Method for draining water from a mine strong aquifer

Abstract

The application discloses a mine strong aquifer water draining method, comprising the following steps: step one, determining the position and drilling structure of vertical large-diameter water draining well; step two, drilling and excavating the vertical well to the bottom of the strong aquifer by following the pipe; step three, making a water filtering sleeve; step four, lowering the water filtering sleeve and laying a grouting pipe; steps five to seven, gravel grouting well cementation; step eight, lowering a gas bag and inflating; step nine, determining the position of long-distance horizontal well; step ten, excavating the horizontal well pilot hole section and the horizontal well water draining section; step eleven, back-acting the horizontal well sleeve; step twelve, taking out the gas bag; step thirteen, cutting off the horizontal well sleeve in the vertical well; step fourteen, salvaging the sediment; and step fifteen, opening the horizontal well water draining section. The vertical large-diameter water draining well and the multiple water draining combined wells realize the combination of treatment and drainage of the burned and altered rock water, the burned and altered rock water can be self-flowing drained, the burned and altered rock water head is reduced, the threat of the burned and altered rock water to the coal mining is reduced, and the treatment and drainage cost is reduced.

Description

Technical Field

[0001] This invention belongs to the field of coal mine water hazard prevention and water resource utilization technology, specifically relating to a method for draining water from strong aquifers in mines. Background Technology

[0002] After coal resources are lost due to coal burning, the rock strata within a certain range of the coal seam roof are melted, sintered, baked, and collapsed, forming metamorphic rock. Metamorphic rock has well-developed and interconnected rock fissures and is highly water-bearing below the groundwater level, posing a significant threat and impact on the mining of the side slopes, especially the underlying coal seam.

[0003] In some coal mines in the western mining area, large-scale burning zones have developed, with the upper coal seams completely burned. When mining within the same seam encounters insufficient protective coal pillar thickness, water inrush accidents are prone to occur in the burning rocks on the sidewalls. When the lower coal face enters below the burning zone, water inrush accidents are prone to occur in the burning rocks on the roof, making the problem of burning rock water hazards increasingly serious. As mining gradually progresses from areas with simpler conditions to areas with more complex conditions, the problem of burning rock water hazards becomes increasingly prominent. Affected by burning rocks, a large amount of burning rock water enters the mine during coal mining, threatening safe production and increasing high drainage and water treatment costs, resulting in a huge waste of precious groundwater resources.

[0004] To effectively prevent and control water hazards in sintered rock in coal mines and protect groundwater resources, and to achieve the goals of ensuring mine safety, reducing mine water inflow, and effectively utilizing groundwater resources in green mining, it is urgent to develop a drainage method for sintered rock with strong aquifers. This method would enable the prevention and comprehensive utilization of water hazards in sintered rock, ensure green, safe, and efficient coal mine production, and solve the widespread problem of water hazards in sintered rock in Northwest China. Summary of the Invention

[0005] The main objective of this invention is to address the aforementioned technical problems in the existing technology and provide a method for draining water from strong aquifers in mines. This method overcomes the shortcomings of existing technologies for controlling water hazards on coal seam roofs and enables the construction of a large-diameter water source well in the strata near the coal mining subsidence area of ​​the upper coal face, with a water supply capacity of not less than 100 m³. 3 / h, the mine is free from roof water hazards from construction to closure, which can improve the control of the strata above the lower coal seam and provide a basis for subsequent subsidence area management.

[0006] To achieve the above-mentioned technical objectives, the present invention employs the following technical solution:

[0007] A method for draining water from a strong aquifer in a mine, the method comprising the following steps:

[0008] Step 1: Based on the topographic and geological conditions, and combined with geophysical exploration and drilling methods, determine the planar location and borehole structure of the vertical large-diameter drainage well. The vertical large-diameter drainage well includes a single drainage well or multiple drainage combined wells. The multiple drainage combined wells include a central well and multiple peripheral wells.

