Water draining and pressure reducing method for confined water of coal mine bottom plate
By obtaining the mining parameters of the coal mining working face and implementing the bottom plate water drainage drilling project, the problems of high cost, affecting the ecological environment and low efficiency of the traditional coal mine base plate pressure water, achieving low cost, high efficiency and green environmental protection hydrophobic pressure reduction effects.
Patent Information
- Application Number
- CN202411863867.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-17
- Publication Date
- 2025-03-21
AI Technical Summary
The traditional coal mine base plate pressure-bearing water hydrophobic pressure reduction method has problems such as high cost, affecting the ecological environment and low efficiency.
By obtaining the mining parameters of the coal mining working face, determining the parameters of the bottom plate water drainage drilling, and implementing the bottom plate water drainage drilling project, controlling the drilling valve to achieve a stable water level state, thereby guiding coal mining and hydrophobic pressure reduction.
The cost and engineering volume of hydrophobic pressure reduction are reduced, the efficiency of hydrophobic pressure reduction is improved, the impact on water resources and ecological environment is reduced, and the goal of green and environmental protection is achieved.
Smart Images
Figure CN119664431A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of mining engineering technology, and in particular to a method for draining and reducing the pressure of pressurized water on a coal mine floor. Background Art
[0002] Coal mine flood is one of the five major disasters in coal mines. Prevention and control of coal mine flood is of great significance to the safe production of coal mines. The traditional method of preventing and controlling coal mine floor pressure water disasters is usually to arrange a large number of floor drainage holes outside the coal mining face for full water discharge, but this method has the following problems:
[0003] 1) The amount of water discharged from the bottom plate is too large, resulting in high drainage costs.
[0004] 2) A large amount of drainage water will affect water resources and the ecological environment, which is not conducive to green environmental protection.
[0005] 3) A large amount of water drainage results in a large amount of engineering work, a long construction period and a heavy task, resulting in low efficiency of drainage and pressure reduction.
[0006] Based on this, how to provide a low-cost, green, environmentally friendly and efficient method for draining and reducing the pressure of pressurized water in the bottom slab of a coal mine has become a technical problem that needs to be solved urgently in this field. Summary of the invention
[0007] The purpose of this application is to provide a method for draining and reducing the pressure of pressurized water in a coal mine floor, which can reduce the cost of draining and reducing the pressure, improve the efficiency of draining and reducing the pressure, and is more environmentally friendly.
[0008] To achieve the above objectives, this application provides the following solutions:
[0009] The present application provides a method for draining and reducing the pressure of pressurized water on a coal mine floor, and the method comprises the following steps:
[0010] Obtain mining parameters of coal mining face.
[0011] The bottom plate drainage drilling parameters are determined according to the mining parameters.
[0012] According to the bottom plate drainage drilling parameters, a bottom plate drainage drilling project is implemented in each coal mining section of the coal mining face; the bottom plate drainage drilling project includes drilling holes in the coal seam bottom plate to form a number of bottom plate drainage drilling holes, installing bottom plate drainage drilling valves, and installing bottom plate drainage drilling water-stopping sleeves and flower pipes, wherein the bottom plate drainage drilling valves are used to control the open or closed state of the bottom plate drainage drilling holes, and during the implementation of the bottom plate drainage drilling project, the bottom plate drainage drilling valves remain in a closed state; the bottom plate drainage drilling water-stopping sleeves and flower pipes are used to converge the drainage water of the bottom plate pressurized aquifer to the inside of the bottom plate drainage drilling holes when the bottom plate drainage drilling valves are in an open state.
[0013] Based on the bottom plate drainage drilling project, the bottom plate pressure aquifer in the current coal mining area is drained, and the time when the water level in the bottom plate drainage drilling hole reaches a stable water level state is determined; the time when the water level in the bottom plate drainage drilling hole reaches a stable water level state refers to the time required for the drainage water of the bottom plate pressure aquifer to start flowing into the bottom plate drainage drilling hole after the bottom plate drainage drilling hole valve is opened, until the water level change of the drainage water inside the bottom plate drainage drilling hole within a period of time is less than a threshold.
[0014] According to the time when the water level in the bottom plate drainage borehole reaches a stable water level state, coal mining is carried out in each coal mining section of the coal mining working face.
[0015] Optionally, obtaining mining parameters of the coal mining face specifically includes the following steps:
[0016] According to the borehole histogram, the numerical simulation method is used to simulate the mining process of the coal mining face and obtain the mining parameters of the coal mining face.
