Coal mine waterproof key layer reinforcement and seepage prevention method based on micro-seismic monitoring
By constructing a fracture network in the key water-resistant layer of a coal mine using microseismic monitoring and static fracturing techniques, and injecting grout to form a stone-like seepage-blocking zone, the problem of limited grout diffusion was solved, the waterproofing effect was improved, and costs and risks were reduced.
Patent Information
- Application Number
- CN202511674942.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-14
- Publication Date
- 2026-02-10
AI Technical Summary
When the overlying rock strata in the goaf of a coal mine are water-rich aquifers, the grout diffusion radius is small, resulting in insufficient seepage barrier area and poor waterproofing effect.
Microseismic monitoring was used to identify the fracture characteristics of the rock strata below the aquifer. Static fracturing solid explosive cartridges were placed in boreholes to form a primary fracture network. Static fracturing liquid explosives were injected to expand the secondary fracture network. Finally, grout was injected and solidified to form a stone-like impermeable zone.
It significantly improves the permeability of the key waterproof layer, forms a large-scale continuous rock-body seepage-blocking zone, enhances the integrity of the waterproof barrier, reduces reliance on high-pressure grouting equipment and the risk of rock mass instability, and provides an economical and reliable waterproofing solution.
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Figure CN121497426A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of rock strata technology, and in particular to a method for reinforcing and preventing seepage in key water-blocking layers of coal mines based on microseismic monitoring. Background Technology
[0002] When a water-rich aquifer exists in the overlying strata of a coal mine goaf, water-conducting fractures can easily penetrate the aquifer and the goaf, leading to sudden water inrush disasters. Grouting in the strata below the aquifer can reinforce the rock layer, and the solidified grout forms a seepage-blocking zone, which can be optimized as a key waterproofing layer. However, due to the low permeability of the rock layer, the grout diffusion radius is small, the seepage-blocking zone is insufficient, and the waterproofing effect is poor. Summary of the Invention
[0003] This disclosure aims to at least partially address one of the technical problems in the related art.
[0004] Therefore, the purpose of this disclosure is to provide a method for reinforcing and preventing seepage in key water-blocking layers of coal mines based on microseismic monitoring.
[0005] To achieve the above objectives, this disclosure provides a method for reinforcing and impermeable to the water-tight critical layer in coal mines based on microseismic monitoring, comprising: obtaining the fracture characteristics of the rock strata below the aquifer using microseismic monitoring, wherein the rock strata below the aquifer are located above the goaf and include the water-tight critical layer; when the fracture development height of the rock strata below the aquifer is greater than a preset height, drilling a borehole from the surface into the fracture zone of the water-tight critical layer; arranging multiple spaced static fracturing solid explosive cartridges at the water-tight critical layer of the borehole, the static fracturing solid explosive cartridges causing the borehole to radially expand the fractures and form a primary fracture network in the water-tight critical layer; injecting static fracturing liquid explosive into the primary fracture network, the static fracturing liquid explosive causing the primary fracture network to expand the fractures and form a secondary fracture network; injecting grout into the secondary fracture network, the grout solidifying to form a stone-like impermeable zone in the water-tight critical layer.
[0006] Optionally, the method further includes: after the grout has solidified, using microseismic monitoring to obtain the residual fractures in the impermeable zone of the stone body; when the number of residual fractures in the impermeable zone of the stone body is not greater than a preset number, determining that the water-tight key layer has been reinforced; when the number of residual fractures in the impermeable zone of the stone body is greater than the preset number, injecting grout into the secondary fracture network again and increasing the injection pressure of the grout so that the grout fills the residual fractures.
[0007] Optionally, the step of arranging multiple spaced static fracturing solid explosive cartridges at the water-tight critical layer of the borehole includes: applying an adhesive to the borehole wall; and sequentially pushing the multiple static fracturing solid explosive cartridges to the water-tight critical layer of the borehole based on a preset spacing.
[0008] Optionally, arranging multiple spaced static fracturing solid explosive cartridges at the water-tight critical layer of the borehole includes: arranging multiple water-activated static fracturing solid explosive cartridges at intervals at the water-tight critical layer of the borehole; and waiting for a preset expansion time to allow the static fracturing solid explosive cartridges to form the initial fracture network using the generated continuous expansion stress.
[0009] Optionally, the preset spacing ranges from 0.5m to 1.5m.