[0009] Step 2: Using the full casing full-rotation drilling process, penetrate the upper strata and place the bottom of the hole drilled with the construction casing below the bottom plate of the strong aquifer.

[0010] Step 3: Fabricate a filter sleeve with equal length and hole depth. Set the filter sleeve into a perforated section that allows water to enter at the depth below the bottom plate of the aquifer and the section corresponding to the strong aquifer.

[0011] Step 4: Lower the filter sleeve to the bottom of the hole and lift the construction sleeve so that the bottom of the construction sleeve is slightly lower than the bottom plate of the aquifer. Multiple annular grouting pipes and one bottom grouting pipe are evenly arranged along the outside of the filter sleeve. The bottom grouting pipe passes through the opening at the bottom of the filter sleeve and is arranged horizontally or obliquely inside the filter sleeve.

[0012] Step 5: Inject grout into the filter sleeve through the bottom grouting pipe to seal the lower part of the filter sleeve, and wait for the grout to solidify;

[0013] Step 6: After the bottom of the filter sleeve is grouted, grout the outside of the filter sleeve through the ring grouting pipe until grout flows into the filter sleeve at the bottom of the perforated pipe section, and then stop grouting.

[0014] Step 7: Pull out the tool pipe and construction casing in sequence, and at the same time fill the bottom and section of the strong aquifer with gravel. Fill a section of clay in a ring above the gravel-filled strong aquifer, and inject cement slurry intermittently in a ring on the clay to cement the well.

[0015] Step 8: Insert an airbag at a certain position below the perforated section of the filter sleeve and inflate the airbag;

[0016] Step 9: Determine the location of a long-distance near-horizontal well around the ground side of the vertical large-diameter drainage well. The long-distance near-horizontal well includes the horizontal well pilot hole section and the horizontal well drainage section.

[0017] Step 10: Using a trenchless drilling rig, construct the horizontal well pilot section on the ground, and penetrate the vertical large-diameter drainage well from the section below the air bladder in the filter casing until the horizontal well drainage section is formed.

[0018] Step 11: Using a trenchless drill bit, pull back the horizontal well casing from the drainage hole of the horizontal well drainage section to the vertical large-diameter drainage well, and then continue pulling back to pull the horizontal well casing out from the horizontal well pilot hole section to the surface.

[0019] Step 12: Loosen the air vent valve of the airbag to release the air, then remove the airbag from the filter sleeve;

[0020] Step 13: Cut the horizontal well casing inside the vertical large-diameter drainage well along the wall of the filter casing, and install a plugging valve at the cut end on one side of the horizontal well pilot hole section.

[0021] Step Fourteen: Remove the borehole sediment from the filter casing in the vertical large-diameter drainage well;

[0022] Step 15: Open the drainage section of the horizontal well to complete the autonomous drainage of the pyromorphic rock aquifer.

[0023] In step ten, the horizontal well drainage section is formed as follows: for a single drainage well, continuous near-horizontal directional drilling is performed until it emerges from the concrete slope to form a horizontal well drainage section; for the central well in a multi-drainage combined well, continuous near-horizontal directional drilling is performed until it emerges from the concrete slope to form a horizontal well drainage section; for the peripheral wells, continuous near-horizontal directional drilling is performed until it connects to the central well or other peripheral wells to form multiple horizontal well drainage sections.

[0024] In step eleven, for the central well, a leak-proof gasket is also installed in the annular gap between the horizontal well casing and the concrete slope protection.

[0025] Step eleven also includes fixing the horizontal well casing at the concrete slope and installing a valve at the opening of the horizontal well casing.

[0026] Step thirteen also includes welding the connection between the vertical large-diameter drainage well and the long-distance near-horizontal well.

[0027] Among the multiple drainage wells, the central well has the highest water level in the pyrophyllite aquifer and the greatest draft in the aquifer above the pyrophyllite floor.