[0017] Optionally, the mining parameters include the location of the pressure point of the coal mining face, the interval time of the pressure on the coal mining face, the damage range in the inclination direction of the coal mining face, the damage depth of the bottom plate of the coal mining face and the location of the bottom plate pressure aquifer; wherein, the damage range in the inclination direction of the coal mining face refers to the distance of the mining cracks extending outward along the inclination of the coal mining face, and the damage depth of the bottom plate of the coal mining face refers to the vertical distance between the coal mining face and the deepest fractured rock.
[0018] Optionally, the bottom plate drainage water drilling parameters include the bottom plate drainage water drilling plane position, the bottom plate drainage water drilling diameter change point depth, the bottom plate drainage water drilling end hole position, the bottom plate drainage water drilling water stop casing and flower pipe position and the number of drilling holes arranged at each pressure point.
[0019] Optionally, determining the bottom plate drainage drilling parameters according to the mining parameters specifically includes the following steps:
[0020] According to the position of the pressure point of the coal mining working face, the plane position of the bottom plate water drainage drilling hole is determined.
[0021] The depth of the diameter change point of the bottom plate water drainage drilling hole is determined according to the damage depth of the bottom plate of the coal mining working face.
[0022] The final hole position of the bottom plate water drainage drilling hole is determined according to the position of the bottom plate pressure aquifer.
[0023] The positions of the water-stopping casing and the flower pipe of the bottom plate water drainage drilling hole are determined according to the position of the bottom plate pressure-bearing layer and the depth of the diameter-changing point of the bottom plate water drainage drilling hole.
[0024] The number of drill holes arranged at each pressure point is determined according to the positions of the water-stopping casing and the flower pipe of the bottom plate drainage drilling hole and the positions of the pressure points of the coal mining working face.
[0025] Optionally, based on the floor drainage drilling project, drainage is performed on the floor pressure aquifer in the current coal mining area, and the time when the water level in the floor drainage drilling reaches a stable water level state is determined, which specifically includes the following steps:
[0026] Based on the bottom plate drainage drilling project, the bottom plate pressure aquifer in the current coal mining area is drained, and the drainage time and the water level change in the bottom plate drainage drilling hole are recorded at a preset frequency.
[0027] The time when the water level in the bottom plate drainage borehole reaches a stable water level state is determined according to the drainage time, the water level change in the bottom plate drainage borehole and the threshold.
[0028] Optionally, the threshold is 0.1.
[0029] Optionally, according to the time when the water level in the bottom plate drainage borehole reaches a stable water level state, coal mining is carried out in each coal mining section of the coal mining working face, specifically including the following steps:
[0030] The bottom plate drainage water drilling hole valve control strategy is determined based on the relationship between the time when the water level in the bottom plate drainage water drilling hole reaches a stable water level state and the pressure interval time of the coal mining working face; the bottom plate drainage water drilling hole valve control strategy refers to a strategy for controlling the open or closed state of the bottom plate drainage water drilling hole valve corresponding to the bottom plate drainage water drilling hole during coal mining.
[0031] According to the bottom plate drainage drilling valve control strategy, coal mining is carried out in each coal mining section of the coal mining working face.
[0032] Optionally, the bottom plate drainage drilling valve control strategy includes the following contents:
[0033] When the time it takes for the water level in the bottom plate drainage borehole to reach a stable water level state is less than or equal to the pressure interval time of the coal mining face, the bottom plate drainage borehole valve corresponding to the bottom plate drainage borehole outside the current coal mining area will not be opened.
[0034] When the time it takes for the water level in the bottom plate drainage borehole to reach a stable water level is greater than the interval time of pressure from the coal mining face, the time difference between the time it takes for the water level in the bottom plate drainage borehole to reach a stable water level and the interval time of pressure from the coal mining face is calculated, and the bottom plate drainage borehole valve corresponding to the bottom plate drainage borehole outside the current coal mining area is opened in advance at a time equal to the time difference.