[0010] Optionally, the preset extension time ranges from 24h to 36h.
[0011] Optionally, injecting the static fracturing liquid into the primary fracture network includes: cleaning the residue inside the borehole; injecting the static fracturing liquid into the borehole at a first preset pressure and sealing the borehole opening, so that the static fracturing liquid fills the primary fracture network; and waiting for a preset propagation time, so that the static fracturing liquid utilizes the generated continuous expansion stress to form the secondary fracture network.
[0012] Optionally, injecting the static fracturing liquid agent into the primary fracture network includes: cleaning the residue in the borehole using a drilling rig; injecting the static fracturing liquid agent into the borehole at a first preset pressure using an injection pump and sealing the borehole opening using a liquid agent sealing device, so that the static fracturing liquid agent fills the primary fracture network.
[0013] Optionally, injecting the static fracturing liquid solution into the initial fracture network includes: mixing the static fracturing agent and water in a preset ratio to form the static fracturing liquid solution.
[0014] Optionally, injecting grout into the secondary fracture network includes: using a grouting pump to inject the grout into the borehole at a second preset pressure and using a grout sealing device to seal the borehole opening, so that the grout fills the secondary fracture network; and waiting for a preset solidification time to allow the grout to solidify and form a stone body.
[0015] The technical solution provided in this disclosure may include the following beneficial effects: Based on microseismic monitoring, the risk of water inrush in the rock strata below the aquifer is identified, and a step-by-step static fracturing process is implemented. Specifically, a static fracturing solid cartridge expands within the borehole to form an initial fracture network. Then, a static fracturing liquid agent is injected to penetrate along the initial fracture network and expand the fractures to form a secondary fracture network. This significantly improves the overall permeability of the critical water-resistant layer, solving the problem of limited grout diffusion in traditional grouting. The enhanced permeability of the rock strata allows the grout to fully diffuse and solidify, forming a large-scale and continuous rock-bound impermeable zone, thereby greatly improving the integrity of the waterproof barrier. This not only reduces reliance on high-pressure grouting equipment and saves energy costs, but also avoids the risk of rock mass instability caused by blasting or strong hydraulic fracturing, providing a reliable and economical solution for water inrush prevention in deep coal mines.
[0016] Additional aspects and advantages of this disclosure will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this disclosure. Attached Figure Description
[0017] The above and / or additional aspects and advantages of this disclosure will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, in which: Figure 1 This is a schematic flowchart of a method for reinforcing and preventing seepage in key water-blocking layers of coal mines based on microseismic monitoring, as proposed in an embodiment of this disclosure. Figure 2 This is a schematic diagram of the structure during the initial formation of the fracture network in a method for reinforcing and preventing seepage in key water-blocking layers of coal mines based on microseismic monitoring, as proposed in an embodiment of this disclosure. Figure 3 This is a schematic diagram of the secondary fracture network formation in a method for reinforcing and preventing seepage in key water-blocking layers of coal mines based on microseismic monitoring, as proposed in an embodiment of this disclosure. Figure 4 This is a schematic diagram of the structure during the formation of the seepage-blocking zone of the rock body in a method for reinforcing and blocking seepage-proofing key layers in coal mines based on microseismic monitoring, as proposed in an embodiment of this disclosure. As shown in the figure: 1. Drilling, 2. Static fracturing solid explosive cartridge, 3. Primary fracture network, 4. Static fracturing liquid explosive, 5. Secondary fracture network, 6. Stone body seepage barrier zone, 7. Injection pump, 8. Explosive sealing device, 9. Grouting pump, 10. Grout sealing device. 100, Coal seam; 200, Goaf; 300, Aquifer; 400, Water-blocking key layer; 500, Water-conducting fracture. Detailed Implementation
[0018] Embodiments of this disclosure are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are used only to explain this disclosure, and should not be construed as limiting this disclosure. Rather, embodiments of this disclosure include all variations, modifications, and equivalents falling within the spirit and scope of the appended claims.
