A construction method suitable for comprehensive prevention and control of coal rock dynamic disaster

Abstract

The application discloses a method suitable for comprehensive prevention and control of coal rock dynamic disaster, and relates to the technical field of coal mining. The method suitable for comprehensive prevention and control of coal rock dynamic disaster comprises the following steps: S1, determining the position of a coal rock layer to be pre-split; S2, determining the position of a drilling site; S3, determining the position of a borehole and a plurality of pre-split paths corresponding to the borehole in the coal rock layer to be pre-split; S4, performing a directional long borehole construction process, and drilling a horizontal long borehole in the coal rock layer to be pre-split; S5, performing directional cutting operation of the horizontal long borehole; S6, performing backward segmented pre-splitting; and S7, repeating steps S4 to S6, and completing pre-splitting operation of the plurality of pre-split paths in the coal rock layer to be pre-split. The method suitable for comprehensive prevention and control of coal rock dynamic disaster can realize comprehensive treatment of the coal rock layer in all directions, carry out large-scale pre-splitting operation, ensure pressure relief and permeability improvement effects of pre-splitting fissures, and ensure safe production of coal mining operation.

Description

Technical Field

[0001] The present invention relates to the technical field of coal mining, and in particular to a method suitable for comprehensive prevention and control of coal and rock dynamic disasters. Background Art

[0002] Before mining, the coal and rock masses underground are in a relatively balanced original rock stress state. With the mining of the coal seam, the initial balanced state of the original rock stress is broken, resulting in local stress concentration. Under the superimposed influence of dynamic load disturbance stress, the coal and rock masses that exceed the limit suddenly break on a large scale, which means there is a risk of inducing dynamic disaster accidents. With the continuous increase in coal mining depth and the continuous increase in mining intensity, coal and rock dynamic disasters become more and more obvious, and coal and rock dynamic disaster accidents continue to occur.

[0003] Relevant technologies often adopt a multi-technique coordination approach, such as deep hole blasting technology, hydraulic fracturing technology, roof cutting and pressure relief technology in roof treatment; large diameter drilling and pressure relief technology, coal seam jet cutting technology, coal body blasting technology and other technologies in coal seam treatment; bottom coal drilling and pressure relief technology, bottom breaking blasting technology, bottom plate cutting technology and other technologies in floor treatment.

[0004] However, the following problems exist during the construction process: the treatment scope is small. Affected by the applicability of the technology and process equipment, the vertical depth of the roof corresponding to the roof of the roof treatment technology generally does not exceed 30 to 50 meters, the vertical depth of the floor corresponding to the floor treatment technology generally does not exceed 30 meters, and the horizontal extension of the coal seam treatment technology generally does not exceed 150 meters; the treatment effect is single, and only targeted treatment is carried out on the local roof, coal seam or floor. The effect on local emergency relief is more obvious, but the effect on large-scale stress regulation and structural optimization is weak; the treatment timing is limited, generally as the working face is mined beyond the front working face by about 300 meters, or after 30 to 50 meters of excavation, it is often affected by cross-operation; the construction efficiency is low. In order to achieve better treatment effects, a single-section multi-technology fan-shaped operation layout is often adopted, which has high labor intensity and low engineering efficiency, and there are also high safety hazards during the construction process. Summary of the Invention

[0005] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0006] To this end, an embodiment of the present invention proposes a "11N" method suitable for the comprehensive prevention and control of coal and rock dynamic disasters. The "11N" method suitable for the comprehensive prevention and control of coal and rock dynamic disasters can achieve all-round comprehensive management of high-level thick hard rock layers, medium-level thick hard rock layers, low-level thick hard rock layers, deep mining area surrounding rocks and hard coal seams, hard bottom plates, etc. overlying coal seams, carry out large-scale pre-cracking operations, ensure the pressure relief and permeability enhancement effects of pre-cracking fissures, realize safe mining of coal seams at the source, avoid the occurrence of dynamic disasters such as rock burst, coal and gas outbursts, and ensure safe production of coal mine operations.