[0028] In step ten, the drainage section of the horizontal well of the outer well is connected to the filter casing below the perforated pipe section of the central well, and the drainage hole of the drainage section of the horizontal well of the outer well is higher than the outlet of the horizontal well inlet section of the central well.

[0029] The drilling structure of the vertical large-diameter dredging well in step one includes at least a tool pipe and a construction casing, wherein the tool pipe is drilled below the bedrock and the construction casing is drilled below the sintered rock floor; a filter casing is installed inside the construction casing, and the filter casing is flush with the construction casing.

[0030] In step three, the perforated pipe section is located 3m below the burnt rock section inside the filter sleeve and below the burnt rock, forming the filter section.

[0031] Step 10 involves excavating a slope at the drainage hole of the horizontal well drainage section, followed by backfilling and pouring concrete slope protection.

[0032] Compared with the prior art, the present invention has the following technical advantages:

[0033] 1. This invention changes the traditional approach to preventing water hazards in sintered rock by changing the underground drainage method of sintered rock water to pre-drainage on the surface, thereby reducing the water head in sintered rock in advance and reducing the threat of sintered rock water to coal mining.

[0034] 2. This invention achieves the combination of treatment and utilization of calcined rock water, using the clean calcined rock water that has been pre-drained from the surface for production, irrigation, or replenishment of surface rivers, which greatly reduces the amount of water discharged underground in coal mines and lowers the costs of coal mine drainage and water treatment.

[0035] 3. The water drainage method of the strong aquifer of sintered rock of the present invention realizes the gravity drainage of water in sintered rock without the need for pumping, and the operation process is green, efficient, environmentally friendly and safe.

[0036] 4. Simultaneously meeting the water needs for coal seam subsidence area treatment and ecological restoration in coal seam working faces, and capable of releasing water from a single well near the coal seam subsidence area of ​​the upper coal face with a flow rate of not less than 100m³. 3 / h.

[0037] 5. Achieve gravity-flow drainage in the central well of the stratum near the coal mining subsidence area of ​​the upper coal face.

[0038] 6. Horizontal directional drilling can also be used to link multiple vertical large-diameter dredging wells together with topography and geological conditions to achieve coal mining subsidence area treatment and ecological restoration. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the structure before cementing a single-well drainage well in the process flow of this invention.

[0040] Figure 2 This is a schematic diagram of the grouting cementing structure in the process flow of the present invention.

[0041] Figure 3 This is a schematic diagram of the airbag insertion and inflation structure in the process flow of the present invention.

[0042] Figure 4 This is a schematic diagram of a long-distance near-horizontal well structure in the process flow of the present invention.

[0043] Figure 5 This is a schematic diagram of the structure after cutting the horizontal well casing inside the vertical well in the process flow of the present invention.

[0044] Figure 6 This is a schematic diagram of the drainage state of the vertical large-diameter dredging well of the present invention.

[0045] Figure 7 This is a schematic diagram of the parallel arrangement of multiple drainage wells according to the present invention.

[0046] The numbers in the diagram represent the following meanings:

[0047] 1. Vertical large-diameter drainage well; 1-1. Filter casing; 1-2. Slotted pipe section; 2. Construction casing; 3. Annular grouting pipe; 4. Bottom grouting pipe; 5. Airbag; 6. Horizontal well pilot hole section; 7. Horizontal well drainage section; 8. Horizontal well casing; 9. Concrete slope protection; 10. Leakage prevention gasket; 11. Valve; 12. Tool pipe; 13. Plug valve.

[0048] The specific content of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Detailed Implementation

[0049] Following the above technical solutions, specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent modifications made based on the technical solutions of this application fall within the protection scope of the present invention.

[0050] Example 1:

[0051] See Figures 1-6 A method for draining water from a strong aquifer in a mine, the method comprising the following steps:

[0052] Step 1: Based on the topographic and geological conditions, and combined with geophysical exploration and drilling methods, determine the planar location and borehole structure of the vertical large-diameter drainage well 1.

