Mine roof water disaster area advanced exploration treatment method

Abstract

The application discloses a mine roof water disaster area advanced exploration treatment method, and specifically implements the following steps: step 1, determining a roof water disaster area advanced exploration treatment mode; step 2, determining arrangement horizons of roof exploration treatment boreholes and lateral interception boreholes; step 3, determining roof exploration treatment borehole and lateral interception borehole grouting materials; step 4, performing grouting tests to determine roof exploration treatment borehole spacings; step 5, determining roof exploration treatment borehole and lateral interception borehole grouting end pressures; step 6, performing comprehensive exploration of roof water conducting channels; and step 7, performing exploration treatment effect verification. The mine roof water disaster area advanced exploration treatment method can explore and block water conducting channels between roof aquifers and water conducting fractured zones before working face mining, intercept lateral recharge of the aquifer, prevent roof water disaster accidents, and reduce damage of mining to underground water resources.

Description

Technical Field

[0001] This invention belongs to the technical field of mine roof water hazard control methods, and relates to a method for advanced exploration and control of mine roof water hazard areas. Background Technology

[0002] Water hazards in the roof of coal seams are quite common. Over long-term coal mining operations, relatively effective water hazard prevention measures have been developed. The first type is aquifer pre-release, which involves releasing the static reserves in the aquifer before mining to prevent excessive water volume during mining and achieve "peak shaving and valley leveling" of mine water inflow. The second type is sealing the water-conducting fracture zone after mining the working face to cut off the dynamic supply of the aquifer to the goaf and reduce the water volume in the goaf. The third type is adopting methods such as height-limited mining and backfilling mining to reduce the height of the water-conducting fracture zone and prevent it from affecting the roof aquifer.

[0003] Existing technologies have the following drawbacks:

[0004] (i) Pre-drainage of aquifers requires drainage to begin before mining, which is costly and seriously affects the production efficiency of the mine. This method is not applicable to aquifers that are important for water supply or whose drainage may cause surface subsidence.

[0005] (ii) The construction of sealing the water-conducting fracture zone after mining is difficult, the construction technology is not yet mature, the sealing effect cannot be guaranteed, and water inflow during mining cannot be avoided.

[0006] (III) The method of limiting height and backfilling mining to prevent roof water hazards is only applicable to the condition that the roof strata of the coal seam are intact. For areas where there is a vertical water-conducting channel between the water-conducting fracture zone and the roof aquifer, simply reducing the height of the water-conducting fracture zone cannot prevent the occurrence of roof water hazards.

[0007] Therefore, current technology cannot avoid the disturbance of aquifers caused by coal mining. It is necessary to take other measures to fundamentally prevent roof water disasters and reduce the damage of coal mining to groundwater. Summary of the Invention

[0008] The purpose of this invention is to provide a method for advance exploration and treatment of water hazard areas in mine roofs. Before mining, the water-conducting channels between the aquifer and the water-conducting fracture zone in the roof are explored and sealed to intercept the lateral recharge of the aquifer, prevent roof water hazard accidents, and reduce the damage of mining to groundwater resources.

[0009] The technical solution adopted in this invention is a method for advanced exploration and treatment of water hazard areas on the mine roof, which is implemented according to the following steps:

[0010] Step 1: Determine the advanced investigation and treatment model for areas prone to roof water damage;

[0011] Step 2: Determine the strata for the top slab exploration and treatment boreholes and the lateral interception boreholes;

[0012] Step 3: Determine the grouting materials for the roof exploration and treatment boreholes and the lateral interception boreholes;

[0013] Step 4: Conduct grouting tests to determine the spacing of boreholes for roof exploration and treatment;

[0014] Step 5: Determine the grouting end pressure of the top slab exploration and treatment holes and the lateral interception holes;

[0015] Step 6: Comprehensive exploration of the roof slab water diversion channel;

[0016] Step 7: Conduct an investigation to verify the effectiveness of the treatment.

