Method for quickly determining water inrush passage of unknown area of small coal mine exploitation

Abstract

The present application relates to a method for quickly determining the water inrush channel of the Ordovician limestone in an area with unknown small coal mine mining conditions, comprising: delimiting a water inrush area in a target area on a large scale; delimiting the approximate water inrush channel range of the Ordovician limestone aquifer; determining the position of the Ordovician limestone water inrush channel; determining the development range and size of the water inrush channel; and constructing a vertical hole, followed by plugging. Advantages: avoids the disadvantages of the previous single vertical hole exploration, revealing and treating water inrush channel method, such as low probability, poor effect, long cycle; can quickly find the water inrush point, improve the speed of quick and accurate plugging of the water inrush channel, realize the quick plugging and treatment of the water inrush disaster, make the mine resume production in advance, maximize the production and economic loss caused by water disaster within the minimum damage range; can prevent the high-pressure water in the coal seam floor from continuously supplementing the upper strata vertically through the water channel, thereby reducing the mine water discharge amount, reducing the mine drainage pressure, and ensuring the safety production and economic benefits of the mine.

Description

Technical Field

[0001] This invention belongs to the field of rapid exploration and treatment technology of coal mine water inrush channels, and specifically relates to a method for rapid determination of Ordovician limestone water inrush channels in areas where the mining situation of small coal mines is unclear. Background Technology

[0002] The rapid sealing and control of water inrush at the bottom of coal seams has always been one of the major technical challenges hindering safe production in North China's coalfields. In recent years, with the depletion of shallow coal resources, coal mining has shifted to deeper levels. However, many small coal mines were previously located in the shallow areas of mines. These small mines often engaged in indiscriminate and illegal mining, exceeding the permitted seam boundaries, and were characterized by long mining histories, large areas of damage, unclear mining conditions, and insufficient data. Water inrush accidents in the goaf of these small mines occurred frequently, and locating and sealing the water outlets after an inrush was extremely difficult, posing a significant threat and challenge to mine safety. This is especially true in North China's karst-type high-water mining areas, such as some mines in the Handan-Xingtai mining area. Although all small coal mines in the shallow areas of the mining field have been closed, the extent of damage from their mining remains unclear, the mining area is large, and many water outlets still exist. Due to the complexity of hydrogeological conditions and the large number of small coal mines, many of which are mining lower coal seams, the distance between these lower coal seams and the Daqing and Ordovician aquifers is small. Sometimes, a small fault with a drop of only about 5 meters can become a channel to the underlying aquifer. Historically, there have been many water inrush accidents that have flooded the mines. Once a water inrush occurs, the amount of water entering the mine is often tens or even hundreds of times the mine's drainage capacity, causing catastrophic casualties and huge economic losses to coal mining enterprises.

[0003] Therefore, quickly locating water inrush points and accurately sealing water inrush channels is crucial. This can greatly accelerate the water inrush sealing process, achieve rapid sealing and management of water inrush disasters, and minimize the threat of water damage. It has extremely important practical guiding significance and value for the rapid resumption of mine production. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for rapidly determining the channel of Ordovician limestone inrush in areas where the mining situation of small coal mines is unknown, which effectively overcomes the defects of the prior art.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0006] A method for rapidly determining the channel of Ordovician limestone inrush in areas where the mining situation of small coal mines is unclear includes the following steps:

[0007] Step 1: Initially delineate the area of ​​potential water inrush within the target region;

[0008] Step 2: Based on the principle that a drop funnel will form centered on the drop point after the water inrush in the Ordovician limestone aquifer, and that the central area of ​​the drop funnel is the largest possible area for the water inrush channel, multiple Ordovician limestone aquifer hydrological boreholes and microseismic monitoring boreholes will be constructed in a large-scale network within the water inrush area delineated in Step 1. The water level of the Ordovician limestone aquifer will be observed using the hydrological boreholes, and the Ordovician limestone iso-level map will be analyzed and drawn in real time. Microseismic monitoring information will be collected using the microseismic monitoring boreholes as a basis for guiding the next step of borehole layout, and finally the approximate range of the water inrush channel of the Ordovician limestone aquifer will be delineated.

[0009] Step 3: Based on the contour map of the Ordovician limestone aquifer, in the central section of the drop cone, further arrange and construct hydrological boreholes for the Ordovician limestone aquifer on the side with the smaller hydraulic gradient. Observe the water level, draw and analyze the contour map of the Ordovician limestone aquifer, find the section with the lower Ordovician limestone water level, and add microseismic monitoring boreholes as needed. Continue this process in a cyclical manner to gradually narrow down the range of the water inrush channel, thereby determining the approximate location of the Ordovician limestone water inrush channel.

