A drilling method for detecting hidden structures in coal mining working faces

Abstract

The invention belongs to the technical field of coal mine geological disaster prevention and control, and relates to a drilling method for detecting hidden structures of a coal mining face; specifically, a contour map of the coal seam roof and floor of the coal mining face is first drawn; an abnormal area is drawn on the contour map; a drilling hole is designed: at the same distance, the number of drilling groups in the abnormal area is 2-3 times the number of drilling holes outside the abnormal area; the opening position, orientation, end hole position, and horizontal length of each borehole are preliminarily set; the end hole elevation is determined to be the coal seam roof and floor elevation at that location; the length and inclination parameters of the borehole are calculated; the abnormal positions of all boreholes drilled and the actual trajectory and peek of the drill track are compared and analyzed to determine the abnormal area position of the coal mining face; the invention effectively improves the drilling efficiency and saves the drilling engineering volume; different methods are adopted to perform drilling verification on the normal area and the abnormal area of ​​the working face, so as to improve the accuracy of advanced detection of hidden geological structures.

Description

Technical Field

[0001] The invention belongs to the fields of coal mine geological disaster prevention and control, coal mining technology and safety management technology, and relates to a drilling method for detecting hidden structures of a coal mining working face. Background Art

[0002] In recent years, with the continuous improvement of the comprehensive mechanization level of coal mining, the requirements for the accuracy of the identification of geological conditions in mine mining have become increasingly higher. In order to meet the needs of modern, efficient and high-yield production, accurately identifying hidden geological structures before the coal mining face has become a necessary condition for safe and efficient coal mining in coal mines. However, there are almost no systematic reports on the relatively accurate advanced geological situation forecasting technology / methods in China, and there are even fewer related application cases, especially for hidden structures such as those in coal mining faces. It is extremely urgent and necessary to accurately / precisely identify the hidden geological structures in the coal mining face and use advance detection, prediction and forecasting technology.

[0003] At present, before mining, coal mining faces need to use different methods such as geophysical exploration, drilling, and geochemical exploration to detect faults, collapse columns, old kilns, magmatic intrusions, scour zones, and other structures in the working face, accurately identify the location and scope of the structures, and create conditions for normal and safe production of the working face. A relatively complete and accurate method for advanced prediction of geological structures used in coal mines is still under exploration. At present, coal mines mainly use transient electromagnetic detection technology, slot wave seismic detection technology, tunnel radio wave perspective technology, and direct current technology to predict the geological conditions of coal mining faces. Among them, the main methods include slot wave seismic detection and tunnel radio wave perspective method, but geophysical exploration can only determine the rough position and range of faults, collapse columns, old kilns, igneous rock intrusions, scour zones and other structures existing in the coal mining face. The specific position, range, size, elements and other aspects of the structures need to be further ascertained so that safety and technical measures can be taken before mining, and reasonable avoidance or hard pushing methods can be adopted to provide reliable basic data and basis for safe production.

[0004] Therefore, current detection technologies all have the problem of low accuracy and are further affected by interference from factors such as water, construction machinery, electrical equipment, power cables and metal. At the same time, the detection results are closely related to the technical level, professional knowledge, business level and on-site experience of the analysis and processing personnel. Various detection methods have different usage conditions and applicable fields.

[0005] Therefore, in view of the shortcomings and needs of the current advance detection technology for hidden geological structures in underground coal mining faces in coal mines, it is urgent to develop an efficient, accurate, simple and systematic method for advance detection of geological structures. Summary of the invention

[0006] The present invention overcomes the shortcomings of the prior art and provides a drilling method for detecting hidden structures in a coal mining face.

[0007] In order to achieve the above object, the present invention is implemented through the following technical solutions.

[0008] A drilling method for detecting hidden structures in a coal mining face comprises the following steps:

[0009] a) Draw the contour map of the coal seam roof and floor at the coal mining face.

[0010] b) Detect the location range of the abnormal area and plot the abnormal area on the contour map.

[0011] c) Drilling design: Drilling arrangements are carried out in the abnormal area and the area outside the abnormal area: at the same distance, the number of drilling groups in the abnormal area is 2-3 times the number of drilling groups outside the abnormal area; vertically drill through holes from one side of the transport or return air chute to the relative position of the other chute, and the final holes of the drilling are drilled to the bottom plate of the coal seam, the middle of the coal seam, and the top plate of the coal seam respectively.

[0012] d) Preliminarily set the opening position, orientation, final hole position and horizontal length of each drill hole.

[0013] e) Measure the elevation of the hole at the designed hole location, predict the elevation and coal thickness of the coal seam floor at the final hole location based on the coal seam floor contour, infer the elevation of the coal seam roof, and determine the final hole elevation as the elevation of the coal seam roof and floor at that location.

[0014] f) Calculate the length and inclination parameters of the borehole based on the elevation of each borehole opening position and the elevation and horizontal length of the borehole end position.

[0015] g) After all drilling is completed, the abnormal positions of all drilling holes and the actual trajectory of the drill track and the peek are compared and analyzed to determine the location of the abnormal area of ​​the coal mining face and determine the structural elements.