[0017] The invention is further characterized in that,

[0018] The specific advanced exploration and treatment modes for the roof water hazard area in Step 1 are as follows: Mode 1: If an aquifer is expected to develop within the water-conducting fracture zone, then lateral interception treatment of the aquifer will be carried out; Mode 2: If an aquifer is expected to develop above the water-conducting fracture zone, then roof exploration and treatment will be carried out; Mode 3: If an aquifer is expected to develop within the water-conducting fracture zone and an aquifer is expected to develop above the water-conducting fracture zone, then lateral interception treatment of the aquifer and roof exploration and treatment will be carried out simultaneously.

[0019] In step 1, modes 1-3 are all carried out before coal seam mining, that is, before the formation of the water-conducting fracture zone in the roof of the coal seam. The lateral interception treatment of the aquifer and the roof exploration treatment are both carried out by using directional horizontal branch boreholes on the ground to form roof exploration treatment boreholes and lateral interception boreholes. Then, the water-conducting channels at the water-conducting exploration points are sealed by grouting the boreholes.

[0020] In step 2, the stratigraphic positions of the roof exploration and treatment boreholes should be located above the expected water-conducting fracture zone and below the roof aquifer, and the distance c between the roof exploration and treatment boreholes and the expected water-conducting fracture zone should not be less than 3 times the mining height; the distance i between the roof exploration and treatment boreholes and the boundary of the expected water-conducting fracture zone should meet the requirements of Equation 1; if the roof aquifer is a loose porous aquifer, the vertical distance M between the roof exploration and treatment boreholes and the bottom boundary of the loose layer should also be greater than 45m.

[0021] i = 10 * P' (Equation 1)

[0022] i represents the distance between the exploration and treatment borehole in the top plate and the boundary of the expected water-conducting fracture zone, in meters (m). P' represents the maximum water pressure of the aquifer at the location of the exploration and treatment borehole in the top plate over the past three years, in MPa.

[0023] The lateral cutoff borehole arrangement determined in step 2 is located within the aquifer, and the distance h between the planar position of the lateral cutoff borehole and the expected water-conducting fracture zone is the slurry diffusion range. The number of lateral cutoff borehole rows is determined based on the effective width L of the lateral cutoff boreholes.

[0024] L = 10 * P' (Equation 2)

[0025] Where L is the effective width of the lateral interception hole in meters (m), and P' is the maximum water pressure of the aquifer at the lateral interception location in the past three years in MPa.

[0026] In step 3, the grouting material for the lateral interception borehole is cement single-liquid grout with a cement grade of not less than 32.5 and a water-to-solid ratio of 3:1 to 1:1; the grouting material for the top plate exploration and treatment borehole is clay cement grout.

[0027] Step 4 is as follows: Before the grouting test, the boreholes are arranged according to the empirical value of 60m spacing. After the grouting test, the grout diffusion range is determined based on the presence of stones or tracers in the rock cuttings returned during drilling. If the grout diffusion range is greater than 30m, the boreholes are arranged at a spacing of 60m. If the grout diffusion range is less than 30m, the borehole spacing needs to be reduced to twice the actual grout diffusion range.

[0028] Step 5 specifically involves the following: At the end of grouting, the effective pressure P of the grouting layer must be greater than 1.5 times the hydrostatic pressure of the aquifer. Specifically, for roof exploration and treatment, the aquifer at the drilling site is the aquifer above the water-conducting fracture zone of the roof; for lateral interception treatment, the aquifer at the drilling site is the aquifer within the water-conducting fracture zone. The calculation method for the effective pressure P of the grouting layer is as follows:

[0029] P = P k +P j -P g (Equation 3)

[0030] In the formula, P is the effective pressure of the injection layer, MPa; P k P represents the orifice pressure, in MPa. j P represents the effective pressure of the slurry, in MPa. g The resistance of the pipeline and the borehole is expressed in MPa.

[0031] Among them, the effective pressure of the slurry P j The calculation method is as follows:

[0032]

[0033] In the formula, γ is the specific gravity of the slurry; h s h is the vertical distance from the orifice to the stable water level. j The vertical distance between the stabilizing water level after drilling and the deepest point of the lateral interception borehole or the top plate exploration and treatment borehole trajectory.