[0053] This invention utilizes the sintered rock aquifer of the upper coal face as the target aquifer for the vertical large-diameter drawdown well 1. Simultaneously, the aquifer level of the sintered rock is high, and the aquifer above the sintered rock floor has a large draft. Due to the large water accumulation depth and strong to extremely strong water-bearing capacity of the sintered rock, and the presence of a water-proof protective coal pillar within the same coal seam, the sintered rock aquifer of the upper coal face remains intact after mining.

[0054] The upper coal seam is thick, and after mining, the water-conducting fracture zone will develop to the top interface of the bedrock. The aquifer in the weathered zone of the roof will collapse and fracture during mining of the upper coal face, resulting in poor aquifer stability. The bedrock weathered zone is not suitable as the target aquifer for vertical large-diameter drawdown well 1.

[0055] However, while theoretically the upper coal seam goaf can be used as a target stratum for water intake wells, in practice, it is not suitable as a water intake stratum for coal mining subsidence area remediation. One reason is that the water source for the old goaf water comes from the bedrock weathering zone. Since the aquifer in the bedrock weathering zone itself has low water-bearing capacity, the water intake from the wells is not guaranteed. Another reason is that the water quality of the old goaf water in the upper coal seam goaf is poor and cannot be directly pumped for use; it requires wastewater treatment before it can be released for use.

[0056] The vertical large-diameter drainage well 1 of this invention has a large diameter and high investment, so determining the well location is very important. Before formal drilling, it is necessary to construct an exploration hole to find out the geological structure of the predetermined location of the vertical large-diameter drainage well 1, as well as the elevation and lithology of the top and bottom plates of the pyroform, so as to provide a basis for the selection of the water source well location, drilling design and drilling construction.

[0057] First, the location and number of exploratory boreholes were selected. The boreholes were designed as a three-hole structure. The first borehole was required to penetrate through the aeolian sand and enter the soil layer. The second borehole was required to reach the fresh bedrock layer at the bottom of the igneous rock. The third borehole was a bare-hole pumping section with a diameter of not less than Φ91 mm, and the borehole was drilled to a final depth of 10 m into the fresh bedrock at the bottom of the igneous rock. By analyzing the flushing fluid consumption, igneous rock exposure, and pumping test results of the exploratory boreholes, the water supply capacity of the igneous rock formation in each borehole was comprehensively assessed. The borehole with the largest water volume was selected as the location of the large-diameter water source well.

[0058] The drilling structure of the vertical large-diameter dredging well 1 includes at least a tool pipe 12 and a construction casing 2, wherein the tool pipe 12 is drilled below the bedrock, and the construction casing 2 is drilled below the sintered rock floor; a filter casing 1-1 is installed inside the construction casing 2, and the filter casing 1-1 is flush with the construction casing 2.

[0059] Step 2: Using the full casing full-rotation drilling process, penetrate the upper layer and place the bottom of the drilling hole of the construction casing 2 below the bottom plate of the strong water-bearing layer;

[0060] This invention employs a non-interference drilling method that does not disturb the formation during construction. Currently, vertical large-diameter dredging wells generally use a full-casing full-rotation non-interference drilling method. This method utilizes a large-diameter casing for full-hole drilling. During drilling, a grab bucket or rotary drilling bit is used to excavate the bottom rock and soil from the middle of the casing. Then, the casing is driven down by a jacking machine for dry drilling. This process is repeated to complete the hole.

[0061] Step 3: Fabricate filter sleeve 1-1. The length and hole depth of filter sleeve 1-1 are equal. The section of the strong aquifer of the igneous rock and the depth below the bottom plate of the igneous rock aquifer are set as perforated pipe section 1-2 that can be filled with water.

[0062] Flower pipe section 1-2 is located in the sintered rock section where filter sleeve 1-1 is located and 3m below the sintered rock, forming a filter section inside the hole.