[0016] Preferably, in step a, a contour map of the coal seam roof and floor of the coal mining face is drawn based on the elevations of the inlet / return air chute, the top and bottom plates of the cut eye, and the contour lines of the mining area and the mine floor revealed by the coal mining face.

[0017] Preferably, in step b, the location range of the abnormal area is detected using slot wave or pit-penetrating radio wave perspective method.

[0018] Preferably, in step c, at the same distance, the number of drilling groups in the abnormal area is twice the number of drilling holes outside the abnormal area, with 3 drilling holes in each group.

[0019] Preferably, in step d, the top and bottom plate elevations of the holes are measured at the designed drilling positions, and the opening position, orientation, final hole position, and horizontal length of each hole are preliminarily set in combination with the coal seam bottom plate contour lines.

[0020] Preferably, in step f, the length and inclination parameters of the borehole are calibrated by making a cross-sectional drawing using CAD.

[0021] After drilling is completed, the actual trajectory of the borehole is measured using a borehole trajectory meter and a peep meter, and the drilling design parameters are compared and analyzed with the actual parameters.

[0022] The beneficial effects of the present invention compared with the prior art are as follows:

[0023] The present invention focuses on detecting possible abnormal areas based on the results of geophysical exploration, and increases the density and number of detected drill holes. The contour map of the coal seam floor of the coal mining face is modified and improved according to the actual exposure of the coal seam floor in the mine, mining area, and coal mining face; the top and bottom plate elevations of the coal seam at the final hole position of the drilling are inferred based on the contour map, and then the inclination angles of each borehole are determined based on the opening elevation of the borehole and the elevation of the final hole position. Using the drawing software CAD, a coal seam profile is drawn based on the two chute and the top and bottom plates of the coal seam. According to the elevation of the borehole opening position and the elevation of the top and bottom plates of the coal seam, the drilling method is used to determine the drilling hole, and the CAD annotation function is used to calibrate the parameters of the drilling hole.

[0024] The present invention effectively improves the drilling efficiency, saves drilling time and drilling workload; adopts a systematic thinking method and comprehensively uses a variety of detection technologies for analysis and verification; grasps the main issues and key points. Different methods are adopted to drill and verify the normal and abnormal areas of the working surface, so as to improve the accuracy of advanced detection of hidden geological structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a contour map of the normal area and abnormal area detected in the embodiment.

[0026] Figure 2 for Figure 1 Cross-section of the anomalous area relative to the two sets of drill holes.

[0027] 1 is the spacing between each group of boreholes in the normal area, 2 is the spacing between each group of boreholes in the abnormal area, 3 is the predicted coal seam roof, 4 is the H7 drilling site of the 15101 return air chute, 5 is the Y7 drilling site of the 15101 transport chute; 11 is the 1# hole of the H7 drilling site; 12 is the 2# hole of the H7 drilling site; 13 is the 3# hole of the H7 drilling site; 21 is the 1# hole of the Y7 drilling site; 22 is the 2# hole of the Y7 drilling site; 23 is the 3# hole of the Y7 drilling site. DETAILED DESCRIPTION

[0028] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention is further described in detail in conjunction with the embodiments and the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. The technical solutions of the present invention are described in detail below in conjunction with the embodiments and the accompanying drawings, but the scope of protection is not limited thereto.

[0029] A drilling method for detecting hidden structures in a coal mining face comprises the following steps:

[0030] 1. After the coal mining face is circled, draw the contour map of the coal seam roof and floor of the coal mining face according to the elevation of the air inlet and return chute, the top and bottom plates of the cut-eye, and the contour lines of the mining area and the mine floor. Figure 1 The figure shows the contour map of the normal and abnormal areas detected. The channel wave or pit penetrating radio wave perspective method is used to detect the possible abnormal areas, positions and ranges of the coal mining face, and the positions and ranges of the abnormal areas are plotted on the contour map of the coal mining face.

[0031] 2. Use drilling methods to design drilling for geophysical anomaly areas. For the areas outside the anomaly area, that is, Figure 1 In the parts corresponding to A and C, one group of boreholes was constructed every 50 meters along the two drifts, with 3 boreholes in each group. Figure 1 The number 1 in the middle is the spacing between each group of boreholes in the normal area. The final holes are drilled to the coal seam, the top rock layer of the coal seam, and the bottom rock layer of the coal seam. Figure 1 In the corresponding part of B, one group of holes is constructed every 25 meters along the two drifts. Figure 1 The number 2 in the middle is the spacing of each group of boreholes in the abnormal area; vertical through-drilling is performed from one side of the transport (or return air) drift to the relative position of the other drift. Each group of 3 boreholes, the final holes are drilled to the bottom plate of the coal seam, the middle plate of the coal seam, and the top plate of the coal seam respectively.