[0010] Step 4: In the area with the highest probability of water inrush, take advantage of the fast construction speed and accurate positioning of the branch holes and the fact that the water inrush channel must pass through the top impermeable layer of the Ordovician limestone. Arrange horizontal branch holes to quickly and accurately locate the water inrush channel. Place the horizontal branch holes in the stable and high-strength impermeable rock layer at the top of the Ordovician limestone. Construct the horizontal branch holes in sequence and gradually reduce the spacing of the horizontal branch holes in sequence until the location of the Ordovician limestone water inrush point is accurately determined. Then, construct secondary branch holes on both sides of the determined Ordovician limestone water inrush point location to determine the development range and size of the water inrush channel.

[0011] Step 5: Based on the development range and size of the water inrush channel determined in Step 4, construct a vertical hole directly above it, and then seal it.

[0012] Based on the above technical solution, the present invention can be further improved as follows.

[0013] Furthermore, in step two above, the borehole spacing of the Ordovician limestone aquifer hydrological boreholes is 500-600m, and the spacing between the hydrological observation boreholes and the microseismic monitoring boreholes is 5m.

[0014] Furthermore, in step four above, the horizontal branch holes are constructed in a three-level sequence, with the spacing between the first-order horizontal holes being 20m, the spacing between the second-order horizontal holes being 10m, and the spacing between the third-order horizontal holes being 5m.

[0015] Furthermore, in step five above, grouting is used for sealing.

[0016] Furthermore, an automatic water level monitoring system was deployed in the hydrological wells of the aforementioned Ordovician limestone aquifer, and microseismic detectors were installed in the microseismic monitoring wells at locations corresponding to the Ordovician limestone and bedrock layers.

[0017] Furthermore, the hydrological boreholes of the aforementioned Ordovician limestone aquifer were constructed using truck-mounted drills, the vertical boreholes of the aforementioned horizontal branch boreholes were constructed using truck-mounted drills, and the directional horizontal boreholes of the aforementioned horizontal branch boreholes were constructed using tower drilling rigs.

[0018] The beneficial effects of this invention are: it avoids the drawbacks of previous methods of using single vertical boreholes to explore, expose, and manage water inrush channels, which have low probability, poor effect, and long cycle; it can quickly locate water inrush points, improve the speed of rapid and accurate sealing of water inrush channels, achieve rapid sealing and management of water inrush disasters, enable mines to resume production in advance, and minimize the production and economic losses caused by water hazards; it can prevent high-pressure water from the coal seam floor from continuously replenishing the upper strata vertically through the water guide channel, thereby reducing the mine's drainage volume, alleviating the mine's drainage pressure, and ensuring the mine's safe production and economic benefits. Attached Figure Description

[0019] Figure 1 This is a schematic diagram illustrating the delineation of the water inrush area in the method for rapidly determining the water inrush channel in Ordovician limestone in areas where the mining situation of small coal mines is unclear, as described in this invention.

[0020] Figure 2 This is a diagram showing the distribution of hydrological boreholes and microseismic monitoring boreholes in the Ordovician limestone aquifer, as well as the distribution of horizontal branch boreholes constructed in sequence, in the method for rapid determination of water inrush channels in Ordovician limestone aquifers in areas where the mining situation of small coal mines is unknown, according to the present invention.

[0021] Figure 3 This is a schematic diagram illustrating the method for rapidly determining the Ordovician limestone inrush channel in areas where the mining situation of small coal mines is unclear, involving the construction of vertical holes above the inrush channel for sealing. Detailed Implementation

[0022] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0023] Example: The method for rapidly determining the Ordovician limestone inrush water channel in areas where the mining situation of small coal mines is unknown includes the following steps:

[0024] Step 1: First, based on existing data on small coal mines and exploration methods such as on-site reconnaissance, surveys, and transient electromagnetic exploration, determine the location, number, distribution, and mining conditions of the small coal mines (mined coal seams, mining elevations, etc.). Then, combine this with preliminary hydrogeological information from investigations of mine water inrush areas and water inrush volumes, as well as hydrogeological information from observations of the Ordovician limestone aquifer water level in the mine water inrush area, to preliminarily delineate the water inrush area over a large area within the target region. Figure 1 (M in the middle refers to the area where the water inrush occurred);