[0063] Step 4: Lower the filter sleeve 1-1 to the bottom of the hole and lift the construction sleeve 2 so that the bottom of the construction sleeve 2 is slightly lower than the bottom plate of the aquifer; multiple annular grouting pipes 3 and one bottom grouting pipe 4 are evenly arranged along the outside of the filter sleeve 1-1. The bottom grouting pipe 4 passes through the bottom opening of the filter sleeve 1-1 and is arranged horizontally or obliquely inside the filter sleeve 1-1.

[0064] Step 5: Grout into the filter sleeve 1-1 through the bottom grouting pipe 4 to seal the lower part of the filter sleeve 1-1, and wait for the grout to solidify;

[0065] Step 6: After the bottom of the filter sleeve 1-1 is grouted, the outside of the filter sleeve 1-1 is grouted through the annular grouting pipe 3 until grout flows into the filter sleeve 1-1 at the bottom of the perforated pipe section 1-2, and then the grouting is stopped.

[0066] Step 7: Pull out tool pipe 12 and construction casing 2 in sequence, and at the same time fill gravel at the bottom of the strong aquifer and the strong aquifer section. Fill a section of clay in a ring above the gravel-filled strong aquifer, and inject cement slurry intermittently in a ring on the clay to cement the well.

[0067] Step 8: Insert airbag 5 at a certain position below the perforated pipe section 1-2 in the filter sleeve 1-1 and inflate the airbag 5. The inflated airbag 5 can radially block the filter sleeve 1-1, and the calcined rock water seeping out of the filter section is blocked by the airbag 5 to avoid affecting the subsequent construction.

[0068] Step 9: Determine the location of a long-distance near-horizontal well around the vertical large-diameter drainage well 1. The long-distance near-horizontal well includes the horizontal well inlet section 6 and the horizontal well drainage section 7.

[0069] Step 10: Using a trenchless drilling rig, construct the horizontal well pilot hole section 6 on the ground, and penetrate the vertical large-diameter drainage well 1 from the section below the airbag 5 in the filter casing 1-1. Then continue continuous near-horizontal directional drilling, exiting from the concrete slope 9 to form the horizontal well drainage section 7. At the drainage hole of the horizontal well drainage section 7, brush the slope and excavate, and then backfill and pour the concrete slope 9.

[0070] Step 11: Using a trenchless drill bit, pull back the horizontal well casing 8 through the drainage hole of the horizontal well drainage section 7 to the vertical large-diameter drainage well 1. Then continue pulling back until the horizontal well casing 8 is pulled out from the horizontal well pilot hole section 6 to the ground. Install a leak-proof gasket 10 in the annular gap between the horizontal well casing 8 and the concrete slope 9 to prevent the discharged calcined rock water from seeping into the slope through the annular gap, causing soil erosion or even slope collapse. Fix the horizontal well casing 8 at the concrete slope 9 and install a valve 11 at the pipe opening of the horizontal well casing 8.

[0071] Step 12: Loosen the exhaust valve of airbag 5 to release the air, and then remove airbag 5 from the filter sleeve 1-1;

[0072] Step Thirteen: Professional personnel descend to the bottom of the vertical large-diameter drainage well 1, cut the horizontal well casing 8 inside the vertical large-diameter drainage well 1 along the pipe wall of the filter casing 1-1, and install a plugging valve 13 at the cut end on one side of the horizontal well inlet section 6. The plugging valve 13 is set to prevent the molten rock water in the well from accumulating in the horizontal well inlet section 6, and the plugging valve 13 can be opened at any time during later maintenance to repair and replace the damaged horizontal well casing 8.

[0073] Professionals welded the connection between the vertical large-diameter drainage well 1 and the long-distance near-horizontal well underground to prevent the igneous rock water accumulated in the well from seeping into the formation and even the mine through the fracture, thereby reducing the threat of igneous rock water to coal mining.

