Method for long-distance exploration and drainage of accumulated water in goaf

Abstract

The invention discloses a method for remotely exploring and draining accumulated water in a goaf, which relates to the field of underground coal mine drilling and comprises the following steps of: constructing a directional exploring and draining drill hole from a working face to the goaf in a forward crossing manner by using a directional drilling machine; the directional water exploration and drainage drill hole firstly penetrates downwards to a stable sandstone layer, then extends along the stable sandstone layer along the bedding layer, and finally extends to a goaf at an elevation angle; after construction is completed, accumulated water in the goaf is drained through potential energy difference. The method has the advantages that the accuracy and safety of water exploration and drainage in the goaf are improved, and the overall production efficiency of a coal mine is improved.

Description

Technical Field

[0001] The invention relates to the field of underground drilling in coal mines, and in particular to a method for long-distance detection and discharge of water accumulation in goaf areas. Background Art

[0002] Water accumulation in the goaf of a mine has always been one of the major hidden dangers to coal mine safety production. In the past, most of the exploration and release methods along the goaf were adopted to explore the water accumulation in the goaf, which not only seriously restricted the efficiency of tunnel excavation, but also posed a great threat to safety. In recent years, the scope of coal mine development, mining depth and intensity have been continuously expanded, and the hydrogeological conditions of coal mines have become increasingly complex. At the same time, underground directional drilling rigs have become increasingly mature in equipment and technology, providing support for long-distance and precise exploration and release of water accumulation in goafs.

[0003] The patent document with the publication number CN118030182A discloses a method for draining water from coal mine goafs, in which multiple boreholes are drilled on the wall of the drainage tunnel, and the boreholes are used to drain the goafs. The existing method for draining water from goafs similar to the above method is a close-range exploration and release mode, that is, cyclic pressure-limited exploration and release is performed using the adjacent bottom tunnel of the goaf or the tunnel along the goaf. The exploration and drainage equipment is mainly an ordinary drilling rig. This mode mainly has the following problems: First, non-directional drilling, poor drilling accuracy, difficult to control the drilling trajectory, unable to achieve precise drainage at a fixed point, a large number of boreholes required, and low work efficiency; second, the exploration distance is small, and close-range operation is required. Once water inrush occurs, it poses a huge threat to the personal safety of construction personnel in the operation area; third, cyclic pressure-limited exploration and drainage affects tunnel excavation, thereby affecting the overall production efficiency of the coal mine. Summary of the invention

[0004] The technical problem to be solved by the present invention is how to improve the accuracy and safety of water detection and drainage in goaf areas and improve the overall production efficiency of coal mines.

[0005] The present invention solves the above technical problems through the following technical means: a method for long-distance exploration and release of water in goaf, comprising the following steps: using a directional drilling rig to construct a directional exploration and release water borehole from the working face across the entire working face to the goaf; the directional exploration and release water borehole first penetrates down to the stable sandstone layer, then extends along the stable sandstone layer, and finally extends to the goaf at an elevation; after the construction is completed, the water in the goaf is released by utilizing the potential energy difference.

[0006] As an optimized technical solution, the inclination angle of the directional water exploration and drainage borehole passing through the stable sandstone layer is -8° to -10°.

[0007] As an optimized technical solution, the method for constructing a directional water exploration and drainage drilling hole includes the following steps:

[0008] Step 1: Drilling holes;

[0009] Step 2, expanding the hole;

[0010] Step 3: Install casing and fix the pipe;

[0011] Step 4: Conduct a withstand voltage test;

[0012] Step 5: Install gate valve and orifice blowout prevention device;

[0013] Step 6: insert the directional drilling tool into the hole, and construct the directional exploration and drainage drilling hole according to the designed trajectory until the goaf is penetrated;

[0014] Step seven, withdraw the drill rod and complete the directional water exploration and drainage drilling construction.

[0015] As an optimized technical solution, in step one, the hole-opening method is to use a composite drill bit and a stabilizer to drill at least 25m.

[0016] As an optimized technical solution, in step two, the hole enlarging method is to use a drill bit with a gradually increasing diameter to enlarge the hole in multiple stages to the opening depth.

[0017] As an optimized technical solution, in step three, the casing is lowered to the stable sandstone layer.

[0018] As an optimized technical solution, in step three, the casing adopts a core tube, and the outer end of the outermost casing is provided with a flange, and the length of each casing is greater than or equal to 20m.

[0019] As an optimized technical solution, in step three, use 32.5 cement to fix the pipe, and the cement grouting pressure is greater than or equal to 4MPa.