[0007] The "11N" method for comprehensive prevention and control of coal and rock dynamic disasters according to an embodiment of the present invention includes the following steps:

[0008] S1: Determine the location of the coal stratum to be pre-splitting;

[0009] S2: Determine the drilling site location;

[0010] S3: placing a high-pressure pump group, determining the drilling position and multiple pre-splitting paths corresponding to the drilling holes in the coal rock layer to be pre-splitting;

[0011] S4: Construction is carried out by using a directional long drilling process, in which a horizontal long borehole is drilled along the pre-splitting path in the coal stratum to be pre-splitting;

[0012] S5: performing directional cutting operations on the horizontal long borehole in the location of the coal and rock layer to be pre-splitting, and forming multiple cutting points in the horizontal long borehole;

[0013] S6: After the horizontal long borehole is drilled, the pre-splitting is performed in a backward segmented pre-splitting manner, and the pre-splitting segment is aligned with the cutting point. After the entire pre-splitting of the horizontal long borehole is completed, the drill is withdrawn;

[0014] S7: Repeat steps S4 to S6 to complete the pre-splitting operation of multiple pre-splitting paths in the coal rock layer to be pre-splitting.

[0015] The "11N" method suitable for comprehensive prevention and control of coal and rock dynamic disasters in the embodiment of the present invention can achieve all-round comprehensive management of high-level thick hard rock layers, medium-level thick hard rock layers, low-level thick hard rock layers, deep mining area surrounding rocks and hard coal seams, hard bottom plates, etc. overlying coal seams, carry out large-scale pre-cracking operations, ensure the pressure relief and permeability enhancement effects of pre-cracking fissures, realize safe mining of coal seams at the source, avoid the occurrence of dynamic disasters such as rock burst, coal and gas outbursts, and ensure safe production of coal mine operations.

[0016] In some embodiments, in step S2, the drilling site is set to one of the following locations: a horizontal tunnel, a mining area tunnel, a mining face tunnel, an excavation face tunnel, a special measures tunnel, a special chamber, or an area corresponding to the ground.

[0017] In some embodiments, a drilling site is set up on the ground, and pre-splitting operations are performed on at least one coal rock layer to be pre-splitting through a single borehole, and horizontal long boreholes are drilled and pre-splitting along multiple pre-splitting paths in the single coal rock layer to be pre-splitting.

[0018] In some embodiments, the drilling site is set up in a horizontal main tunnel. In step S4, multiple mining areas are pre-cracked by drilling, and the drilling is carried out in an inclined upward direction to the coal rock layer to be pre-cracked. When the working face is perpendicular to the horizontal main tunnel for mining operations, a directional long drill hole is constructed in the corresponding pre-cracked rock layer along the extension direction of the working face. When the working face is parallel to the horizontal main tunnel for mining operations, the long drill hole simultaneously passes through the rock layers corresponding to the cutting eyes, square areas, stop mining lines, and abnormal structural areas of multiple working faces.

[0019] In some embodiments, the drilling site is set up in the main tunnel of the mining area. In step S4, multiple mining areas are pre-cracked by drilling, and the drilling is carried out in an inclined upward direction to the coal rock layer to be pre-cracked. In the rock layer corresponding to the mining area, a directional long drill hole is constructed along the extension direction of the working face.

[0020] In some embodiments, the drilling site is set in the tunnel of the excavation working face or the tunnel of the mining working face. In step S4, multiple working faces are pre-cracked by drilling, and drilling is carried out in an inclined upward direction to the coal rock layer to be pre-cracked. Corresponding to the adjacent working face, directional long drill holes are arranged in the coal rock layer to be pre-cracked in a direction perpendicular to the extension direction of the working face or in a direction parallel to the extension direction of the working face.

[0021] In some embodiments, the drilling site is set up in a dedicated measure tunnel. In step S4, multiple working faces are pre-cracked by drilling, and the coal rock layer to be pre-cracked is drilled in an inclined upward direction. Corresponding to the adjacent working face, a directional long drill hole is constructed along the extension direction of the working face.