[0074] Step Fourteen: Remove the borehole sediment from the vertical large-diameter drainage well 1 from the filter casing 1-1;

[0075] Step 15: Open valve 11 to open the horizontal well drainage section 7 and complete the autonomous drainage of the pyromorphic rock aquifer.

[0076] Example 2:

[0077] This invention can also realize multi-well drainage system composed of multiple single-well drainage wells, such as... Figure 7 As shown, among the multiple drainage wells, the aquifer with the highest water level in the igneous rock where the vertical large-diameter drainage well is located, and the aquifer with the largest draft above the igneous rock floor, is the central well. Based on the topographic and geological conditions, multiple peripheral wells are arranged around it by horizontal drilling. The water head difference between the central well and the drainage hole of its own horizontal well drainage section 7 is large, and the water pressure is high, which is conducive to drainage. The drainage holes of the horizontal well drainage section 7 of the multiple peripheral wells are connected to the pipe wall of the filter casing 1-1 below the flower pipe section 1-2 of the central well. Alternatively, the multiple peripheral wells can be connected through the horizontal well drainage section 7, and finally connected to the central well. In the end, the igneous rock water collected by the peripheral wells is collected to the central well and then discharged from the central well, realizing the treatment and ecological restoration of the coal mining subsidence area of ​​the working face.

[0078] It should be noted that the drainage hole of the horizontal well drainage section 7 of the outer well is higher than the outlet of the horizontal well inlet section 6 of the central well, so as to prevent the calcined rock water in the central well from flowing back into the outer well.

Claims

1. A method for draining water from a strong aquifer in a mine, characterized in that: The method includes the following steps: Step 1: Based on the topographic and geological conditions, combined with geophysical exploration and drilling methods, determine the planar location and borehole structure of the vertical large-diameter drainage well (1). The vertical large-diameter drainage well (1) includes a single drainage well or multiple drainage combined wells. The multiple drainage combined wells include a central well and multiple peripheral wells. Step 2: Using the full casing full-rotation drilling process, penetrate the upper layer and place the bottom of the hole drilled by the construction casing (2) below the bottom plate of the strong water-bearing layer; Step 3: Fabricate a filter sleeve (1-1). The length and hole depth of the filter sleeve (1-1) are equal. Set the filter sleeve (1-1) into a perforated pipe section (1-2) that can be filled with water at the depth below the bottom plate of the aquifer and the strong aquifer section. Step 4: Lower the filter sleeve (1-1) to the bottom of the hole and lift the construction sleeve (2) so that the bottom end of the construction sleeve (2) is slightly lower than the bottom plate of the aquifer; multiple annular grouting pipes (3) and a bottom grouting pipe (4) are evenly arranged along the outside of the filter sleeve (1-1). The bottom grouting pipe (4) passes through the bottom opening of the filter sleeve (1-1) and is arranged horizontally or obliquely inside the filter sleeve (1-1); Step 5: Grout into the filter sleeve (1-1) through the bottom grouting pipe (4) to seal the lower part of the filter sleeve (1-1) and wait for the grout to solidify; Step 6: After the bottom grouting of the filter sleeve (1-1) is completed, grouting is carried out on the outside of the filter sleeve (1-1) through the annular grouting pipe (3) until grout flows into the filter sleeve (1-1) at the bottom of the perforated pipe section (1-2), and then grouting is stopped. Step 7: Pull out the tool pipe (12) and the construction casing (2) in sequence. At the same time, fill the bottom of the strong aquifer and the strong aquifer section with gravel. Fill a section of clay in a ring above the gravel-filled strong aquifer. Inject cement slurry intermittently in a ring on the clay to cement the well. Step 8: Insert the airbag (5) at a certain position below the flower tube section (1-2) in the filter sleeve (1-1) and inflate the airbag (5); Step 9: Determine the location of a long-distance near-horizontal well around the ground side of the vertical large-diameter drainage well (1). The long-distance near-horizontal well includes the horizontal well inlet section (6) and the horizontal well drainage section (7). Step 10: Using a trenchless drilling rig, construct the horizontal well pilot hole section (6) on the ground, and penetrate the vertical large-diameter drainage well (1) from the section below the airbag (5) in the filter casing (1-1) until the horizontal well drainage section (7) is formed. Step 11: Using a non-excavation drill bit, pull back the horizontal well casing (8) from the drainage hole of the horizontal well drainage section (7) to the vertical large-diameter drainage well (1), and then continue to pull back so that the horizontal well casing (8) is pulled out from the horizontal well pilot hole section (6) to the surface. Step 12: Loosen the exhaust valve of the airbag (5) to release the air, and then remove the airbag (5) from the filter sleeve (1-1); Step 13: Cut the horizontal well casing (8) inside the vertical large-diameter drainage well (1) along the pipe wall of the filter casing (1-1), and install the plugging valve (13) at the cut end on one side of the horizontal well inlet section (6). Step Fourteen: Remove the borehole sediment from the vertical large-diameter drainage well (1) from the filter casing (1-1); Step 15: Open the horizontal well drainage section (7) to complete the autonomous drainage of the pyromorphic rock aquifer.

