That is, the length of the first hole-protecting pipe section and the second hole-protecting pipe section can be set to be the same or different. The length of the hole-protecting pipe is related to the length of the first borehole. That is, the longer the length of the first borehole, the longer the length of the hole-protecting pipe.

[0031] For example, to facilitate quick connection between protective tubes, the first protective tube segment and the second protective tube segment can be connected by threads. That is, the end of the first protective tube segment that extends into the first hole segment is provided with an external thread, one end of the second protective tube segment is provided with an internal thread that mates with the first protective tube segment, and the other end of the second protective tube segment is provided with an external thread. Multiple second protective tube segments can be quickly connected by threads, and the fact that multiple second protective tube segments have the same structure can also reduce the manufacturing cost of the protective tube.

[0032] In this embodiment of the invention, a protective pipe is placed at the borehole opening in the first section of the coal body, and expansive cement slurry is injected into the first section for rigid sealing to suppress the deformation of the drilled coal body and prevent the formation of air leakage channels. In the second section, i.e. the deep part of the borehole, a flexible sealing method is used to automatically seal the newly formed cracks and improve the quality of borehole sealing.

[0033] In some embodiments, a first sluice bag is used to seal between the protective tube and the inner wall of the first hole section to form a closed first grouting cavity in the first hole section, including: connecting the first grouting pipe and the grouting pump, and injecting the first grout into the first sluice bag at a first preset grouting pressure; gradually increasing the first preset grouting pressure until it is equal to a second preset grouting pressure, and then stopping the grouting into the first sluice bag, wherein the second grouting pressure is greater than the first grouting pressure.

[0034] Specifically, the quick connector of the first grouting pipe is connected to the grouting pump, and the grouting pump pumps the expanded cement grout into the first bladder at the first preset grouting pressure, and gradually increases the grouting pressure until the grouting pressure is equal to the second preset grouting pressure, at which point the grouting pump injects the expanded cement grout into the first grouting cavity.

[0035] In this embodiment of the invention, when the first grouting bag is placed in the first borehole section at a distance of more than 0.5 meters from the borehole opening to form the first grouting cavity, the grouting pump first injects grout into the first grouting bag at a relatively small grouting pressure to inflate the first grouting bag and block the borehole opening, and then gradually increases the grouting pressure until the grouting pressure is equal to the bursting pressure of the bursting valve, at which point the grouting pump injects grout into the first grouting cavity.

[0036] Understandably, the burst pressure of the rupture valve, i.e. the pressure of the second grouting pressure, cannot be too low to avoid the first bladder failing to effectively seal the orifice.

[0037] For example, a check valve is also installed on the first grouting pipe. The check valve is used to prevent the grout in the first bag from flowing back, that is, to ensure that the grout is still in the first bag when grouting is not performed, so that the first bag is kept in an inflated state.

[0038] In some embodiments, the first sealing of the hole by injecting first grout into the first grouting cavity using the first grouting pipe includes: injecting the first grout into the first grouting cavity at a second preset grouting pressure; stopping the injection of grout into the first grouting cavity when at least part of the first grout is discharged from the hole protection pipe; and completing the first sealing of the hole after the first grout has solidified.

[0039] Specifically, the second preset grouting pressure is equal to the bursting pressure of the bursting valve. When at least part of the first grout is discharged from the hole protection pipe, it indicates that the first grout in the first hole section has been saturated. Grouting into the first grouting cavity is stopped. After grouting is stopped, the hole is left to stand for 24 hours to allow the expansion cement to solidify, thus completing the first sealing of the hole.

[0040] Understandably, the first grout is made of expansive cement grout. After the expansive cement grout solidifies, it can seal the air leakage channels that are prone to occur at the borehole opening under the influence of ground stress and roadway coupling, thereby avoiding the formation of air leakage channels at the borehole opening and improving the sealing quality.

[0041] In some embodiments, the first pouch is an elastic pouch with an expansion rate of 100%-250% and an expansion strength greater than 3 MPa.

[0042] Specifically, the elastic bag can be a filter-accumulation type bag, with the expansion rate of the first bag being 100%-250% to ensure that the grout does not leak at the first bag, and the strength of the first bag after expansion is greater than 3MPa to avoid damage to the first bag after the expansion of the cement later.

[0043] In some embodiments, the distance between the second and third pouches is greater than 8 meters.