[0022] In some embodiments, the drilling site is set up in a chamber. In step S4, with the chamber as the center, the coal and rock layers to be pre-cracked corresponding to the working face cut, the two leading drifts, and the stop-mining line within a radius of 100 to 1500 m are pre-cracked.

[0023] In some embodiments, when arranging drilling holes, a judgment is made on the pre-cracked coal and rock formations. If pre-cracked and permeability-enhancing operations and directional cutting operations are performed in the coal seams, for coal seams with a Pugh strength coefficient f value of 1.6 or above, directional long boreholes can be directly constructed in the coal seams, and directional cutting and high-pressure pre-cracked operations can be carried out in the designed section. For coal seams with a Pugh strength coefficient f value of less than 1.5, directional long boreholes can be constructed in the roof of the coal seams at a close distance, and downward perforations can be shot to carry out volume fracturing. If intensive pre-cracked and crushed operations are performed in interlayers of gangue or subsidence columns, directional long boreholes can be directly constructed in the interlayers of gangue or subsidence columns, and backward intensive pre-cracked operations can be carried out. If pre-cracked and pressure-reducing operations and directional cutting operations are performed in the top and bottom plate rock formations, rock formations with a single layer thickness of more than 5m and a uniaxial compressive strength of more than 40MPa are selected for drilling operations.

[0024] In some embodiments, in step S5, the directional cutting operation adopts a high-pressure jet cutting method, using clean water or sand mixing liquid with a pressure of not less than 60 MPa as the power medium, and ejected at high speed through the nozzle, and the high-pressure drill pipe drives the jet cutter to rotate, thereby completing the jet cutting operation;

[0025] Alternatively, the directional cutting operation adopts a mechanical push cutting method, and a movable push rod is built into the drill rod. After reaching the predetermined position, the tool is slowly opened under the pushing action, and the high-pressure drill rod is used to drive the cutting tool to rotate to complete the mechanical cutting operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a layout diagram of drilling holes in a ground drilling site in the "11N" method suitable for comprehensive prevention and control of coal and rock dynamic disasters in an embodiment of the present invention.

[0027] Figure 2 It is a cross-sectional view of the arrangement of drilling holes in a drilling site set up on the ground in the "11N" method suitable for comprehensive prevention and control of coal and rock dynamic disasters in an embodiment of the present invention.

[0028] Figure 3 This is a drilling arrangement diagram for setting up a drilling site in a horizontal main tunnel in the "11N" method suitable for comprehensive prevention and control of coal and rock dynamic disasters in an embodiment of the present invention.

[0029] Figure 4 This is a drilling arrangement diagram for setting up a drilling site in a main tunnel of a mining area in the "11N" method applicable to comprehensive prevention and control of coal and rock dynamic disasters in an embodiment of the present invention.

[0030] Figure 5 This is a drilling arrangement diagram for setting up a drilling site in a tunneling working face in the "11N" method applicable to comprehensive prevention and control of coal and rock dynamic disasters in an embodiment of the present invention.

[0031] Figure 6This is a drilling arrangement diagram for setting up a drilling site in a mining face tunnel in the "11N" method applicable to comprehensive prevention and control of coal and rock dynamic disasters in an embodiment of the present invention.

[0032] Figure 7 It is a cross-sectional view of the arrangement of drilling holes along the inclination of the working face in the "11N" method suitable for comprehensive prevention and control of coal and rock dynamic disasters in an embodiment of the present invention.

[0033] Figure 8 It is a cross-sectional view of the arrangement of drilling holes along the working face in the "11N" method suitable for comprehensive prevention and control of coal and rock dynamic disasters in an embodiment of the present invention.

[0034] Figure 9 This is a drilling arrangement diagram for setting up a drilling site in a dedicated measures tunnel in the "11N" method applicable to comprehensive prevention and control of coal and rock dynamic disasters in an embodiment of the present invention.