[0032] 3. Determine the top and bottom plate elevations of the holes at the designed drilling positions, and combine the coal seam bottom plate contours to preliminarily set the drilling position, orientation, final hole position, and horizontal length of each drilling hole. 4. Determine the elevation of the drilling position at the designed drilling position, predict the coal seam bottom plate elevation and coal thickness at the final hole position based on the coal seam bottom plate contours, infer the coal seam roof elevation, and determine the final hole elevation of the three drilling holes in each group as the coal seam top and bottom plate elevation at that location. 5. Calculate the length, inclination, and other parameters of the drilling hole based on the elevation at the drilling position of each drilling hole and the elevation and horizontal length of the final hole position of the drilling hole. You can also use CAD to make a profile drawing method, and use the CAD annotation function to calibrate the length, inclination, and other parameters of the drilling hole.

[0033] 6. After all the drilling is completed, the abnormal positions of all the drillings are compared with the actual trajectory of the drilling track and the peek, and the abnormal area positions of the coal mining face are determined by analysis and the structural elements are determined.

[0034] Taking the H7 drilling site of the 15101 return air chute and the Y7 drilling site of the 15101 transport chute as examples, one group of boreholes in the H7 drilling site is drilled from the predicted coal seam roof of the 15101 return air chute to the coal seam roof in the middle, and one group of boreholes in the Y7 drilling site of the 15101 transport chute is drilled from the predicted coal seam roof of the 15101 transport chute to the coal seam roof in the middle. Figure 2 As shown,

[0035] H7 drilling site 1# hole 11: depth 90.01 meters, inclination 0°38'11";

[0036] H7 drilling site 2# hole 12: depth 90.06 meters, inclination 2°0'54";

[0037] H7 drilling site 3# hole 13: depth 90.14 meters, inclination 3°10'47';

[0038] It is predicted that the coal seam roof elevation at the final hole drilling location of H7 drilling site is 906.3; the coal seam floor elevation at the final hole drilling location of H7 drilling site is 902.3.

[0039] Y7 drilling site 1# hole 21: depth 90 meters, inclination 0°11'27";

[0040] Y7 drilling site 2# hole 22: depth 90.03 meters, inclination 1°27'50";

[0041] Y7 drilling site 3# hole 23: depth 90.1 meters, dip angle 2°44'7';

[0042] The predicted elevation of the coal seam roof at the final hole drilling location of the Y7 drilling site is 905.7; the predicted elevation of the coal seam floor at the final hole drilling location of the Y7 drilling site is 901.7.

[0043] During drilling, the operators should be experienced and familiar with the characteristics of the coal and rock layers above and below the coal seam of the mine. After drilling, the actual trajectory of the borehole is measured with a borehole tracker and a peep instrument, and the borehole design parameters are compared and analyzed with the actual parameters, and the abnormal area is located. The relevant plan and section drawings are filled in.

[0044] The above content is a further detailed description of the present invention in combination with a specific preferred embodiment. It cannot be determined that the specific embodiments of the present invention are limited to this. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the present invention, which should be regarded as belonging to the present invention and the scope of patent protection determined by the submitted claims.

Claims

1. A drilling method for detecting hidden structures in a coal mining face, characterized in that: The following steps are involved: a) Draw the contour map of the coal seam roof and floor of the coal mining face according to the elevation of the inlet / return air chute, the top and bottom plates of the cut-eye, and the contour lines of the mining area and the mine floor; b) detecting the location range of the abnormal area and plotting the abnormal area on the contour map; c) Drilling design: Drilling arrangements are made for the abnormal area and the area outside the abnormal area: at the same distance, the number of drilling groups in the abnormal area is 2-3 times the number of drilling groups outside the abnormal area; vertically drill through holes from one side of the transport or return air chute to the relative position of the other chute, and the final holes of the drilling are drilled to the bottom plate of the coal seam, the middle plate of the coal seam, and the top plate of the coal seam respectively; d) Determine the top and bottom elevations of the holes at the designed drilling locations, and preliminarily set the opening location, orientation, final hole location, and horizontal length of each hole in combination with the coal seam bottom contour lines; e) Determine the elevation of the opening at the designed drilling position, predict the elevation and thickness of the coal seam floor at the final hole position based on the coal seam floor contour, infer the elevation of the coal seam roof, and determine the final hole elevation as the elevation of the coal seam roof and floor at that location; f) According to the elevation of each drilling hole opening position and the elevation and horizontal length of the drilling hole end position, the length and inclination parameters of the drilling hole are calibrated by using the CAD profile method; g) After all drilling is completed, the abnormal positions of all drilling holes and the actual trajectory of the drill track and the peek are compared and analyzed to determine the location of the abnormal area of ​​the coal mining face and determine the structural elements.

2. A drilling method for detecting hidden structures in a coal mining face according to claim 1, characterized in that: In step b, the location range of the abnormal area is detected using slot wave or pit-penetrating radio wave perspective method.

3. A drilling method for detecting hidden structures in a coal mining face according to claim 1, characterized in that: Step c In the figure, at the same distance, the number of drilling groups in the abnormal area is twice the number of drilling groups outside the abnormal area, with 3 drilling holes in each group.

4. A drilling method for detecting hidden structures in a coal mining face according to claim 1, characterized in that: After drilling is completed, the actual trajectory of the borehole is measured using a borehole trajectory meter and a peep meter, and the drilling design parameters are compared and analyzed with the actual parameters.

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