[0035] According to the specific embodiments provided in this application, this application discloses the following technical effects:
[0036] The present application provides a method for draining and reducing the pressure of pressurized water in the floor of a coal mine. The method determines the parameters of floor drainage drilling holes by acquiring the mining parameters of a coal mining face, and implements floor drainage drilling projects in various coal mining sections of the coal mining face. After the completion of the floor drainage drilling project, the floor pressure aquifer of the current coal mining section can be drained, thereby determining the time when the water level in the floor drainage drilling hole of the current coal mining section reaches a stable water level state. The time can be used as basic data to guide the control of floor drainage drilling valves, drainage and pressure reduction, and coal mining in various coal mining sections, thereby facilitating the completion of coal mining in various coal mining sections of the coal mining face. This application only requires drainage and pressure reduction in the current coal mining area, that is, the area where mining is being disturbed, and determines the time when the water level in the bottom plate drainage borehole reaches a stable water level state, so as to guide the various coal mining areas of the coal mining face to quickly and efficiently carry out drainage and pressure reduction and coal mining. It is not only simple and easy to implement, but also can reduce the overall drainage volume, reduce the cost of drainage and pressure reduction, shorten the drainage and pressure reduction period, reduce the amount of engineering, improve the efficiency of drainage and pressure reduction, and is more green and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS
[0037] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0038] Figure 1 A schematic flow chart of a method for draining and reducing the pressure of pressurized water in a coal mine floor provided in one embodiment of the present application.
[0039] Figure 2A schematic diagram of a method for draining and reducing the pressure of pressurized water in a coal mine floor provided in one embodiment of the present application. DETAILED DESCRIPTION
[0040] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.
[0041] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.
[0042] like Figure 1 As shown, this embodiment proposes a method for draining and reducing the pressure of pressurized water on the floor of a coal mine, and the method for draining and reducing the pressure of pressurized water on the floor of a coal mine comprises the following steps:
[0043] Step S1, obtaining mining parameters of the coal mining face.
[0044] In this embodiment, step S1 obtains the mining parameters of the coal mining face, which specifically includes the following steps:
[0045] According to the borehole histogram, the numerical simulation method is used to simulate the mining process of the coal mining face and obtain the mining parameters of the coal mining face.
[0046] In this embodiment, the mining parameters include the location of the pressure point of the coal mining face, the interval time of the pressure of the coal mining face, the damage range of the coal mining face in the inclination direction, the damage depth of the bottom plate of the coal mining face, and the location of the bottom plate pressure-bearing aquifer. Among them, the damage range of the coal mining face in the inclination direction refers to the distance z of the mining crack extending outward along the inclination of the coal mining face, which is measured on the ground and calculated according to the coordinates. The damage depth of the bottom plate of the coal mining face refers to the vertical distance d between the coal mining face and the deepest fractured rock.
[0047] In this embodiment, the borehole histogram is an engineering geological map compiled to describe the layering, thickness, lithology, structural structure and contact relationship of the rock layer, groundwater sampling and testing, borehole structure and drilling, etc. of the borehole, and is an important basis for analyzing engineering geological conditions and drawing geological cross-sections. As a basic tool for visualizing underground exploration information, the borehole histogram plays an important role in the analysis and decision-making of various projects.
[0048] In this embodiment, the steps of the numerical simulation method mainly include the following steps: (1) constructing a numerical model through geological data; (2) obtaining a simulated mining method through mining design; (3) simulating the pressure step distance according to the simulated mining method, wherein each step distance corresponds to a pressure point; (4) calculating the pressure interval time y of the coal mining face according to the pressure step distance obtained by simulation. Among them, the pressure step distance divided by the mining speed is equal to the pressure interval time y of the coal mining face.
[0049] Step S2: Determine the bottom plate drainage drilling parameters according to the mining parameters.
[0050] In this embodiment, step S2 determines the bottom plate drainage drilling parameters according to the mining parameters, and specifically includes the following steps:
[0051] Step S21, determining the plane position of the bottom plate drainage drilling hole according to the pressure point position of the coal mining working face.
[0052] Step S22, determining the depth of the diameter change point of the bottom plate water drainage drilling hole according to the damage depth of the bottom plate of the coal mining working face.
[0053] Step S23, determining the final hole position of the bottom plate water drainage drilling hole according to the position of the bottom plate pressure aquifer.
[0054] Step S24, determining the positions of the water-stopping casing and the flower pipe of the bottom plate water drainage drilling hole according to the position of the bottom plate pressure-bearing layer and the depth of the diameter-changing point of the bottom plate water drainage drilling hole.
[0055] Step S25, determining the number of drill holes arranged at each pressure point according to the positions of the water stop casing and the flower pipe of the bottom plate drainage drilling hole and the positions of the pressure points of the coal mining working face.
[0056] In this embodiment, the bottom plate water drainage drilling parameters include the plane position of the bottom plate water drainage drilling hole, the depth of the bottom plate water drainage drilling hole change point, the end hole position of the bottom plate water drainage drilling hole, the position of the bottom plate water drainage drilling hole water stop casing and flower pipe, and the number of drilling holes arranged at each pressure point.