[0035] Figure 10 This is a drilling arrangement diagram for setting up a drilling site in a dedicated chamber in the "11N" method applicable to comprehensive prevention and control of coal and rock dynamic disasters in an embodiment of the present invention.

[0036] Figure 11 It is a cross-sectional schematic diagram of directional long drilling construction in a coal seam in the "11N" method suitable for comprehensive prevention and control of coal and rock dynamic disasters in an embodiment of the present invention.

[0037] Reference numerals:

[0038] Pre-splitting path 1; ground 2; horizontal main tunnel 3; mining area main tunnel 4; excavation working face tunnel 5; mining working face tunnel 6; special measure tunnel 7; special chamber 8. DETAILED DESCRIPTION

[0039] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0040] like Figures 1 to 10 As shown, the "11N" method applicable to the comprehensive prevention and control of coal and rock dynamic disasters in an embodiment of the present invention includes the following steps:

[0041] S1: Determine the location of the coal and rock layer to be pre-cracked, and determine the target layer based on the comprehensive expected effect, the occurrence status of the coal and rock in the treatment area, etc. Generally, hard coal seams with poor natural fracture development, thick interbedded gangue, collapse columns, thick hard rock layers, etc. are selected as target layers. Among them, thick hard rock layers are rock layers with a single layer thickness of more than 5m and a uniaxial compressive strength of more than 40MPa.

[0042] S2: Determine the location of Drill Site 1. The location of Drill Site 1 shall be determined comprehensively based on the development layout of the mining area, the succession of tunnel mining, the construction site conditions, the target layer, the technical parameters of the directional drilling rig, etc. Drill Site 1 shall meet the requirements of directional drilling and mud pump placement, and have the conditions for building a sedimentation tank. The impact of cross-operations shall be avoided, so that one Drill Site 1 can take into account the operational requirements of multiple areas, one tunnel can take into account multiple working faces, and one tunnel can take into account the operational requirements of multiple mining areas.

[0043] S3: Install the high-pressure pump unit. The location of the pump unit should not be too far from drilling site 1, generally no more than 300 meters. Determine the drill hole location and the corresponding pre-splitting paths within the coal stratum to be pre-splitting. Preferably, the pump unit location should be within 50 meters of drilling site 1 to minimize pipeline installation.

[0044] S4: Construction is carried out through directional long drilling technology. Horizontal long boreholes are drilled along the pre-splitting path in the coal and rock layer to be pre-splitting. Directional drilling of long boreholes is carried out along the preset path. The borehole length is generally 100 to 1500 meters, and the borehole diameter is generally 94 to 153 mm.

[0045] S5: Directional cutting is performed on the horizontal long borehole at the location of the coal stratum to be pre-splitting, and a plurality of cutting points are formed in the horizontal long borehole.

[0046] S6: After the horizontal long borehole is drilled, the pre-splitting is performed in a backward segmented pre-splitting manner, and the pre-splitting segment is aligned with the cutting point. After the entire pre-splitting of the horizontal long borehole is completed, the drill is withdrawn.

[0047] S7: Repeat steps S4 to S6 to complete the pre-splitting operation of multiple pre-splitting paths in the coal rock layer to be pre-splitting.

[0048] The "11N" method suitable for comprehensive prevention and control of coal and rock dynamic disasters in the embodiment of the present invention can achieve all-round comprehensive management of high-level thick hard rock layers, medium-level thick hard rock layers, low-level thick hard rock layers, deep mining area surrounding rocks and hard coal seams, and hard bottom plates overlying coal seams, carry out large-scale pre-cracking operations, ensure the pressure relief and permeability enhancement effects of pre-cracking fissures, and at the same time can be used for pumping operations in water-rich layers to achieve safe mining of coal seams at the source, avoid the occurrence of dynamic disasters such as rock burst, coal and gas outbursts, and ensure safe production in coal mine operations.