[0034] Step 6 specifically involves: determining the roof water guiding channel by comprehensively considering the mud consumption during drilling, pressure changes during grouting, and water level changes in the roof aquifer during grouting, and identifying the characteristics of the water guiding channel, including a mud consumption greater than 3m³. 3 / h, sudden pressure drop during grouting, rise in water level of aquifer in the roof during grouting.

[0035] Step 7 specifically involves: In areas requiring roof exploration and treatment drilling, drilling is performed from downhole at an inclined angle to the roof, with the final borehole position not exceeding the roof exploration and treatment layer; alternatively, a vertical borehole is drilled from the surface, with the roof exploration and treatment layer and overlying strata sealed by casing, and the final borehole position below the roof exploration and treatment layer. In areas requiring lateral flow interception, the final borehole position is located within the aquifer requiring lateral flow interception. Verification is then conducted using downhole water release or surface pumping. If the borehole is dry or contains water but quickly depletes, it indicates that the roof sealing or lateral flow interception has achieved its intended purpose.

[0036] The beneficial effects of this invention are as follows: Before mining the working face, this invention uses directional horizontal branch drilling above the water-conducting fracture zone to explore the water-conducting channels in the roof that exist between the roof aquifer and the water-conducting fracture zone. Grouting is then used to seal these channels, and lateral grouting is used to intercept the water flow in the roof aquifer within the influence range of the water-conducting fracture zone. Therefore, it is no longer necessary to pre-drain groundwater before mining the working face, and the water inflow during mining is significantly reduced. Using this method can prevent roof water-related accidents, greatly reduce mine drainage volume and costs, avoid damage to groundwater during coal mining, and achieve the goal of water-conserving coal mining. Attached Figure Description

[0037] Figure 1 This is a flowchart of the method for advanced exploration and treatment of water hazard areas on the mine roof according to the present invention;

[0038] Figure 2 This is a schematic diagram of Mode 1 in the method for advance exploration and treatment of water hazard areas on the mine roof of the present invention;

[0039] Figure 3 This is a schematic diagram of Mode 2 in the method for advance exploration and treatment of water hazard areas on the mine roof of the present invention;

[0040] Figure 4 This is a schematic diagram of Mode 3 in the method for advance exploration and treatment of water hazard areas on the mine roof of the present invention;

[0041] Figure 5 This is a schematic diagram of the aquifer structure in the study area in Embodiment 2 of the present invention;

[0042] Figure 6 This is a schematic diagram of the advanced treatment mode for water damage areas on the roof in Embodiment 2 of the present invention.

[0043] In the figure: a represents the aquifer, b represents the roof exploration and treatment borehole, c represents the distance between the roof exploration and treatment borehole and the expected top boundary of the water-conducting fracture zone, d represents the lateral cutoff borehole, e represents the expected range of the water-conducting fracture zone, f represents the coal seam, g represents the water-conducting channel, h represents the distance between the planar position of the lateral cutoff borehole and the expected water-conducting fracture zone, and i represents the distance between the roof exploration and treatment borehole and the expected boundary of the water-conducting fracture zone. Detailed Implementation

[0044] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0045] Example 1

[0046] The present invention relates to a method for advanced exploration and treatment of water hazard areas in mine roofs, the process of which is as follows: Figure 1 As shown, the specific steps are as follows:

[0047] Step 1: Determine the advanced investigation and treatment model for roof water hazard areas; specifically, the advanced investigation and treatment model for roof water hazard areas is as follows: Figure 2 As shown, Mode 1: If an aquifer a is expected to develop within the water-conducting fracture zone e, then lateral interception and treatment of the aquifer will be carried out; if... Figure 3 As shown, Mode 2: If an aquifer is developed above the water-conducting fracture zone, then roof exploration and remediation should be carried out; if... Figure 4 As shown, Mode 3: If an aquifer is expected to develop within the water-conducting fracture zone and an aquifer is expected to develop above the water-conducting fracture zone, then the aquifer lateral interception treatment and the roof exploration treatment will be carried out simultaneously.