[0025] Step Two: Based on the premise that a drop funnel will form centered on the point of water inrush after the Ordovician limestone aquifer, and that the central area of ​​the drop funnel is the most likely area of ​​the Ordovician limestone aquifer water inrush channel, multiple Ordovician limestone aquifer hydrological boreholes (represented by S in the diagram) and microseismic monitoring boreholes (such as...) are constructed in a network pattern within the delineated water inrush area in Step One. Figure 2 As shown in the figure (W represents), the borehole spacing of the Ordovician limestone aquifer hydrological boreholes is 500-600m, and the spacing between the hydrological observation boreholes and the microseismic monitoring boreholes is 2-5m. An automatic water level observation system is installed in the above-mentioned Ordovician limestone aquifer hydrological boreholes, and microseismic geophones are installed in the above-mentioned microseismic monitoring boreholes at the locations corresponding to the Ordovician limestone and bedrock layers. The water level in the Ordovician limestone aquifer is observed using the automatic water level observation system in the Ordovician limestone aquifer hydrological boreholes, and the Ordovician limestone iso-water level map is analyzed and drawn in real time. The microseismic monitoring information is collected using the microseismic geophones in the microseismic monitoring boreholes as a basis for guiding the next borehole layout, and finally the approximate water inrush channel range of the Ordovician limestone aquifer is delineated.

[0026] Step 3: Based on the Ordovician limestone aquifer contour map, in the central section of the drop cone, further arrange and construct Ordovician limestone aquifer hydrological boreholes on the side with the smaller hydraulic gradient. Observe the water level, draw and analyze the Ordovician limestone contour map, find areas with lower Ordovician limestone water levels, and appropriately increase the number of microseismic monitoring boreholes as needed. Continue this process in a cyclical manner to gradually narrow down the range of the water inrush channel, thereby determining the approximate location of the Ordovician limestone water inrush channel.

[0027] Step 4: In the area with the highest probability of water inrush (T in the diagram), horizontal branch boreholes are arranged to accurately locate the water inrush channel. Taking advantage of the characteristic that the water inrush channel always passes through the top impermeable layer of the Ordovician limestone, the horizontal branch boreholes are placed within the stable and high-strength impermeable rock layer at the top of the Ordovician limestone. (This arrangement of strata allows for rapid construction, and if leakage occurs, it is highly likely to be the location of the highest probability water inrush channel, thus quickly identifying the channel.) Therefore, on the one hand, it avoids the impact of extensive grouting in the Ordovician limestone strata (non-water inrush location) by drilling (hydrological boreholes), which would affect the construction speed, and on the other hand, it can quickly and accurately determine the location of the Ordovician limestone inrush point. The location of the water inrush point is determined by constructing horizontal branch holes in sequence. The spacing between the first-sequence horizontal holes is 20m (in the diagram, probes 1-5 represent the first-sequence horizontal branch holes), the spacing between the second-sequence horizontal holes is 10m (in the diagram, probes 6 and 7 represent the second-sequence horizontal branch holes), and the spacing between the third-sequence horizontal holes is 5m (in the diagram, probes 8 and 9 represent the third-sequence horizontal branch holes). The spacing between the horizontal branch holes is gradually reduced until the location of the water inrush point in the Ordovician limestone is accurately determined. Then, secondary branch holes are constructed on both sides of the determined location of the water inrush point to determine the development range and size of the water inrush channel.

[0028] Step 5: Based on the development range and size of the water inrush channel determined in Step 4, construct a vertical hole (represented by Z in the diagram) or a horizontal branch hole directly above it, followed by sealing. To quickly address the water inrush channel, multiple drilling rigs can be used in parallel operations (e.g., Figure 3 As shown, the hydrological boreholes of the Ordovician limestone aquifer were drilled using a truck-mounted drill, the vertical boreholes of the horizontal branch boreholes were drilled using a truck-mounted drill, and the directional horizontal boreholes of the horizontal branch boreholes were drilled using a tower drill, which can further improve construction efficiency.

[0029] It should be further explained that: the particle size and amount of aggregate to be added are determined according to the condition of the vertical holes of the perforation, and the grouting is carried out in combination with the changes in the water volume in the well and the condition of the surrounding Ordovician limestone observation holes. During the sealing process, a dedicated person is arranged to monitor the changes in water volume and quality at the water inrush point in the well 24 hours a day, and a video monitoring system is installed to monitor the real-time situation of water blocking and water control work in the well and above and below. The obtained data is used to further optimize and improve the grouting and water control plan, and finally completely seal the water inrush point.