[0049] In the "11N" method for comprehensive prevention and control of coal and rock dynamic disasters in the embodiment of the present invention, the first "1" refers to a tunnel or an area, that is, it can be one of the horizontal tunnel 3, the mining area tunnel 4, the mining face tunnel 6, and the excavation face tunnel 5, or it can be a special measure tunnel 7 or a special chamber 8, or an area corresponding to the ground 2; the second "1" refers to a set of process technologies, namely, long-distance and large-scale segmented pre-splitting process technologies, including long-hole directional drilling methods, multi-parameter downhole detection methods, and directional drilling. The methods include forward perforation pre-splitting method, backward segmented pre-splitting method, flow control induced pre-splitting method, transient electromagnetic pre-splitting effect inspection method, micro-vibration monitoring filtering and self-positioning method, and mine pressure monitoring method; "N" refers to the selection of drilling site 1 in a tunnel or an area, which can realize all-round comprehensive management of high-level thick hard rock layers, medium-level thick hard rock layers, low-level thick hard rock layers, deep mining area surrounding rocks, hard coal seams, hard floors, and multiple working faces or multiple mining areas in the same horizontal coal and rock layers, and carry out large-scale pre-splitting operations.

[0050] Long-hole directional drilling is based on a directional drilling assembly (DDA), consisting of a kilometer-long directional drilling vehicle, high-strength cable-type drill pipe, a flexible screw motor assembly, and a high-strength drill bit. The kilometer-long directional drilling vehicle is stationed at the drilling site, and the high-strength cable-type drill pipe drives the flexible screw motor assembly to achieve directional drilling. The flexible screw motor assembly consists of an upper connector, a motor assembly, an adjustable bend housing, and a transmission assembly. During operation, the rotor and stator mesh with each other, forming a spiral sealing line and a sealed cavity through their lead difference. As the rotor rotates within the stator, the sealed cavity moves axially, continuously creating and disappearing energy, completing its energy conversion. A safety release is installed between the transmission assembly and the high-strength cable-type drill pipe. If the flexible screw motor assembly or high-strength drill bit components become stuck due to accidents such as hole collapse or misalignment, it ensures smooth disconnection of the high-strength cable-type drill pipe from the flexible screw motor assembly, minimizing losses.

[0051] The multi-parameter while-drilling detection method is implemented based on strain gauges, goniometers, thrust sensors, torque sensors, speed sensors, displacement sensors and high-definition AI cameras. The strain gauges, goniometers and goniometers are placed behind the drill bit and enter the hole through the drill pipe. Multiple sensors and cameras are used to monitor the bottom hole stress environment and drilling parameters in real time during the drilling process.

[0052] Directed perforating pre-splitting is performed using a directional perforator, which is positioned between the front and rear stabilizers. The distance between the two stabilizers is adjusted by a connecting rod. The outer wall of the directional perforator is evenly distributed with jets. This hydraulic gravity-driven perforator operates under the action of shutoff pressure, pushing the directional inner cylinder. The gravity-actuated positioning ball guides the perforator, achieving rotational positioning along the designed direction.

[0053] The backward, staged pre-splitting method utilizes a multi-component pre-splitting assembly, consisting of a ball head, a check valve, a front-end centralizer, a front-end packer, a fracturing device, a rear-end packer, a rear-end centralizer, and a safety release. After drilling is completed as designed, the pre-splitting process begins by pushing the multi-component assembly into the borehole using high-strength, pressure-resistant push rods. The pre-splitting process begins backward, staged, from the bottom of the borehole. Each stage is typically 10 to 30 meters long.

[0054] The flow-controlled induced pre-fracture method is achieved through hydraulic fracturing. This involves using a high-pressure pump set to inject a fracturing fluid of a certain viscosity into the coal formation through a borehole. When the injection flow exceeds the coal formation's absorptive capacity, the coal formation near the bottom of the well will be subjected to tremendous pressure. When the pressure exceeds the rock's tensile strength, the coal formation will break and form cracks. These cracks will then expand with the continued injection of fracturing fluid, thereby increasing the permeability and conductivity of the coal formation. During the fracturing process, the range of the rock pre-fracture network is increased by varying the fracturing pressure and increasing the flow rate, thereby enhancing the hydraulic fracturing effect.