[0048] Modes 1-3 are all carried out before the coal seam f is mined, that is, before the water-conducting fracture zone in the roof of the coal seam is formed. The lateral interception treatment of the aquifer and the roof exploration treatment are both carried out by using directional horizontal branch boreholes on the ground to form roof exploration treatment borehole b and lateral interception borehole d. Then, the water-conducting channel g at the water-conducting exploration point is blocked by grouting the boreholes respectively.

[0049] Step 2: Determine the strata for the top slab exploration and treatment boreholes and the lateral interception boreholes;

[0050] The determined locations of the roof exploration and treatment boreholes are within the strata above the expected water-conducting fracture zone and below the roof aquifer, and the distance c between the roof exploration and treatment boreholes and the expected water-conducting fracture zone is not less than 3 times the mining height; the distance i between the roof exploration and treatment boreholes and the boundary of the expected water-conducting fracture zone should meet the requirements of Equation 1; if the roof aquifer is a loose porous aquifer, the vertical distance M between the roof exploration and treatment boreholes and the bottom boundary of the loose layer must also be greater than 45m.

[0051] i = 10 * P' (Equation 1)

[0052] i represents the distance between the exploration and treatment borehole in the top plate and the boundary of the expected water-conducting fracture zone, in meters (m). P' represents the maximum water pressure of the aquifer at the location of the exploration and treatment borehole in the top plate over the past three years, in MPa.

[0053] The lateral cutoff borehole arrangement determined in step 2 is located within the aquifer, and the distance h between the planar position of the lateral cutoff borehole and the expected water-conducting fracture zone is the slurry diffusion range. The number of lateral cutoff borehole rows is determined based on the effective width L of the lateral cutoff boreholes.

[0054] L = 10 * P' (Equation 2)

[0055] Where L is the effective width of the lateral interception hole in meters, and P' is the maximum water pressure of the aquifer at the lateral interception location in the past three years in MPa.

[0056] Step 3: Determine the grouting materials for the top plate exploration and treatment boreholes and the lateral interception boreholes; the grouting material for the lateral interception boreholes is cement single-liquid grout with a cement grade of not less than 32.5 and a water-to-solid ratio of 3:1 to 1:1; the grouting material for the top plate exploration and treatment boreholes is clay-cement grout.

[0057] Step 4: Conduct grouting tests to determine the spacing of boreholes for roof exploration and treatment. Specifically, before the grouting test, boreholes are arranged according to the empirical value of 60m spacing. After the grouting test, the grout diffusion range is determined based on the presence of stones or tracers in the rock cuttings returned during drilling. If the grout diffusion range is greater than 30m, boreholes are arranged at a spacing of 60m. If the grout diffusion range is less than 30m, the borehole spacing needs to be reduced to twice the actual grout diffusion range.

[0058] Step 5: Determine the grouting completion pressure of the roof exploration and treatment boreholes and the lateral interception boreholes. Specifically, the effective pressure P of the grouting layer at the end of grouting should be greater than 1.5 times the hydrostatic pressure of the aquifer. For roof exploration and treatment, the aquifer above the water-conducting fracture zone of the roof is the aquifer for the lateral interception boreholes. For lateral interception and treatment, the aquifer within the water-conducting fracture zone is the aquifer. The calculation method for the effective pressure P of the grouting layer is as follows:

[0059] P = P k +P j -P g (Equation 3)

[0060] In the formula, P is the effective pressure of the injection layer, MPa; P k P represents the orifice pressure, in MPa. j P represents the effective pressure of the slurry, in MPa. g The resistance of the pipeline and the borehole is expressed in MPa.

[0061] Among them, the effective pressure of the slurry P j The calculation method is as follows:

[0062]

[0063] In the formula, γ is the specific gravity of the slurry; h s h is the vertical distance from the orifice to the stable water level. j The vertical distance between the stabilizing water level after drilling and the deepest point of the lateral interception borehole or the top plate exploration and treatment borehole trajectory.