[0030] The method described in this embodiment is suitable for the rapid and accurate identification and control of water inrush channels in Ordovician limestone mines in areas with unclear mining conditions. This method avoids the drawbacks of previous methods involving vertical borehole exploration, exposure, and control of water inrush channels, which suffer from low probability, poor effectiveness, and long cycles. Using this rapid and accurate water-blocking technology for Ordovician limestone water inrush channels, the inrush point can be quickly located, improving the speed of rapid and accurate blocking of the water inrush channel, achieving rapid blocking and control of water inrush disasters, enabling the mine to resume production ahead of schedule, and minimizing the production and economic losses caused by water hazards. Simultaneously, it prevents high-pressure water from the coal seam floor from continuously replenishing the upper strata vertically through the water guide channel, thereby reducing the mine's drainage volume, alleviating drainage pressure, ensuring safe production and economic benefits, and having significant social and ecological benefits for the preservation and continuous improvement of local water resources and the ecological environment.

[0031] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for rapidly determining the channel of water inrush from Ordovician limestone in areas where the mining situation of small coal mines is unclear, characterized in that, Includes the following steps: Step 1: Based on the location data of small coal mines and the investigation of water outflow areas, preliminarily delineate the water inrush area over a large area in the target region; Step 2: Based on the principle that a drop funnel will form centered on the drop point after the water inrush in the Ordovician limestone aquifer, and that the central area of ​​the drop funnel is the largest possible area for the water inrush channel, multiple Ordovician limestone aquifer hydrological boreholes and microseismic monitoring boreholes will be constructed in a large-scale network within the water inrush area delineated in Step 1. The water level of the Ordovician limestone aquifer will be observed using the hydrological boreholes, and the Ordovician limestone iso-level map will be analyzed and drawn in real time. Microseismic monitoring information will be collected using the microseismic monitoring boreholes as a basis for guiding the next step of borehole layout, and finally the approximate range of the water inrush channel of the Ordovician limestone aquifer will be delineated. Step 3: Based on the Ordovician limestone aquifer contour map, in the central section of the drop cone, further arrange and construct Ordovician limestone aquifer hydrological boreholes on the side with the smaller hydraulic gradient. Observe the water level, draw and analyze the Ordovician limestone contour map, find areas with lower Ordovician limestone water levels, and appropriately increase the number of microseismic monitoring boreholes as needed. Continue this process in a cyclical manner to gradually narrow down the range of the water inrush channel, thereby determining the approximate location of the Ordovician limestone water inrush channel. Step 4: In the area with the highest probability of water inrush, take advantage of the fast construction speed and accurate positioning of the branch holes and the fact that the water inrush channel must pass through the top impermeable layer of the Ordovician limestone. Arrange horizontal branch holes to quickly and accurately locate the water inrush channel. Place the horizontal branch holes in the stable and high-strength impermeable rock layer at the top of the Ordovician limestone. Construct the horizontal branch holes in sequence and gradually reduce the spacing of the horizontal branch holes in sequence until the location of the Ordovician limestone water inrush point is accurately determined. Then, construct secondary branch holes on both sides of the determined Ordovician limestone water inrush point location to determine the development range and size of the water inrush channel. Step 5: Based on the development range and size of the water inrush channel determined in Step 4, construct a vertical hole directly above it, and then seal it. In step two, the borehole spacing for the Ordovician limestone aquifer hydrological wells is 500-600m, and the spacing between the hydrological observation wells and the microseismic monitoring wells is 2-5m; In step four, the horizontal branch holes are constructed in a three-level sequence, with the first sequence of horizontal holes having a spacing of 20 m, the second sequence having a spacing of 10 m, and the third sequence having a spacing of 5 m.

2. The method for rapidly determining the channel of Ordovician limestone inrush in areas with unclear mining conditions in small coal mines, as described in claim 1, is characterized in that: In step five, grouting is used for sealing.

3. The method for rapidly determining the channel of Ordovician limestone inrush in areas with unclear mining conditions in small coal mines, as described in claim 1, is characterized in that: An automatic water level monitoring system is installed in the hydrological boreholes of the Ordovician limestone aquifer, and microseismic detectors are installed in the microseismic monitoring boreholes at positions corresponding to the Ordovician limestone and bedrock layers.

4. The method for rapidly determining the channel of Ordovician limestone inrush in areas with unclear mining conditions in small coal mines, as described in claim 1, is characterized in that: The hydrological boreholes of the Ordovician limestone aquifer were constructed using truck-mounted drills, the vertical boreholes of the horizontal branch boreholes were constructed using truck-mounted drills, and the directional horizontal boreholes of the horizontal branch boreholes were constructed using tower drill rigs.

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