[0055] The transient electromagnetic pre-splitting effect testing method is based on the law of electromagnetic induction. It uses an ungrounded return line or a grounded line source to emit a pulsed magnetic field into the ground. During the pauses in the pulsed magnetic field, a coil or grounding electrode is used to observe the secondary induced eddy current field induced in the underground medium, thereby detecting the medium's resistivity. By measuring the temporal variation of the secondary field at various time periods after power failure, the geoelectric characteristics at different depths are obtained, thereby verifying the pre-splitting effect of the rock formation. During construction, a mining intrinsically safe transient electromagnetic instrument, such as the YCS580 model, can be used, but is not limited to this model. The pre-splitting effect is specifically analyzed through the apparent resistivity imaging results.

[0056] The microvibration monitoring filtering method is an existing technology and a key link in microseismic data processing. It is mainly used to improve the signal-to-noise ratio and reduce the interference of noise on the effective signal. Among them, the filtering method is one of high-pass filtering, low-pass filtering, band-pass filtering and band-stop filtering. The microvibration monitoring self-positioning method refers to the technology of automatically determining the source location through microseismic monitoring data, including the double difference positioning method based on geometric positioning; the inversion positioning based on the waveform characteristics of microseismic waves based on waveform inversion; and the multi-wave joint identification and positioning using the joint comparison and identification of multi-channel waveforms, amplitudes, arrival time differences, etc., to select reasonable waveforms for positioning. In the microvibration monitoring self-positioning method, the automatic, rapid and high-precision positioning of microseismic events is achieved by automatically picking up the arrival time and combining the positioning means of monitoring points.

[0057] Mine pressure monitoring methods can employ at least one of the following: load cell methods, strain gauge methods, mining impact zone prediction methods, and stress sensing technologies. The load cell method measures the magnitude and direction of mine pressure by measuring the tension of load cells, ropes, chains, or rods. The strain gauge method includes two types: line-of-sight strain gauges and strain gauges. Line-of-sight strain gauges measure the surface height and horizontal displacement of rock formations, providing miners with intuitive data on rock deformation. Strain gauges measure internal strain changes, providing a deeper understanding of the stress conditions within the formation. The mining impact zone prediction method is a numerical simulation method based on rock mass mechanics theory and empirical laws. It monitors mine pressure by analyzing the rock mass mechanism and predicting the extent of the mining impact zone. Stress sensing technology is one of the core technologies for mine pressure monitoring. Strain sensors monitor the stress of materials such as rock and gas in the mine, thereby obtaining information on pressure changes. Commonly used stress sensors include strain gauges and pressure sensors. These sensors can be installed in mine tunnels and shafts to monitor pressure changes within the mine in real time. The application of stress sensing technology makes mine pressure monitoring more accurate and reliable.

[0058] Data acquisition and processing technology collects and stores data transmitted by sensors and sends it to a data processor for analysis and processing. Advanced data processing algorithms and software technologies enable rapid analysis, processing, storage, and display of collected data, providing a more convenient and efficient data processing method and enabling a better understanding of pressure changes in mines.

[0059] In some embodiments, in step S2, one of the seven can be selected as the location for setting up the drilling site 1, including the horizontal main tunnel 3, the mining area main tunnel 4, the mining working face tunnel 6, the excavation working face tunnel 5, the special measures tunnel 7, the special chamber 8, and an area corresponding to the ground 2, to ensure efficient and stable drilling pre-cracking work.

[0060] In some embodiments, as Figure 1 and Figure 2 As shown, a drilling site 1 is set on the ground 2, and pre-splitting operations are performed on one or more coal rock layers to be pre-splitting through a single borehole, and horizontal long boreholes are drilled and pre-splitting is performed along multiple pre-splitting paths in a single coal rock layer to be pre-splitting.