2. The method for draining water from a strong aquifer in a mine as described in claim 1, characterized in that: In step ten, the horizontal well drainage section (7) is formed as follows: for a single drainage well, continuous near-horizontal directional drilling is performed until it emerges from the concrete slope (9) to form a horizontal well drainage section (7); for the central well in a multi-drainage combined well, continuous near-horizontal directional drilling is performed until it emerges from the concrete slope (9) to form a horizontal well drainage section (7); for the peripheral wells, continuous near-horizontal directional drilling is performed until it connects to the central well or other peripheral wells to form multiple horizontal well drainage sections (7).

3. The method for draining water from a strong aquifer in a mine as described in claim 2, characterized in that: In step eleven, for the central well, a leak-proof gasket (10) is installed in the annular gap between the horizontal well casing (8) and the concrete slope protection (9).

4. The method for draining water from a strong aquifer in a mine as described in claim 3, characterized in that: Step eleven also includes fixing the horizontal well casing (8) at the concrete slope protection (9) and installing a valve (11) at the pipe opening of the horizontal well casing (8).

5. The method for draining water from a strong aquifer in a mine as described in claim 2, characterized in that: Step thirteen also includes welding the connection between the vertical large-diameter descent well (1) and the long-distance near-horizontal well.

6. The method for draining water from a strong aquifer in a mine as described in claim 2, characterized in that: Among the multiple drainage wells, the central well has the highest water level in the pyrophyllite aquifer and the greatest draft in the aquifer above the pyrophyllite floor.

7. The method for draining water from a strong aquifer in a mine as described in claim 2, characterized in that: In step ten, the horizontal well drainage section (7) of the outer well is connected to the filter sleeve (1-1) below the flower pipe section (1-2) of the central well, and the drainage hole of the horizontal well drainage section (7) of the outer well is higher than the outlet of the horizontal well inlet section (6) of the central well.

8. The method for draining water from a strong aquifer in a mine as described in claim 1, characterized in that: The drilling structure of the vertical large-diameter dredging well (1) in step one includes at least a tool pipe (12) and a construction casing (2), wherein the tool pipe (12) is drilled below the bedrock and the construction casing (2) is drilled below the calcined rock bottom plate; a filter casing (1-1) is installed inside the construction casing (2), and the filter casing (1-1) is flush with the construction casing (2).

9. The method for draining water from a strong aquifer in a mine as described in claim 1, characterized in that: In step three, the flower tube section (1-2) is located 3m below the burnt rock section inside the hole and below the burnt rock in the filter sleeve (1-1), forming a filter section.

10. The method for draining water from a strong aquifer in a mine as described in claim 2, characterized in that: In step ten, the slope is brushed and excavated at the drainage hole of the horizontal well drainage section (7), and then backfilled and poured with concrete slope protection (9).

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