[0057] In this embodiment, the method for determining the parameters of each bottom plate drainage drilling hole is as follows:
[0058] Bottom plate drainage drilling hole plane position: Take the coal mining face pressure point position determined in step S1 as the origin, extend the position corresponding to the preset distance outside the coal mining face along the inclination direction of the coal mining face, and the position is symmetrically distributed along the center line of the coal mining face, then use this position as the bottom plate drainage drilling hole plane position. In other words, take the coal mining face pressure point position as the origin, and push the position of the mining fissure distance z plus 3 to 5 meters to the coal mining face along the inclination direction of the coal mining face, and symmetrically distribute along the center line of the coal mining face, so as to determine the bottom plate drainage drilling hole plane position.
[0059] Depth of the variable diameter point of the bottom plate drainage drilling hole: The bottom plate drainage drilling hole adopts variable diameter drilling, and the drilling variable diameter point is set at a position 3 to 5 meters downward from the bottom plate damage depth determined in step S1, that is, the vertical distance d. A bottom plate drainage drilling hole valve is set below the drilling hole variable diameter point to control the opening or closing state of the bottom plate drainage drilling hole. The bottom plate drainage drilling hole can be drained by opening the bottom plate drainage drilling hole valve, and the bottom plate drainage drilling hole can be stopped by closing the bottom plate drainage drilling hole valve.
[0060] Final hole position of bottom plate water drainage drilling hole: The final hole position of bottom plate water drainage drilling hole is set at the bottom plate of the bottom plate pressure aquifer to be discharged or at a position more than 10 meters into the bottom plate pressure aquifer to be discharged.
[0061] Design of the position of the water-stopping sleeve and the flower pipe of the bottom plate drainage borehole: A conventional water-stopping sleeve is set above the borehole diameter change point of the bottom plate drainage borehole for sealing and water-stopping of the bottom plate drainage borehole. Another water-stopping sleeve is set below the borehole diameter change point of the bottom plate drainage borehole, and the water-stopping sleeve goes down to the top plate of the bottom plate pressure-bearing aquifer to be discharged, and seals and stops water. Among them, the position of the bottom plate pressure-bearing aquifer is obtained through the borehole bar chart). A variable flower pipe is set in the section of the bottom plate pressure-bearing aquifer to be discharged. The variable flower pipe refers to a flower pipe that can freely adjust the circumferential water inlet direction, that is, a flower pipe that can arbitrarily adjust a certain direction section to have water or no water inlet within the range of 0 to 360°. The flower pipe allows the drainage water of the bottom plate pressure-bearing aquifer to enter the inside of the bottom plate drainage borehole from different directions, and then be discharged to the coal mining face.
[0062] The number of drill holes arranged at each pressure point: actually refers to the number of bottom plate drainage drill holes that need to be set at each pressure point. The number of drill holes arranged at each pressure point is obtained by numerical simulation method. First, a model is established according to the hydrogeological conditions and mining geological conditions of the coal mining face (based on the drill hole bar chart, the model is constructed using numerical simulation software), and then the coal mining face is divided into multiple coal mining blocks along the inclination direction of the coal mining face according to the pressure point position determined in step S1, and then a different number of bottom plate drainage drill holes are set on the boundary of each coal mining block range, and the variable flower pipe of each bottom plate drainage drill hole is closed when one-quarter of the water-passing direction of the coal mining face is drained, and finally the stable water level state in the coal mining block is below the safe mining water level. Among them, the safe mining water level is calculated based on the conventional water inrush coefficient theory.
[0063] Step S3, according to the bottom plate drainage drilling parameters, implement the bottom plate drainage drilling project in each coal mining section of the coal mining working face, and keep the bottom plate drainage drilling valve closed.
[0064] In this embodiment, the bottom plate drainage drilling project includes drilling a plurality of bottom plate drainage drilling holes on the coal seam bottom plate, installing bottom plate drainage drilling hole valves, and installing bottom plate drainage drilling hole water stop sleeves and flower pipes, etc. Among them, the bottom plate drainage drilling hole valve is used to control the open or closed state of the bottom plate drainage drilling hole, and during the implementation of the bottom plate drainage drilling project, the bottom plate drainage drilling hole valve remains in a closed state; the bottom plate drainage drilling hole water stop sleeve and flower pipe are used to converge the drainage water of the bottom plate pressure-bearing aquifer to the inside of the bottom plate drainage drilling hole when the bottom plate drainage drilling hole valve is in an open state.