[0020] As an optimized technical solution, in step four, the method for conducting a pressure test is: after the solidified pipe has solidified for more than 48 hours, a composite drill bit is used to sweep the hole and drill to a position at least 1m beyond the bottom of the casing, and then a grouting pump is used to inject clean water to make the pressure reach 1.4-1.6MPa. After the pressure stabilizes for more than 40 minutes, if the orifice casing is not loose, and there is no water leakage or seepage at the orifice and its surroundings, the pressure test is qualified.

[0021] As an optimized technical solution, in step six, during the directional water exploration and drainage drilling construction process, the slag removal is carried out by combining the slag removal in sequence and the slag removal in shifts.

[0022] The advantages of the present invention are:

[0023] 1. Directional drilling using a directional drilling rig can accurately control the trajectory of directional water exploration and drainage drilling holes. The directional water exploration and drainage drilling hole landing point error is small, and precise drainage at a fixed point is achieved. The number of holes required is small, and the work efficiency is high.

[0024] 2. The water exploration and release site is located in the smooth operation of the working face, far away from the goaf, thus ensuring the personal safety of construction workers in the working area.

[0025] 3. During the directional water exploration and drainage drilling process, the forward excavation does not need to be stopped and can be carried out continuously, which improves the overall production efficiency of the coal mine.

[0026] 4. The design adopts a U-shaped drilling solution. Most of the directional exploration and water-draining drilling holes are located in stable sandstone layers, which effectively solves the problem of directional exploration and water-draining drilling holes being prone to cross-holes when exploring and draining water from the working face across the working face.

[0027] 5. Use U-shaped channels to drain water to avoid the outflow of toxic and harmful gases from the goaf. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic cross-sectional view of a directional water exploration and release drilling hole according to an embodiment of the present invention.

[0029] Figure 2 It is a longitudinal cross-sectional schematic diagram of a directional water exploration and release drilling hole according to an embodiment of the present invention.

[0030] Figure 3 It is a curve diagram showing the change of water discharge volume over time in a directional water exploration and discharge drilling hole according to an embodiment of the present invention.

[0031] Figure 4 It is a bar graph showing the cumulative total water release volume of directional exploration and water release drilling holes changing over time according to an embodiment of the present invention. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] The embodiment of the present invention discloses a method for remotely detecting and releasing water in a goaf area, comprising the following steps:

[0034] like Figure 1 , Figure 2As shown, a directional drilling rig is used to construct a directional water exploration and drainage borehole 3 from the working face 1 across the entire working face 4 to the goaf 2; the directional water exploration and drainage borehole 3 first penetrates down to the stable sandstone layer 5 at an inclination angle of -8° to -10°, then extends along the stable sandstone layer 5, and finally extends to the goaf 2 at an elevation angle; after the construction is completed, the accumulated water in the goaf 2 is released by using the potential energy difference; the directional drilling rig can accurately control the trajectory of the directional water exploration and drainage borehole 3, ensuring that the landing point error of the directional water exploration and drainage borehole 3 is within 1m, realizing fixed-point precise drainage, requiring a small number of boreholes, and high work efficiency; The water discharge location is set at the working face Yunshun 1, which is more than 350m away from the goaf 2, which is 10 times the safe exploration and discharge distance, ensuring the personal safety of construction personnel in the working area; during the construction of the directional exploration and discharge drilling hole 3, the head-on excavation does not need to be stopped and continuous operation can be carried out, which improves the overall production efficiency of the coal mine; the design adopts a U-shaped drilling scheme, and most of the directional exploration and discharge drilling holes 3 are located in the stable sandstone layer 5, which effectively solves the problem that the directional exploration and discharge drilling holes 3 are easy to cross the hole when the working face Yunshun 1 crosses the working face 4 for exploration and discharge; a U-shaped channel is used for water discharge to avoid the outflow of toxic and harmful gases in the goaf 2.

[0035] The construction method of the directional water exploration and drainage drilling hole 3 comprises the following steps:

[0036] Step 1: Drilling: Use a 120mm composite drill bit and a stabilizer to drill at least 25m.

[0037] Step 2, hole enlargement: use drill bits with gradually increasing diameters to enlarge the hole in multiple stages to the opening depth. This embodiment uses two-stage drill bits of Ф153mm and Ф196mm.

[0038] Step three, lowering casing and fixing pipes: The lithology of the directional exploration and drainage borehole 3 is broken in the mudstone section, so the casing is lowered to the stable sandstone layer 5, and the quality control during the lowering of casing and grouting is strengthened to ensure the success of the subsequent pressure test; the casing adopts a Φ146mm core tube, and the outermost casing is provided with a flange at the outer end, and the length of each casing is greater than or equal to 20m; 32.5 cement is used to fix the pipe, and the cement grouting pressure is greater than or equal to 4MPa.