[0019] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown in the embodiments of this disclosure, a method for reinforcing and preventing seepage in the critical water-blocking layer 400 of a coal mine based on microseismic monitoring is proposed, including: S1: The fracture characteristics of the rock strata below the aquifer 300 are obtained by microseismic monitoring. The rock strata below the aquifer 300 are located above the goaf 200 and include the water-blocking key layer 400. S2: When the height of the fracture development in the rock strata below the aquifer 300 is greater than the preset height, drill hole 1 is drilled from the surface into the fracture zone of the key aquifer 400. S3: Multiple static fracturing solid explosive cartridges 2 are arranged at intervals at the water-proof key layer 400 of borehole 1. The static fracturing solid explosive cartridges 2 cause the borehole 1 to expand the fractures radially and form an initial fracture network 3 in the water-proof key layer 400. S4: Inject static fracturing liquid agent 4 into the primary fracture network 3. The static fracturing liquid agent 4 causes the primary fracture network 3 to expand the fractures and form a secondary fracture network 5. S5: Inject grout into the secondary fracture network 5. After the grout solidifies, it forms a stone-like impermeable zone 6 in the key water-proof layer 400.
[0020] Understandably, the risk of water inrush in the rock strata below the aquifer 300 is identified based on microseismic monitoring, and a step-by-step static fracturing process is implemented. Specifically, a static fracturing solid cartridge 2 is expanded within borehole 1 to form an initial fracture network 3. Then, a static fracturing liquid agent 4 is injected to penetrate along the initial fracture network 3 and expand the fractures to form a secondary fracture network 5. This significantly improves the overall permeability of the critical water-resistant layer 400, solving the problem of limited grout diffusion in traditional grouting. The enhanced permeability of the rock strata allows the grout to fully diffuse and solidify, forming a large-scale and continuous rock-bound seepage barrier zone 6, thereby greatly improving the integrity of the waterproof barrier. This not only reduces reliance on high-pressure grouting equipment and saves energy costs, but also avoids the risk of rock mass instability caused by blasting or strong hydraulic fracturing, providing a reliable and economical solution for water inrush prevention in deep coal mines.
[0021] In summary, to address the problem of insufficient permeability in the critical water-tight layer 400, which restricts grout diffusion, the method in this embodiment adopts a step-by-step chemical static fracturing strategy. First, the primary fracture network 3 is constructed in the target rock layer by the slow-release expansion of the solid explosive cartridge in borehole 1. Then, the liquid explosive penetrates and expands along the primary fracture network 3 to achieve low-stress directional expansion of the fractures and improve the permeability of the rock mass.
[0022] It should be noted that after the coal seam 100 is mined out, a goaf area 200 is formed. In the overlying strata above the goaf area 200, the water-blocking key layer 400 is located below the aquifer 300. The water-blocking key layer 400 is characterized by its density and low permeability. When the fracture characteristics of the rock strata below the aquifer 300 are monitored using the microseismic monitoring method and it is found that the height of the water-conducting fracture 500 is too large, it is judged that there is a significant risk of water inrush that breaks through the water-blocking key layer 400 and connects the aquifer 300 with the goaf area 200. Therefore, the method of this embodiment is used to reinforce and prevent seepage of the water-blocking key layer 400.
[0023] Microseismic monitoring is a rock mass microfracture monitoring technology developed based on seismic monitoring technology. Its core principle is that rock masses develop microfractures during stress-induced failure. These microfractures release energy in the form of elastic waves (sound waves). Sensors deployed within an effective range receive these signals, and inversion methods are used to determine the time, location, and nature of the rock mass microfractures—the three elements of "time, space, and intensity." The fracture characteristics obtained using microseismic monitoring include: fracture distribution, development height, and connectivity.
[0024] The method in this embodiment uses microseismic monitoring to obtain the fracture characteristics of the rock strata 300 meters below the aquifer, which can provide a targeted positioning basis for seepage prevention reinforcement. Specifically, by using the identification and judgment of fracture characteristics, a target positioning is provided for subsequent reinforcement, effectively avoiding blind construction.
[0025] The fracture zone of the water-proof key layer 400 refers to the area where the fractures with excessive height (water-conducting fractures 500) are located. The borehole 1 extends from the surface to the fracture zone of the water-proof key layer 400. Preferably, the borehole 1 extends to the bottom of the water-proof key layer 400.
[0026] Both the static fracturing solid charge 2 and the static fracturing liquid charge 4 are based on static fracturing agents. Static fracturing technology, which uses physical or chemical means, induces controlled fracturing of rocks or coal under no-power or low-power conditions. Compared with traditional explosive blasting, static fracturing has significant advantages such as no vibration, no flyrock, no dust, and no harmful gases.