[0061] Specifically, the drilling site 1 is set on the ground 2, and extends downward to the coal rock layer to be pre-cracked through a vertical long drill hole according to the drilling position. In the coal rock layer to be pre-cracked, horizontal section drilling is carried out along multiple pre-crack paths, and the rock layer is pre-cracked through multiple horizontal section drilling holes, thereby realizing large-area pre-crack operations with multiple pre-crack paths under single well conditions, and according to the rock layer conditions, the pre-crack operations of multiple coal seams can be taken into account by extending a single drill hole downward.

[0062] In some embodiments, as Figure 3 As shown, the drilling site 1 is set in the horizontal main tunnel 3. In step S4, pre-cracked holes are drilled in multiple mining areas, and the drilling is carried out in an inclined upward direction to the coal rock layer to be pre-cracked. When the working face is perpendicular to the horizontal main tunnel 3 for mining operations, directional long drill holes are constructed in the corresponding pre-cracked rock layer along the extension direction of the working face. The pre-cracked operation of the entire area can be completed during the preparation of the working face, which can effectively avoid the influence of cross-operation, enable the tunnel to be excavated in a low-stress environment, and ensure the excavation speed and size of the tunnel. When the working face is parallel to the horizontal main tunnel 3 for mining operations, the long drill holes simultaneously pass through the rock layers corresponding to the cut eyes, square areas, stop-mining lines, and abnormal structural areas of multiple working faces, implement centralized pre-cracked and advance pretreatment, and optimize the regional stress distribution state.

[0063] In some embodiments, as Figure 4 As shown, the drilling site 1 is set in the main tunnel 4 of the mining area. The drilling site 1 can meet the rock pre-splitting operation requirements of one or two mining areas at the same time. In step S4, drilling pre-splitting is performed on multiple mining areas, and drilling is carried out in an inclined upward direction to the coal and rock layer to be pre-splitting. In the rock layer corresponding to the mining area, a directional long drill hole is constructed along the extension direction of the working face to ensure the pre-splitting effect of the entire coal and rock layer to be pre-splitting, ensure the pressure relief and permeability enhancement effect of the pre-splitting fissures, realize the safe mining of the coal seam at the source, avoid the occurrence of dynamic disasters such as rock burst, coal and gas outburst, and ensure the safe production of coal mine operations.

[0064] In some embodiments, as Figure 5 、 Figure 6 、 Figure 7 and Figure 8 As shown, when the drilling site 1 is set in the tunnel 5 of the excavation working face, the drilling site 1 can simultaneously meet the rock pre-splitting requirements of two or three working faces. When the drilling site 1 is set in the tunnel 6 of the mining working face, the drilling site 1 can simultaneously meet the rock pre-splitting requirements of two or three working faces. In step S4, drilling pre-splitting is performed on multiple working faces. Drilling is performed in an upward, inclined direction to the coal and rock strata to be pre-splitting. For adjacent working faces, directional long drill holes are arranged in the coal and rock strata to be pre-splitting in a direction perpendicular to the extension direction of the working face or in a direction parallel to the extension direction of the working face. When drilling pre-splitting for multiple working faces, directional long drill holes are arranged along the inclination to complete the pre-splitting operation for multiple working faces, which can avoid cross-operation during mining. Directional long drill holes are arranged along the strike to take into account the pre-splitting operations of the corresponding working face and the working face of the next adjacent section, which can avoid cross-operation during mining and facilitate construction.

[0065] In some embodiments, as Figure 9As shown, the drilling site 1 is set in the dedicated measure tunnel 7. The drilling site 1 can meet the rock pre-splitting operation requirements of one or two working faces at the same time. In step S4, drilling pre-splitting is performed on multiple working faces, and drilling is carried out in an inclined upward direction to the coal rock layer to be pre-splitting. Corresponding to the adjacent working face, a directional long drill hole is constructed along the extension direction of the working face.