[0039] Step 4: Conduct a pressure test: After the solidified pipe has solidified for more than 48 hours, use a Φ120mm composite drill bit to drill to a position at least 1m beyond the bottom of the casing, and then use a grouting pump to inject clean water to make the pressure reach 1.4-1.6MPa. After the pressure stabilizes for more than 40 minutes, if the orifice casing is not loose, and there is no water leakage or seepage at the orifice and its surroundings, the pressure test is qualified.

[0040] Step five: Install the gate valve and orifice blowout preventer.

[0041] Step six, lower the directional drilling tool into the hole, and construct the directional exploration and drainage drilling hole 3 according to the designed trajectory until the goaf 2 is penetrated; during the construction of the directional exploration and drainage drilling hole 3, the construction trajectory is strictly controlled, and the slag is removed by combining the slag removal in sequence and the slag removal in shifts to ensure the quality of the hole.

[0042] Step seven, withdraw the drill rod, and the construction of directional water exploration and drainage drilling hole 3 is completed.

[0043] like Figure 3 , Figure 4 As shown in the figure, after the test, after the construction of directional exploration and drainage drilling hole 3, the initial water inflow was 29.6m 3 / h, to the maximum water inflow of 123m 3 / h, and finally stabilized at 45m 3 / h, cumulatively releasing 30,000 m3 of accumulated water 3 , average water flow 45m 3 / h, within 15 days, the water accumulation height in goaf 2 dropped from 54.1m to 17.6m. The water release effect was good and the results were remarkable.

[0044] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for remotely detecting and releasing water from a goaf, characterized in that: The following steps are involved: A directional drilling rig is used to construct a directional water exploration and drainage borehole from the working face across the entire working face to the goaf; the directional water exploration and drainage borehole first penetrates down to the stable sandstone layer, then extends along the stable sandstone layer, and finally extends to the goaf at an elevation; after the construction is completed, the water accumulated in the goaf is released by utilizing the potential energy difference.

2. The method for remotely detecting and releasing water from a goaf as claimed in claim 1, characterized in that: The inclination angle of the directional water exploration and drainage borehole passing down to the stable sandstone layer is -8° to -10°.

3. The method for remotely detecting and releasing water from a goaf as claimed in claim 1, characterized in that: The method for constructing a directional water exploration and drainage borehole comprises the following steps: Step 1: Drilling holes; Step 2, expanding the hole; Step 3: Install casing and fix the pipe; Step 4: Conduct a withstand voltage test; Step 5: Install gate valve and orifice blowout prevention device; Step 6: insert the directional drilling tool into the hole, and construct the directional exploration and drainage drilling hole according to the designed trajectory until the goaf is penetrated; Step seven, withdraw the drill rod and complete the directional water exploration and drainage drilling construction.

4. The method for remotely detecting and releasing water from a goaf as claimed in claim 3, characterized in that: In step 1, the drilling method is: use a composite drill bit and a stabilizer to drill at least 25m.

5. The method for remotely detecting and releasing water from goaf areas as claimed in claim 3, characterized in that: In step 2, the hole enlarging method is: using a drill bit with a gradually increasing diameter to enlarge the hole in multiple stages to the opening depth.

6. The method for remotely detecting and releasing water from a goaf as claimed in claim 3, characterized in that: In step three, the casing is lowered into the stable sandstone layer.

7. The method for remotely detecting and releasing water from a goaf as claimed in claim 3, characterized in that: In step three, the casing adopts a core tube, and the outer end of the outermost casing is provided with a flange, and the length of each casing is greater than or equal to 20m.

8. The method for remotely detecting and releasing water from a goaf as claimed in claim 3, characterized in that: In step three, 32.5 cement is used to fix the pipe, and the cement grouting pressure is greater than or equal to 4MPa.

9. The method for remotely detecting and releasing water from a goaf as claimed in claim 3, characterized in that: In step 4, the method for conducting the pressure test is: after the solidified pipe has solidified for more than 48 hours, a composite drill bit is used to sweep the hole and drill to a position at least 1m beyond the bottom of the casing, and then a grouting pump is used to inject clean water to make the pressure reach 1.4-1.6MPa. After the pressure stabilizes for more than 40 minutes, if the orifice casing is not loose, and there is no water leakage or seepage at the orifice and its surroundings, the pressure test is qualified.

10. The method for remotely detecting and releasing water from a goaf as claimed in claim 3, characterized in that: In step six, during the directional water exploration and drainage drilling construction process, the slag is discharged by combining the slag discharge in sequence and the slag discharge in shifts.

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