[0027] The purpose of arranging multiple static fracturing solid explosive cartridges 2 is to initially induce the formation of a new, interconnected fracture network within the originally dense, low-permeability water-tight key layer 400, thereby increasing the permeability of the rock mass and creating a primary channel for subsequent grout diffusion.
[0028] In some embodiments, the method further includes: After the grout solidifies, the residual cracks in the impermeable zone 6 of the stone body are obtained using the microseismic monitoring method. When the number of residual cracks in the impermeable zone 6 of the stone body is not greater than the preset number, it is determined that the water-proof key layer 400 has been reinforced. When the number of residual fractures in the impermeable zone 6 of the stone body exceeds the preset number, grout is injected into the secondary fracture network 5 again and the injection pressure of the grout is increased so that the grout fills the residual fractures.
[0029] It is understandable that microseismic monitoring is used to evaluate the effectiveness of grouting in the seepage-blocking zone 6 of the rock body, and the reinforcement measures are dynamically adjusted based on the residual fracture distribution data to form a closed-loop quality control, thereby effectively blocking the seepage path from the aquifer 300 to the goaf 200 and improving the coal mine's ability to prevent water inrush.
[0030] It should be noted that when the number of residual fractures in the stone-body seepage-blocking zone 6 is not greater than the preset number, it is judged that there are very few residual fractures and the seepage-blocking effect is good, and the process is declared complete. When the number of residual fractures in the stone-body seepage-blocking zone 6 is greater than the preset number, it is judged that there are many residual fractures and the seepage-blocking effect is not up to standard. Therefore, grout is injected into the secondary fracture network 5 again and the injection pressure of the grout is increased so that the grout fills the residual fractures and achieves optimized reinforcement of the stone-body seepage-blocking zone 6.
[0031] In some embodiments, arranging a plurality of spaced-apart static fracturing solid explosive cartridges 2 at the water-tight critical layer 400 of the borehole 1 includes: Apply adhesive to the wall of borehole 1; Based on a preset spacing, multiple static fracturing solid explosive cartridges 2 are sequentially pushed to the water-tight critical layer 400 of borehole 1.
[0032] It is understandable that an adhesive is placed on the borehole wall of borehole 1 to prevent the static fracturing solid explosive cartridge 2 from slipping off, thereby ensuring the stable placement of the static fracturing solid explosive cartridge 2 in the preset position within borehole 1 and thus ensuring the efficient expansion of the primary fracture network 3.
[0033] In addition, the equidistant arrangement of multiple static fracturing solid cartridges 2 along a preset spacing enables the uniform formation of the initial fracture network 3 within the waterproof key layer 400, thereby ensuring high connectivity of the fracture network.
[0034] It should be noted that the adhesive can be clay. That is, before loading the cartridge, a layer of clay is laid on the inner wall of borehole 1 to prevent the cartridge from slipping off by using the adhesive force of the clay.
[0035] In some embodiments, arranging a plurality of spaced-apart static fracturing solid explosive cartridges 2 at the water-tight critical layer 400 of the borehole 1 includes: Multiple water-immersed and activated static fracturing solid explosive cartridges 2 are spaced apart at the water-proof key layer 400 of borehole 1. Wait for a preset expansion time to allow the statically fractured solid charge 2 to form an initial fracture network 3 using the generated continuous expansion stress.
[0036] It is understandable that the statically fracturing solid explosive cartridge 2, which is activated by water immersion, undergoes a chemical reaction in borehole 1, generating continuous expansion stress that acts on the rock mass surrounding the borehole wall, and after a preset propagation time, the initial fracture network 3 is achieved.
[0037] In some embodiments, the preset spacing ranges from 0.5m to 1.5m.
[0038] In some embodiments, the preset extension time ranges from 24h to 36h.
[0039] Understandably, after 24-36 hours, the static fracturing agent inside the cartridge undergoes a chemical reaction, generating expansion stress. This expansion stress acts on the borehole wall, causing the target rock layer to fracture under the influence of expansion stress. This results in the formation of an initial fracture network 3 within the rock layer, which initially increases the permeability of the target rock layer.