[0065] Step S4: based on the bottom plate drainage drilling project, drain water from the bottom plate pressure aquifer in the current coal mining area, and determine the time when the water level in the bottom plate drainage drilling hole reaches a stable water level state.
[0066] In this embodiment, the time for the water level in the bottom plate drainage borehole to reach a stable water level state refers to the time required for the drainage water from the bottom plate pressurized aquifer to start flowing into the bottom plate drainage borehole after the bottom plate drainage borehole valve is opened, until the water level change of the drainage water inside the bottom plate drainage borehole over a period of time is less than a threshold.
[0067] In this embodiment, step S4 is based on the floor drainage drilling project to drain water from the floor pressure aquifer in the current coal mining area, and determines the time when the water level in the floor drainage drilling reaches a stable water level state, which specifically includes the following steps:
[0068] Step S41, based on the bottom plate drainage drilling project, drain the bottom plate pressure aquifer in the current coal mining area, and record the drainage time and the water level change in the bottom plate drainage drilling hole according to a preset frequency.
[0069] Step S42, determining the time when the water level in the bottom plate drainage borehole reaches a stable water level state according to the drainage time, the water level change in the bottom plate drainage borehole and the threshold value.
[0070] In this embodiment, when the time x when the water level in the bottom plate drainage borehole reaches the stable water level is measured, the bottom plate drainage borehole valve is opened, and water can be allowed to flow into all directions (0-360° range) of the bottom plate drainage borehole, and then the water level of the bottom plate drainage borehole is recorded every half an hour until the water level change is less than 0.1m or the change amplitude is less than 3% for three consecutive times, and then the bottom plate drainage borehole valve is closed to stop draining water. The last time is recorded as the time x when the water level in the bottom plate drainage borehole reaches the stable water level.
[0071] Step S5, according to the time when the water level in the bottom plate drainage borehole reaches a stable water level state, coal mining is carried out in each coal mining section of the coal mining working face.
[0072] In this embodiment, step S5 performs coal mining on each coal mining section of the coal mining working face according to the time when the water level in the bottom plate drainage borehole reaches a stable water level state, and specifically includes the following steps:
[0073] Step S51, determining the bottom plate drainage water drilling hole valve control strategy according to the relationship between the time x when the water level in the bottom plate drainage water drilling hole reaches a stable water level state and the pressure interval time y of the coal mining working face; the bottom plate drainage water drilling hole valve control strategy refers to a strategy for controlling the open or closed state of the bottom plate drainage water drilling hole valve corresponding to the bottom plate drainage water drilling hole during coal mining.
[0074] In this embodiment, the bottom plate drainage drilling valve control strategy includes the following contents:
[0075] (1) When the time x when the water level in the bottom plate drainage borehole reaches a stable water level state is less than or equal to the pressure interval time y of the coal mining working face, the bottom plate drainage borehole valve corresponding to the bottom plate drainage borehole outside the current coal mining area will not be opened.
[0076] (2) When the time x for the water level in the floor drainage borehole to reach the stable water level state is greater than the interval time y between the weighting of the coal mining face, calculate the time difference between the time x for the water level in the floor drainage borehole to reach the stable water level state and the interval time y between the weighting of the coal mining face, and open the floor drainage borehole valve corresponding to the floor drainage borehole outside the current coal mining section in advance by a time equal to the time difference.
[0077] Step S52: According to the floor drainage borehole valve control strategy, carry out coal mining in each coal mining section of the coal mining face.
[0078] In this embodiment, coal mining is carried out in each coal mining block divided in step S2. In the coal mining block, the floor drainage boreholes within the boundary range are opened to drain water by opening the floor drainage borehole valves, and the quarter water passing direction of the block section facing away from the coal mining face is closed. Here, "facing away" refers to the area with the farthest horizontal distance from the center of the coal mining face, and "facing" refers to the area with the closest horizontal distance from the center of the coal mining face. If y≥x, the floor drainage boreholes outside the current coal mining block do not open the floor drainage borehole valves. If y<x, the floor drainage borehole valves outside the current coal mining block are opened in advance by x - y time, where y is the interval time between the weighting of the coal mining face and x is the time for the water level in the floor drainage borehole to reach the stable water level state. After coal mining has pushed through the corresponding coal mining section, the floor drainage borehole valves within the coal mining section are closed, and the coal mining task of the coal mining face is safely completed under the condition of hydrophobic pressure reduction.