[0044] Specifically, the distance between the second and third bags is greater than 8 meters to ensure the sealing length of the second sealing hole and the sealing effect of the second sealing hole.

[0045] For example, the interval between the second bag and the first bag is about 0.5 meters to ensure the sealing length of the second sealing and improve the sealing effect.

[0046] For example, the second and third bags are water-retaining bags, which can also be called pressure-retaining bags.

[0047] In some embodiments, the length of the protective tube is 4m-20m, the diameter of the protective tube is D1, 110mm≤D1≤300mm, and the diameter of the extraction tube is D2, 5cm<D1-D2≤40cm.

[0048] Specifically, this embodiment of the invention limits the length of the protective pipe to ensure the sealing length for the first and second sealing operations, avoiding situations where the sealing length is too short and thus reduces the quality of the sealing. The diameter of the protective pipe is determined based on the diameter of the coal borehole. By considering the relationship between the diameter of the extraction pipe and the diameter of the protective pipe, it is ensured that the extraction pipe can smoothly extract gas while also smoothly passing through the protective pipe.

[0049] like Figures 2-4 As shown, the sealing device of this embodiment includes a protective tube 1, a first bladder 2, a first grouting pipe 3, a second bladder 7, a third bladder 8, and a second grouting pipe 9. The protective tube 1 is adapted to extend into the first hole section 200. The first bladder 2 is sleeved on the protective tube 1, and the first bladder 2 can expand to abut against the inner wall of the first hole section 200 to form a closed first grouting cavity within the first hole section 200. One end of the first grouting pipe 3 passes through the first bladder 2 and extends into the first grouting cavity to inject the first grout 500 into the first grouting cavity. The second bladder 7 is located within the first hole section 200, and the third bladder 8 is located within the second hole section 300. The second hole section 300 and the first hole section 200 are connected and extend along the extending direction of the first hole section 200 (e.g., ...). Figure 4 Arranged sequentially in a left-right direction (as shown), the second bag 7 is adapted to be fitted onto the extraction pipe 400 to seal the gap between the extraction pipe 400 and the inner wall of the protective pipe 1, and the third bag 8 is adapted to be fitted onto the extraction pipe 400 to seal the gap between the extraction pipe 400 and the inner wall of the second borehole section 300, so as to form a closed second grouting cavity between the second bag 7 and the third bag 8. One end of the second grouting pipe 9 extends into the second grouting cavity to inject the second grout 600 into the second grouting cavity.

[0050] Specifically, the right end of the protective tube 1 extends into the first hole section 200, and the first bag 2 is fitted over the first bag 2 and the first grouting pipe 3. The two ends of the first bag 2 are fixed to the protective tube 1 by the sealing pipe clamp 6 to ensure that the first bag 2 covers the protective tube 1. The first grout 500 is injected into the first bag 2 through the first grouting pipe 3 to make the first bag 2 expand and abut against the inner wall of the first hole section 200 to form the first sealing section. The right side of the sealing section forms the first grouting cavity, and the first grout 500 is injected into the first grouting cavity through the first grouting pipe 3. The second sluice bag 7 is fitted onto the extraction pipe 400 and abuts against the inner wall of the protective pipe 1 to form a second sealing section. The third sluice bag 8 is located to the right of the second sluice bag 7, and is fitted onto the extraction pipe 400 and abuts against the inner wall of the second hole section 300 to form a third sealing section. A second grouting cavity is formed between the second and third sealing sections, and a second grout 600 is injected into the second grouting cavity through the second grouting pipe 9. This embodiment of the invention improves the sealing efficiency by adopting a step-by-step grouting sealing method, which involves first injecting the first grout 500 into the first grouting cavity to form a first sealing, then drilling a second hole to form the second hole section 300, and then performing a second sealing in the second grouting cavity.

[0051] Since the first grout 500 is an expansive cement grout, the expansive cement grout has high strength after solidification, which can inhibit the deformation of the coal body 100 at the borehole opening, avoid the formation of gas leakage channels, and improve the borehole sealing quality. The second grout 600 is a flexible sealing grout, which can realize the automatic sealing of newly formed fractures and improve the borehole sealing quality. In this embodiment of the invention, by installing a protective pipe 1 at the borehole opening and injecting the first grout 500 into the first grouting cavity to form a rigid sealing, and injecting the second grout 600 into the second grouting cavity deep in the borehole to form a flexible sealing, it can cope with the deformation generated by the borehole and realize the automatic sealing of newly formed fractures, improve the sealing quality, and thus improve the gas extraction efficiency.