[0040] In some embodiments, injecting a static fracturing liquid agent 4 into the initial fracture network 3 includes: Clean the residue inside borehole 1; The static fracturing liquid agent 4 is injected into the borehole 1 at a first preset pressure and the borehole 1 is sealed so that the static fracturing liquid agent 4 fills the primary fracture network 3. Wait for a preset expansion time so that the static fracturing liquid solution 4 can form a secondary fracture network 5 using the generated continuous expansion stress.
[0041] It is understandable that after the initial fracture network 3 is formed, the residue after the reaction of the static fracturing solid explosive cartridge 2 is cleaned up, so as to facilitate the further formation of the secondary fracture network 5 using the static fracturing liquid explosive solution 4.
[0042] The static fracturing liquid 4 is injected into the cleaned borehole 1 at a first preset pressure, and the borehole opening is sealed. Under pressure, the static fracturing liquid 4 not only fills the borehole 1 but also penetrates deeply into the primary fracture network 3 generated by the initial fracturing. The static fracturing liquid 4 also undergoes a chemical reaction period with a preset propagation time, resulting in a wider and deeper range of expansion stress. This effectively fracturing, propagating, and connecting the primary fractures, inducing a secondary fracturing network system with a larger range, higher density, and better connectivity within the water-impermeable critical layer 400, thus significantly improving the permeability of the rock mass.
[0043] like Figure 3 As shown, in some embodiments, injecting a static fracturing liquid agent 4 into the initial fracture network 3 includes: Use a drilling rig to clean the residue inside borehole 1; The static fracturing liquid agent 4 is injected into the borehole 1 at a first preset pressure using the injection pump 7, and the borehole opening of the borehole 1 is sealed using the liquid agent sealing device 8, so that the static fracturing liquid agent 4 fills the primary fracture network 3.
[0044] It is understandable that by using a drilling rig to clean the residue inside borehole 1, using a liquid injection pump 7 to inject static fracturing liquid agent 4 into borehole 1, and using a liquid agent sealing device 8 to seal the opening of borehole 1, the injection of static fracturing liquid agent 4 and the formation of secondary fracture network 5 are achieved.
[0045] It should be noted that the drilling rig re-drills hole 1 within hole 1 to remove the residue inside hole 1.
[0046] In some embodiments, injecting a static fracturing liquid agent 4 into the initial fracture network 3 includes: The static cracking agent and water are mixed in a preset ratio to form a static cracking liquid solution 4.
[0047] Understandably, by mixing static fracturing agent and water in a certain ratio, a static fracturing liquid solution 4 is achieved, which facilitates the placement of static fracturing agent into the primary fracture network 3, thereby ensuring the steady formation of the secondary fracture network 5.
[0048] It should be noted that the preset ratio can be set according to actual needs, and there are no restrictions on it.
[0049] like Figure 4 As shown, in some embodiments, injecting grout into the secondary fracture network 5 includes: The grout is injected into the borehole 1 at a second preset pressure using the grouting pump 9 and the borehole opening is sealed using the grout sealing device 10 so that the grout fills the secondary fracture network 5. Wait for the preset solidification time to allow the slurry to solidify and form a stone.
[0050] Understandably, after the water-tight key layer 400 undergoes two stages of fracturing to form a highly permeable fracture network, grout is injected into the water-tight key layer 400 through borehole 1. High-pressure grouting pump 9 and grout sealing device 10 are used to ensure grouting pressure and tightness. Thanks to the significantly increased permeability of the rock strata in the early stage, the grout can fully diffuse, penetrate and fill the extensive fracture network formed by the secondary fracturing.
[0051] After the grout solidifies, a stone-body seepage-blocking zone 6 is formed within the key water-blocking layer 400, which is of sufficient range, has good continuity, and significantly enhanced mechanical strength and seepage resistance. This seepage-blocking zone effectively seals the original water-conducting fissures 500 and prevents water from the aquifer 300 from seeping into the goaf 200.
[0052] It should be noted that the preset solidification time can be in the range of 48h-72h.
[0053] In the description of this disclosure, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this disclosure, unless otherwise stated, "a plurality of" means two or more.
[0054] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of preferred embodiments of this disclosure includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the function involved, as will be understood by those skilled in the art to which embodiments of this disclosure pertain.
[0055] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. 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.
[0056] Although embodiments of the present disclosure have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present disclosure. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present disclosure.