[0064] Step 6, Comprehensive Investigation of Top Water Conduits; Specifically, this involves determining the top water conduits based on the mud consumption during drilling, pressure changes during grouting, and water level changes in the top aquifer during grouting, and identifying the characteristics of the water conduits, including mud consumption greater than 3m³. 3 / h, sudden pressure drop during grouting, rise in water level of aquifer in the roof during grouting.

[0065] Step 7: Verify the effectiveness of the exploration and treatment. Specifically: In areas requiring roof exploration and treatment drilling, drill inclined roof holes from the well, with the final hole position not exceeding the roof exploration and treatment layer; or drill vertical holes from the surface, sealing the roof exploration and treatment layer and overlying strata with casing, with the final hole position below the roof exploration and treatment layer. In areas requiring lateral flow interception, the final hole position is located within the aquifer requiring lateral flow interception. Then, verify the effectiveness by draining water from the well or pumping water from the surface. If there is no water in the borehole or water is present but quickly diminishes to no water, it indicates that the roof sealing or lateral flow interception has achieved the expected goal.

[0066] Example 2

[0067] Based on Example 1, in step 2, the slurry diffusion range is set at 20m, and the distance h between the lateral cutoff borehole plane position and the expected water-conducting fracture zone is 20m.

[0068] Example 3

[0069] Step 1: Determine the advanced investigation and treatment model for areas prone to roof water damage.

[0070] like Figure 5 As shown, the coal seam thickness in the study area is 6m, the expected height of the water-conducting fracture zone is 100m, an aquifer 2 is developed within the water-conducting fracture zone, and an aquifer 1 is developed 30m above the water-conducting fracture zone. Drilling verification shows that there is a vertical water-conducting channel between aquifer 1 and the expected water-conducting fracture zone. In order to avoid roof water hazard accidents during mining, it is necessary to carry out advance treatment of the roof water hazard area. According to the invention, the advance exploration and treatment mode of the roof water hazard area is determined to be mode 3, which requires simultaneous aquifer lateral interception treatment and roof exploration treatment.

[0071] Step 2: Determine the strata for the top slab exploration and treatment boreholes and the lateral cutoff boreholes.

[0072] like Figure 6 As shown, the top exploration and treatment boreholes are located in the stratum above the expected water-conducting fracture zone and below the top aquifer 1. The distance between the top exploration and treatment boreholes and the top boundary of the expected water-conducting fracture zone is 3 times the coal thickness, i.e., 18m. The water pressure of the aquifer at the top exploration and treatment borehole is 5.8MPa, and the distance between the top exploration and treatment borehole and the boundary of the expected water-conducting fracture zone is 58m. The lateral interception boreholes are located in the stratum 2. The slurry diffusion range is calculated as 20m. The distance between the lateral interception borehole plane position and the expected water-conducting fracture zone is 20m. The maximum water pressure of the aquifer at the lateral interception location in the past three years is 6MPa. Considering that the effective thickness of the diffusion range on both sides should not be less than 60m, two rows of lateral interception boreholes need to be arranged.

[0073] Step 3: Determine the grouting materials for the roof exploration and treatment boreholes and the lateral cutoff boreholes.

[0074] The lateral cutoff borehole uses single-liquid cement grout. The cement is fly ash cement produced by a cement plant near the study area, grade 32.5. The water-to-solid ratio during grouting ranges from 3:1 to 1:1, with the water-cement ratio gradually decreasing. The roof exploration and treatment layer will deform due to mining, so it needs to have a certain degree of flexibility. Clay cement grout is used, with the clay taken from local surface clay. The cement is the same as that used for the lateral cutoff borehole.

[0075] Step 4: Conduct grouting tests to determine the spacing of boreholes for roof exploration and treatment.

[0076] The boreholes were arranged according to the empirical value of 60m spacing. After the grouting test, it was determined that the grout diffusion range was greater than 30m based on the stone content in the rock cuttings returned during drilling and the tracer content. Therefore, the boreholes in the later construction were arranged at a spacing of 60m.

[0077] Step 5: Determine the grouting completion pressure of the top slab exploration and treatment holes and the lateral interception holes.