[0052] In some embodiments, the sealing device further includes a check valve 4 and a burst valve 5. The check valve 4 is installed on the first grouting pipe 3 and is used to prevent the grout in the first bag 2 from flowing back. The burst valve 5 is installed at the end of the first grouting pipe 3 and is used to inject the first grout 500 into the first grouting cavity when the grouting pressure is greater than or equal to the bursting pressure of the burst valve 5.

[0053] Specifically, the check valve 4 is located between the two sealing clamps 6 to prevent the grout in the first bladder 2 from flowing back. The burst valve 5 is installed at the end of the first grouting pipe 3, i.e., the right end of the first grouting pipe 3. When the grouting pressure is greater than or equal to the grouting pressure of the burst valve 5, the first grouting pipe 3 injects the first grout 500 into the first grouting chamber.

[0054] For example, a quick-connect fitting is installed on the left side of the first grouting pipe 3 to facilitate the connection between the first grouting pipe 3 and the grouting pump. The starting pressure of the burst valve 5 is greater than 0.8 MPa. The first bag 2 is an elastic bag with an expansion rate of 100%-250% and a strength greater than 3 MPa after expansion.

[0055] In some embodiments, the protective tube 1 includes a first protective tube segment 11 and a plurality of second protective tube segments 12, which are connected sequentially along the length of the first hole segment 200.

[0056] Specifically, the first protective hole section 11 and the multiple second protective hole sections 12 have the same diameter and the same material. Their lengths can be adjusted according to the actual use. That is, the lengths of the first protective hole section 11 and the second protective hole section 12 can be the same or different. The length of the protective hole section 1 is related to the length of the first drilling. That is, the longer the first drilling length, the longer the protective hole section 1. The multiple second protective hole sections 12 facilitate the installation of the protective hole section 1.

[0057] For example, to facilitate quick connection between the protective tubes 1, the first protective tube section 11 and the second protective tube section 12 can be connected by threads. That is, one end of the first protective tube section 11 that extends into the first hole section 200 is provided with an external thread 111, one end of the second protective tube section 12 is provided with an internal thread 121 that mates with the first protective tube section 11, and the other end of the second protective tube section 12 is provided with an external thread 111. Multiple second protective tube sections 12 can be quickly connected by threads, and the fact that multiple second protective tube sections 12 have the same structure can also reduce the manufacturing cost of the protective tube 1.

[0058] For example, the protective pipe 1 is made of flame-retardant and anti-static PE pipe, the inner wall of the protective pipe 1 has an irregular frosted surface, the diameter of the protective pipe 1 is 110-300mm, and the compressive strength of the protective pipe 1 is greater than 6MPa.

[0059] In some embodiments, the sealing device further includes a baffle 13, which is disposed on one end of the first hole protection pipe section 11 near the hole opening. The baffle 13 is arranged perpendicularly to the first grouting pipe 3. When the hole protection pipe 1 extends into the first hole section 200, the baffle 13 is in contact with the coal wall.

[0060] Specifically, an annular baffle 13 is provided on the left side of the first protective pipe 1. The radius of the annular baffle 13 is greater than the diameter of the first protective pipe 1 and is more than 10cm larger, so as to ensure that when the protective pipe 1 is located in the first hole section 200, the annular baffle 13 is in contact with the coal wall.