[0079] Traditional hydrophobic pressure reduction methods usually arrange a large number of floor drainage boreholes around the coal mining face for full - volume water drainage, which forms a drawdown curve of a typical pumping well centered on the coal mining face, resulting in a significant drop in the groundwater level of the surrounding area. Based on the theory of water inrush from the floor of the coal mining face (the drainage volume suddenly increases exponentially in a short period), this embodiment determines that due to the transfer of overlying pressure, the area covered by coal mining does not need to be subjected to hydrophobic pressure reduction. Therefore, only the area being disturbed during the mining process needs to be subjected to hydrophobic pressure reduction. Based on the weighting point of the coal mining face, this hydrophobic pressure reduction method can reduce the drainage volume. Moreover, this embodiment designs the water drainage of the circumferential non - complete well in the floor confined aquifer, forming an atypical symmetric drawdown curve, making the water level drop smaller in the area facing away from the coal mining face, thereby effectively reducing the water resource drainage volume, further reducing the drainage cost and workload, shortening the drainage cycle, reducing the impact on the ecological environment, and being conducive to green environmental protection. In summary, compared with the traditional hydrophobic pressure reduction method, the coal mine floor confined water hydrophobic pressure reduction method proposed in this embodiment is not only simple and easy to implement, but also has lower energy consumption, better hydrophobic pressure reduction effect, and is more green and environmentally friendly.
[0080] In order to make the technical solution of this embodiment clearer, the specific implementation process of the technical solution of this embodiment is described in detail below in the form of examples.
[0081] Assume that a coal mine is mining 10 coal seams and is threatened by the underlying confined aquifer, so it needs to drain and reduce the pressure. The traditional method requires a lot of drilling and drainage before coal mining can be carried out, which seriously restricts the green and efficient mining of coal resources. Figure 2 As shown, in order to achieve the situation of draining and reducing pressure while mining and reducing the amount of water discharged, the method for draining and reducing pressure of pressurized water of the coal mine floor proposed in this embodiment is adopted, and the specific steps are as follows:
[0082] Step 1: Obtain the mining parameters of the coal mining face. According to the borehole histogram, the conventional numerical simulation method is used to simulate the mining of the coal mining face. The mining parameters are as follows: the location of the coal mining face pressure point and the interval time of the coal mining face pressure y, y = 52 hours; the damage range of the coal mining face in the inclination direction, that is, the distance z of the mining crack extending outward along the inclination of the coal mining face, z = 8 meters; the damage depth of the coal mining face floor, that is, the vertical distance d between the coal mining face and the deepest fractured rock, d = 13 meters.
[0083] Step 2: Determine the bottom plate drainage drilling parameters according to the mining parameters. The bottom plate drainage drilling parameters include the bottom plate drainage drilling plane position, the bottom plate drainage drilling diameter point depth, the bottom plate drainage drilling end hole position, the bottom plate drainage drilling water stop casing and flower pipe position and the number of holes arranged at each pressure point. The designed bottom plate drainage drilling parameters are as follows:
[0084] Planar position of bottom plate drainage drilling holes: Take the pressure point position of the coal mining face determined in step 1 as the origin, and push it outward from the coal mining face along the inclination direction to positions ranging from 11 to 13 meters, and distribute it symmetrically along the center line of the coal mining face.
[0085] Depth of the variable diameter point of the bottom plate drainage drilling hole: The bottom plate drainage drilling hole adopts variable diameter drilling, and the drilling diameter change point is 17 meters vertically downward from the coal mining working face, that is, the depth of the variable diameter point of the bottom plate drainage drilling hole is 17 meters vertically downward from the coal mining working face. A bottom plate drainage drilling hole valve is set below the drilling diameter change point to close and open the bottom plate drainage drilling hole for water discharge.
[0086] The final position of the bottom plate water drainage drilling hole: The final position of the bottom plate water drainage drilling hole is set at a position of 20 meters from the bottom plate pressure aquifer entering the drainage.
[0087] Position of water-stopping sleeves and flower pipes in bottom plate drainage boreholes: Conventional water-stopping sleeves are designed above the borehole diameter change point of the bottom plate drainage borehole to seal and stop water. Another water-stopping sleeve is designed below the borehole diameter change point of the bottom plate drainage borehole. The water-stopping sleeve goes down to the top plate of the bottom plate pressure-bearing aquifer to be drained and seals and stops water. In the area of the bottom plate pressure-bearing aquifer to be drained, a variable flower pipe is designed. A variable flower pipe refers to a flower pipe that can freely adjust the circumferential water inlet direction, that is, a flower pipe that can arbitrarily adjust a certain azimuth section to allow water to flow or not flow in within the range of 0 to 360 degrees. The flower pipe allows the drainage water of the bottom plate pressure-bearing aquifer to enter the inside of the bottom plate drainage borehole from different directions, and then be drained to the coal mining face.