Claims
1. A method for reinforcing and preventing seepage in key water-impermeable layers of coal mines based on microseismic monitoring, characterized in that, include: The fracture characteristics of the rock strata below the aquifer are obtained by using microseismic monitoring, wherein the rock strata below the aquifer are located above the goaf and include the water-resistant key layer; When the height of the fractures in the rock strata below the aquifer is greater than the preset height, boreholes are drilled from the surface into the fracture zone of the key water-proof layer. Multiple static fracturing solid explosive cartridges are arranged at intervals at the water-tight critical layer of the borehole. The static fracturing solid explosive cartridges cause the borehole to expand the fractures radially and form an initial fracture network in the water-tight critical layer. A static fracturing liquid solution is injected into the primary fracture network, which causes the primary fracture network to expand fractures and form a secondary fracture network. Grout is injected into the secondary fracture network, and after the grout solidifies, it forms a stone-like impermeable zone in the key waterproof layer.
2. The method for reinforcing and preventing seepage in key water-impermeable layers of coal mines based on microseismic monitoring according to claim 1, characterized in that, The method further includes: After the slurry solidifies, the residual cracks in the impermeable zone of the stone body are obtained using microseismic monitoring. When the number of residual cracks in the impermeable zone of the stone body is not greater than the preset number, it is determined that the water-proof key layer has been reinforced. When the number of residual fractures in the impermeable zone of the stone body exceeds the preset number, grout is injected into the secondary fracture network again and the injection pressure of the grout is increased so that the grout fills the residual fractures.
3. The method for reinforcing and preventing seepage in key water-impermeable layers of coal mines based on microseismic monitoring according to claim 1, characterized in that, The arrangement of multiple spaced-apart static fracturing solid explosive cartridges at the water-tight critical layer of the borehole includes: An adhesive is applied to the borehole wall; Based on a preset spacing, multiple static fracturing solid explosive cartridges are sequentially pushed to the water-tight critical layer of the borehole.
4. The method for reinforcing and preventing seepage in key water-impermeable layers of coal mines based on microseismic monitoring according to claim 1, characterized in that, The arrangement of multiple spaced-apart static fracturing solid explosive cartridges at the water-tight critical layer of the borehole includes: Multiple water-activated static fracturing solid explosive cartridges are spaced apart at the water-tight critical layer of the borehole. A preset extension time is allowed to allow the statically fractured solid charge to form the initial fracture network using the generated continuous expansion stress.
5. The method for reinforcing and preventing seepage in key water-impermeable layers of coal mines based on microseismic monitoring according to claim 1, characterized in that, The preset spacing ranges from 0.5m to 1.5m.
6. The method for reinforcing and preventing seepage in key water-impermeable layers of coal mines based on microseismic monitoring according to claim 1, characterized in that, The preset extension time ranges from 24h to 36h.
7. The method for reinforcing and preventing seepage in key water-impermeable layers of coal mines based on microseismic monitoring according to claim 1, characterized in that, The injection of static fracturing liquid solution into the initial fracture network includes: Clean the residue inside the drill hole; The static fracturing liquid solution is injected into the borehole at a first preset pressure and the borehole opening is sealed so that the static fracturing liquid solution fills the primary fracture network. A preset extension time is allowed to allow the static fracturing liquid solution to form the secondary fracture network using the resulting continuous expansion stress.
8. The method for reinforcing and preventing seepage in key water-impermeable layers of coal mines based on microseismic monitoring according to claim 1, characterized in that, The injection of static fracturing liquid solution into the initial fracture network includes: Use a drilling rig to clean the residue inside the borehole; The static fracturing liquid solution is injected into the borehole at a first preset pressure using an injection pump, and the borehole opening is sealed using a solution sealing device, so that the static fracturing liquid solution fills the primary fracture network.
9. The method for reinforcing and preventing seepage in key water-impermeable layers of coal mines based on microseismic monitoring according to claim 1, characterized in that, The injection of static fracturing liquid solution into the initial fracture network includes: The static cracking agent and water are mixed in a preset ratio to form the static cracking liquid solution.
10. The method for reinforcing and preventing seepage in key water-impermeable layers of coal mines based on microseismic monitoring according to claim 1, characterized in that, The injection of grout into the secondary fracture network includes: The grout is injected into the borehole at a second preset pressure using a grouting pump, and the borehole opening is sealed using a grout sealing device, so that the grout fills the secondary fracture network. Wait for a preset solidification time to allow the slurry to solidify and form a stone.