[0078] Taking hole D1-1 as an example, after the branch hole is pulled out, the stable water level at the hole opening is 600m vertically from the deepest point of the directional hole trajectory. The hydrostatic pressure of the aquifer is 6MPa. At the end of grouting, the effective pressure of the grouting layer should be greater than 1.5 times the hydrostatic pressure of the designed aquifer, which is 9MPa. The hole opening pressure at the end of grouting under various grout specific gravity conditions is calculated as follows:

[0079] Table 1. Grouting end pressure under different grout specific gravities.

[0080] Orifice pressure at the end of grouting (MPa) 7.8 7.26 5.94

[0081] Step 6: Comprehensive exploration of the roof slab water diversion channel

[0082] Based on the comprehensive analysis of drilling mud consumption, pressure changes during grouting, and water level changes in the roof aquifer during grouting, it was found that mud consumption exceeded 3m³. 3There are 4 borehole sections with pressure drop during grouting, 2 borehole sections with water level rise in the aquifer on the top plate during grouting, and 4 borehole sections with water level rise in the aquifer on the top plate during grouting. It is determined that there is a vertical water-guiding channel of aquifer 1 at the rising borehole section, and it needs to be grouted and sealed.

[0083] Step 7: Conduct investigation and verification of the treatment effect.

[0084] After grouting, verification boreholes were drilled in the underground tunnel using the drilling site to check the roof. During water release, the water volume decreased significantly. However, no significant water level drop was observed in the observation holes outside aquifer 1 and aquifer 2 during water release. This indicates that the roof exploration and treatment project effectively cut off the vertical water-conducting channel between the water-conducting fracture zone and aquifer 1, and effectively implemented curtain closure for aquifer 2. The working face has been safely tested, with a water inflow of 5–8 m³ / h during the test. 3 / h, the advanced treatment project for water damage in the roof area has achieved remarkable results.

Claims

1. A method for advanced investigation and treatment of water hazard areas in mine roofs, characterized in that, The specific steps are as follows: Step 1: Determine the advanced exploration and treatment model for the roof water hazard area, specifically: Model 1: If an aquifer is expected to develop within the water-conducting fracture zone, then implement lateral interception treatment of the aquifer; Model 2: If an aquifer is expected to develop above the water-conducting fracture zone, then implement roof exploration and treatment; Model 3: If an aquifer is expected to develop within both the water-conducting fracture zone and above the water-conducting fracture zone, then implement both lateral interception treatment of the aquifer and roof exploration and treatment simultaneously. Step 2: Determine the strata for the top slab exploration and treatment boreholes and the lateral interception boreholes; Specifically, the determined locations of the roof exploration and treatment boreholes are within the layers above the expected water-conducting fracture zone and below the roof aquifer, and the distance c between the roof exploration and treatment boreholes and the expected water-conducting fracture zone is not less than 3 times the mining height; the distance i between the roof exploration and treatment boreholes and the boundary of the expected water-conducting fracture zone should meet the requirements of Equation 1; if the roof aquifer is a loose porous aquifer, then the vertical distance M between the roof exploration and treatment boreholes and the bottom boundary of the loose layer must also be greater than 45m. i=10 P ， (Equation 1) Where i is the distance between the exploration and treatment borehole in the top plate and the boundary of the expected water-conducting fracture zone, in meters; P is the maximum water pressure of the aquifer at the location of the exploration and treatment borehole in the top plate in the past three years, in MPa. The determined lateral cutoff borehole layout is located within the aquifer, and the distance h between the lateral cutoff borehole planar position and the expected water-conducting fracture zone is the slurry diffusion range, based on the effective width of the lateral cutoff borehole. L Determine the number of rows of lateral flow interceptors: L=10 P ， (Equation 2) in, L The effective width of the lateral interceptor orifice, in meters (m). P ， The maximum water pressure of the aquifer at the lateral interception location over the past three years is expressed in MPa. Step 3: Determine the grouting materials for the roof exploration and treatment boreholes and the lateral interception boreholes; Step 4: Conduct grouting tests to determine the spacing of boreholes for roof exploration and treatment; Step 5: Determine the grouting end pressure of the top slab exploration and treatment holes and the lateral interception holes; Step 6: Comprehensive exploration of the roof slab water diversion channel; Step 7: Conduct an investigation to verify the effectiveness of the treatment.