[0088] The number of holes drilled at each pressure point is obtained by numerical simulation method. The numerical simulation method includes the following steps:
[0089] (1) Establish a model based on the hydrogeological conditions and mining geological conditions of the coal mining face.
[0090] (2) Based on the coal mining face pressure point position determined in step 1, the coal mining face is divided into a plurality of coal mining blocks along the inclination direction of the coal mining face.
[0091] (3) Different numbers of bottom plate drainage holes are set on the boundary of each coal mining block. The variable flower pipe of each bottom plate drainage hole closes one-fourth of the water-passing position of the coal mining face to drain water. Finally, the stable water level in the coal mining block is below the safe mining water level. The safe mining water level is calculated based on the conventional water inrush coefficient theory.
[0092] Step 3: Drill the bottom plate drainage holes according to the design of step 2, and keep the bottom plate drainage drilling hole valve in the closed state.
[0093] Step 4: Determine the time x when the water level in the bottom plate drainage borehole reaches a stable water level. Open the bottom plate drainage borehole valve, and keep the borehole water inlet pipe in all directions (0-360° range) to allow water to enter, then record the water level of the bottom plate drainage borehole every half an hour, until the water level change is less than 0.1m or the change amplitude is less than 3% for three consecutive times, stop draining water, and close the bottom plate drainage borehole valve. The last time is recorded as the time x when the water level in the bottom plate drainage borehole reaches a stable water level. The final measured time x of the water level in the bottom plate drainage borehole reaching a stable water level is 48 hours.
[0094] Step 5: The coal mining face begins to mine coal. When mining coal in each coal mining block divided in step 2, the bottom plate drainage drilling holes within the boundary range of the coal mining block are opened to drain water, and the bottom plate drainage drilling holes are closed in the quarter of the water flow direction facing away from the coal mining face block. Since y≥x, the bottom plate drainage drilling holes outside the coal mining block are not opened. After the coal mining is pushed through the block, the bottom plate drainage drilling hole valve in the block is closed.
[0095] Step six: Complete coal mining at the coal mining face safely under drainage and pressure reduction.
[0096] By draining and reducing the pressure of coal mine floor pressurized water proposed in this embodiment, under the same conditions, the discharged water can be reduced by 25.4% and the drainage period can be reduced by 32%, thereby achieving the goal of safe, green and efficient mining.
[0097] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0098] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.
Claims
1. A method for draining and reducing the pressure of pressurized water in a coal mine floor, characterized in that: The method for draining and reducing the pressure of pressurized water in the coal mine floor comprises: Obtain mining parameters of coal mining face; Determining the bottom plate drainage drilling parameters according to the mining parameters; According to the bottom plate drainage drilling parameters, a bottom plate drainage drilling project is implemented for each coal mining section of the coal mining face; the bottom plate drainage drilling project includes drilling a number of bottom plate drainage drilling holes on the coal seam bottom plate, installing a bottom plate drainage drilling valve, and installing a bottom plate drainage drilling water stop sleeve and a flower pipe, wherein the bottom plate drainage drilling valve is used to control the open or closed state of the bottom plate drainage drilling hole, and during the implementation of the bottom plate drainage drilling project, the bottom plate drainage drilling valve is kept in a closed state; the bottom plate drainage drilling water stop sleeve and the flower pipe are used to converge the drainage water of the bottom plate pressure aquifer to the inside of the bottom plate drainage drilling hole when the bottom plate drainage drilling valve is in an open state; Based on the bottom plate drainage drilling project, drainage is performed on the bottom plate pressure aquifer in the current coal mining area, and the time when the water level in the bottom plate drainage drilling reaches a stable water level is determined; the time when the water level in the bottom plate drainage drilling reaches a stable water level refers to the time required for the drainage water of the bottom plate pressure aquifer to start flowing into the bottom plate drainage drilling after the bottom plate drainage drilling valve is opened, until the water level change of the drainage water inside the bottom plate drainage drilling is less than a threshold value within a period of time; According to the time when the water level in the bottom plate drainage borehole reaches a stable water level state, coal mining is carried out in each coal mining section of the coal mining working face.