[0061] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0062] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0063] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0064] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0065] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0066] It is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A hole sealing device, characterized in that, The hole sealing device comprises: a hole protection pipe adapted to extend into the first hole section; a first bag sleeved on the hole protection pipe and inflatable to abut against the inner wall of the first hole section to form a closed first grouting cavity in the first hole section; a first grouting pipe having one end penetrating through the first bag and extending into the first grouting cavity to inject a first grout into the first grouting cavity, the first grout being an expansive cement grout; a second bag located in the first hole section and a third bag located in the second hole section, the second hole section being communicated with the first hole section and arranged in sequence along the extension direction of the first hole section, the second bag being adapted to be sleeved on the extraction pipe to seal the gap between the extraction pipe and the inner wall of the hole protection pipe, and the third bag being adapted to be sleeved on the extraction pipe to seal the gap between the extraction pipe and the inner wall of the second hole section to form a closed second grouting cavity between the second bag and the third bag; a second grouting pipe having one end extending into the second grouting cavity to inject a second grout into the second grouting cavity, the second grout being a flexible hole sealing grout; the right end of the hole protection pipe extends into the first hole section, the two ends of the first bag are fixed on the hole protection pipe by a sealing pipe clamp to ensure that the first bag wraps the hole protection pipe, the first grout is injected into the first bag through the first grouting pipe to inflate the first bag to abut against the inner wall of the first hole section to form a first sealing section, the first grouting cavity is formed on the right side of the sealing section, and the first grout is injected into the first grouting cavity through the first grouting pipe; the second bag is sleeved on the extraction pipe and can abut against the inner wall of the hole protection pipe to form a second sealing section, the third bag is located on the right side of the second bag and is sleeved on the extraction pipe to abut against the inner wall of the second hole section to form a third sealing section, the second grouting cavity is formed between the second sealing section and the third sealing section, and the second grout is injected into the second grouting cavity through the second grouting pipe; the inner wall of the hole protection pipe is an irregular frosted surface to increase the friction between the second bag and the inner wall of the hole protection pipe; the hole protection pipe comprises a first hole protection pipe section and a plurality of second hole protection pipe sections, and the plurality of second hole protection pipe sections are connected in sequence through threads in the length direction of the first hole section.

2. The hole closure device of claim 1, wherein, The hole sealing device further comprises a check valve and a burst valve, the check valve is installed on the first grouting pipe and used to prevent the grout in the first bag from flowing back, and the burst valve is installed at the end of the first grouting pipe and used to inject the first grout into the first grouting cavity when the grouting pressure is greater than or equal to the burst pressure of the burst valve.

3. The hole closure device of claim 1, wherein, The hole sealing device further comprises a baffle arranged on the first hole protection pipe section at one end close to the hole, the baffle is arranged perpendicularly to the first grouting pipe, and the baffle is attached to the coal wall when the hole protection pipe extends into the first hole section.

4. A method of sealing a hole, characterized by, The hole sealing method comprises: performing first drilling on the coal body to form a first hole section on the coal body and conveying a hole protection pipe to a first preset position in the first hole section; sealing the first bag between the hole protection pipe and the inner wall of the first hole section to form a closed first grouting cavity in the first hole section; injecting the first grout into the first grouting cavity by the first grouting pipe to perform the first hole sealing; extending the drill bit into the hole protection pipe to perform the second drilling to form a second hole section on the coal body, the second hole section and the first hole section being communicated and arranged in sequence along the extension direction of the first hole section, and conveying the extraction pipe to a second preset position in the second hole section; sealing the second bag between the hole protection pipe and the extraction pipe, and sealing the third bag between the extraction pipe and the inner wall of the second hole section to form a closed second grouting cavity between the second bag and the third bag; injecting the second grout into the second grouting cavity by the second grouting pipe to perform the second hole sealing.

5. The hole sealing method according to claim 4, characterized by, The sealing the first bag between the hole protection pipe and the inner wall of the first hole section to form a closed first grouting cavity in the first hole section comprises: connecting the first grouting pipe and the grouting pump, and injecting the first grout into the first bag at a first preset grouting pressure; gradually increasing the first preset grouting pressure until the second preset grouting pressure is reached, and stopping the grouting into the first bag.

6. The hole sealing method according to claim 5, characterized by, The injecting the first grout into the first grouting cavity by the first grouting pipe to perform the first hole sealing comprises: injecting the first grout into the first grouting cavity at the second preset grouting pressure; stopping the grouting into the first grouting cavity when at least part of the first grout is discharged from the hole protection pipe; waiting for the first grout to solidify to complete the first hole sealing.

7. The hole sealing method according to claim 6, characterized by, The first bag is an elastic bag, the expansion rate of the first bag is 100%-250%, and the strength of the first bag after expansion is greater than 3MPa.

8. The hole sealing method according to claim 4, wherein The interval distance between the second bag and the third bag is greater than 8m.

9. The hole sealing method according to claim 4, characterized by, The length of the hole protection pipe is 4m-20m, the diameter of the hole protection pipe is D1, 110mm≤D1≤300mm, and the diameter of the extraction pipe is D2, 5cm<D1-D2≤40cm.

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