2. The method for advanced exploration and treatment of mine roof water hazard areas according to claim 1, characterized in that, In step 1, modes 1-3 are all carried out before coal seam mining, that is, before the formation of the water-conducting fracture zone in the roof of the coal seam. The aquifer lateral interception treatment and roof exploration treatment are both carried out by using directional horizontal branch boreholes on the ground to form roof exploration treatment boreholes and lateral interception boreholes. Then, the water-conducting channels at the water-conducting exploration points are blocked by grouting the boreholes.

3. The method for advanced exploration and treatment of mine roof water hazard areas according to claim 1, characterized in that, In step 3, the grouting material for the lateral interception borehole is cement single-liquid grout with a cement grade of not less than 32.5 and a water-to-solid ratio of 3:1 to 1:1; the grouting material for the roof exploration and treatment borehole is clay cement grout.

4. The method for advanced exploration and treatment of mine roof water hazard areas according to claim 1, characterized in that, Step 4 specifically involves: before the grouting test, drilling holes are arranged according to the empirical value of 60m spacing. After the grouting test, the grout diffusion range is determined based on the presence of stones or tracers in the rock cuttings returned during drilling. If the grout diffusion range is greater than 30m, holes are arranged at a spacing of 60m. If the grout diffusion range is less than 30m, the drilling hole spacing needs to be reduced to twice the actual grout diffusion range.

5. The method for advanced exploration and treatment of mine roof water hazard areas according to claim 1, characterized in that, Step 5 specifically involves the following: at the end of grouting, the effective pressure P of the grouting layer is greater than 1.5 times the hydrostatic pressure of the aquifer. Specifically, during roof exploration and treatment, the aquifer at the drilling site for roof exploration and treatment is the aquifer above the water-conducting fracture zone of the roof; during lateral interception treatment of the aquifer, the aquifer at the drilling site for lateral interception is the aquifer within the water-conducting fracture zone. The calculation method for the effective pressure P of the grouting layer is as follows: (Equation 3) In the formula, P is the effective pressure of the injection layer, in MPa; k P represents the orifice pressure, measured in MPa. j P represents the effective pressure of the slurry, in MPa. g The resistance of the pipeline and its borehole is expressed in MPa. Among them, the effective pressure of the slurry P j The calculation method is as follows: (Equation 4) In the formula, Specific gravity of the slurry; h s h is the vertical distance from the orifice to the stable water level. j The vertical distance between the stabilizing water level after drilling and the deepest point of the lateral interception borehole or the top plate exploration and treatment borehole trajectory.

6. The method for advanced exploration and treatment of mine roof water hazard areas according to claim 1, characterized in that, Step 6 specifically involves: determining the roof water guiding channel by comprehensively considering the mud consumption during drilling, pressure changes during grouting, and water level changes in the roof aquifer during grouting, and identifying the characteristics of the water guiding channel, including mud consumption greater than 3m³. 3 / h, sudden pressure drop during grouting, rise in water level of aquifer in the roof during grouting.

7. The method for advanced exploration and treatment of mine roof water hazard areas according to claim 1, characterized in that, Step 7 specifically involves: in areas requiring roof exploration and treatment drilling, drilling is performed from the wellhead at an inclined angle, with the final hole position not exceeding the roof exploration and treatment layer; or, vertical holes are drilled from the surface, with the roof exploration and treatment layer and overlying strata sealed by casing, and the final hole position below the roof exploration and treatment layer; in areas requiring lateral flow interception, the final hole position is located within the aquifer requiring lateral flow interception; subsequently, verification is performed by downhole water release or surface pumping. If there is no water in the borehole or water initially present but quickly diminishes to no water, it indicates that the roof sealing or lateral flow interception has achieved the expected goal.

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