2. The method for draining and reducing the pressure of pressurized water in a coal mine floor according to claim 1, characterized in that: Obtain the mining parameters of the coal mining face, including: According to the borehole histogram, the numerical simulation method is used to simulate the mining process of the coal mining face and obtain the mining parameters of the coal mining face.
3. The method for draining and reducing the pressure of pressurized water in a coal mine floor according to claim 1, characterized in that: The mining parameters include the location of the pressure point of the coal mining face, the interval time of the pressure on the coal mining face, the damage range in the inclination direction of the coal mining face, the damage depth of the bottom plate of the coal mining face and the location of the bottom plate pressure aquifer; among which, the damage range in the inclination direction of the coal mining face refers to the distance of the mining cracks extending outward along the inclination of the coal mining face, and the damage depth of the bottom plate of the coal mining face refers to the vertical distance between the coal mining face and the deepest fractured rock.
4. The method for draining and reducing the pressure of pressurized water in a coal mine floor according to claim 3, characterized in that: The bottom plate drainage water drilling parameters include the bottom plate drainage water drilling plane position, the bottom plate drainage water drilling diameter change point depth, the bottom plate drainage water drilling end hole position, the bottom plate drainage water drilling water stop casing and flower pipe position and the number of holes arranged at each pressure point.
5. The method for draining and reducing the pressure of pressurized water in a coal mine floor according to claim 4, characterized in that: According to the mining parameters, the bottom plate drainage drilling parameters are determined, specifically including: Determine the plane position of the bottom plate drainage drilling hole according to the pressure point position of the coal mining working face; According to the damage depth of the floor of the coal mining working face, the depth of the diameter change point of the floor drainage drilling hole is determined; Determining the final hole position of the bottom plate drainage drilling hole according to the position of the bottom plate pressure aquifer; Determine the position of the water stop sleeve and the flower pipe of the bottom plate drainage water drilling hole according to the position of the bottom plate pressure aquifer and the depth of the diameter change point of the bottom plate drainage water drilling hole; The number of drill holes arranged at each pressure point is determined according to the positions of the water-stopping casing and the flower pipe of the bottom plate drainage drilling hole and the positions of the pressure points of the coal mining working face.
6. The method for draining and reducing pressure of pressurized water in coal mine floor according to claim 1, characterized in that: Based on the floor drainage drilling project, drainage is performed on the floor pressure aquifer in the current coal mining area, and the time when the water level in the floor drainage drilling reaches a stable water level is determined, specifically including: Based on the bottom plate drainage drilling project, drainage is performed on the bottom plate pressure aquifer in the current coal mining area, and the drainage time and the water level change in the bottom plate drainage drilling hole are recorded according to a preset frequency; The time when the water level in the bottom plate drainage borehole reaches a stable water level state is determined according to the drainage time, the water level change in the bottom plate drainage borehole and the threshold.
7. The method for draining and reducing the pressure of pressurized water in a coal mine floor according to claim 6, characterized in that: The threshold is 0.
1.
8. The method for draining and reducing the pressure of pressurized water in a coal mine floor according to claim 1, characterized in that: According to the time when the water level in the bottom plate drainage borehole reaches a stable water level state, coal mining is carried out in each coal mining section of the coal mining working face, specifically including: Determine the control strategy of the bottom plate drainage water drilling hole valve according to the relationship between the time when the water level in the bottom plate drainage water drilling hole reaches a stable water level state and the interval time of the pressure coming from the coal mining working face; the bottom plate drainage water drilling hole valve control strategy refers to the strategy for controlling the opening or closing state of the bottom plate drainage water drilling hole valve corresponding to the bottom plate drainage water drilling hole during coal mining; According to the bottom plate drainage drilling valve control strategy, coal mining is carried out in each coal mining section of the coal mining working face.
9. The method for draining and reducing the pressure of pressurized water in a coal mine floor according to claim 8, characterized in that: The bottom plate drainage drilling valve control strategy includes: When the time for the water level in the bottom plate drainage borehole to reach a stable water level state is less than or equal to the pressure interval of the coal mining face, the bottom plate drainage borehole valve corresponding to the bottom plate drainage borehole outside the current coal mining section is not opened; When the time it takes for the water level in the bottom plate drainage borehole to reach a stable water level is greater than the interval time of pressure from the coal mining face, the time difference between the time it takes for the water level in the bottom plate drainage borehole to reach a stable water level and the interval time of pressure from the coal mining face is calculated, and the bottom plate drainage borehole valve corresponding to the bottom plate drainage borehole outside the current coal mining area is opened in advance at a time equal to the time difference.