[0066] In some embodiments, as Figure 10 As shown, the drilling site 1 is set in the chamber. In step S4, with the chamber as the center, the coal and rock layers to be pre-cracked corresponding to the working face cut, the two leading drifts, and the stop-mining line within a radius of 100 to 1500m are pre-cracked to ensure the pre-crack effect of the entire coal and rock layer to be pre-cracked and ensure the safe production of coal mine operations.

[0067] In some embodiments, when arranging the drilling holes, the pre-cracked coal and rock layers are judged. If the coal seam pre-cracked permeability enhancement and directional cutting operations are carried out, for coal seams with a Pugh firmness coefficient f value of 1.6 or above, such as Figure 11 As shown, long directional boreholes can be directly constructed in the coal seam, and directional cutting and high-pressure pre-cracking operations can be carried out in the designed section. For coal seams with a Proctor strength coefficient f value below 1.5, long directional boreholes can be constructed in the roof of the coal seam at a close distance, and perforations can be shot downward to carry out volume fracturing. If intensive pre-cracking and crushing operations are performed in interbedded gangue or subsidence columns, long directional boreholes can be directly constructed in the interbedded gangue layers or subsidence columns to carry out intensive backward pre-cracking. If pre-cracking and pressure relief and directional cutting operations are performed in the top and bottom plate rock formations, rock formations with a single layer thickness of more than 5m and a uniaxial compressive strength of more than 40MPa are selected for drilling operations, and the vertical height of the borehole is controlled not to exceed 200m. Preferably, the vertical height of the borehole is between 30 and 60m.

[0068] In some embodiments, in step S5, the directional cutting operation adopts a high-pressure jet cutting method, using clean water or sand-mixing liquid with a pressure of not less than 60 MPa as the power medium, and ejected at high speed through the nozzle, and the high-pressure drill pipe is used to drive the jet cutter to rotate to complete the jet cutting operation. The structure is simple and easy to operate, and the rapid advancement of the directional cutting operation can be ensured during the construction process.

[0069] In some embodiments, in step S5, the directional cutting operation adopts a mechanical pushing cutting method. A movable push rod is built into the drill rod. After reaching the predetermined position, the tool is slowly opened under the pushing action, and the high-pressure drill rod is used to drive the cutting tool to rotate to complete the mechanical cutting operation. The directional cutting operation is performed by the cutting tool, which facilitates the control of the accuracy and cutting length of the directional cutting operation.

[0070] The "11N" method for comprehensive prevention and control of coal and rock dynamic disasters according to the embodiment of the present invention has the following beneficial effects:

[0071] 1) Through a single tunnel and long-distance, large-scale segmented pre-splitting technology, the coal seam and the overlying high-level thick hard rock layer can be pre-splitting and then weakened, which can exchange space for time and have little impact on mining operations.

[0072] For newly built mines, during the construction period, the long-distance and large-scale segmented pre-splitting technology can be used in the central tunnel to weaken the roof and coal seams in the adjacent planned mining area. This can not only reduce the stress environment in the tunnel area of ​​the construction mining area, but also greatly shorten the preparation time for the first mining working face. For new mining areas, as long as a return mining tunnel is excavated in the mining area, the long-distance and large-scale segmented pre-splitting technology can be used to weaken the thick hard rock layers and coal seams in the roof of the upper and lower working faces to be mined, so that the entire mining area is in a weak roof structure and low-stress mining environment.

[0073] 2) After taking comprehensive measures to control high-level overburden, the cracks in the key layer are fully developed, playing a role similar to an elastic cushion. The load transfer range of the overburden layer is wider, and the dynamic and static loads applied to the coal seam are reduced, thereby reducing the coal seam impact hazard level and the number of warnings, providing a good prerequisite for reducing the pre-unloading, emergency relief and other engineering workload of the surrounding rock in the coal seam mining area.

[0074] 3) The essence of comprehensive pre-treatment of high-level overburden is to pre-crack the key strata to reduce their "framework" effect within the stratum, achieving more uniform and gentle stress transfer within the spatial structure of the overburden, thereby achieving the goal of proactively reducing stress levels in the coal body in the area to be mined. Comprehensive pre-treatment of high-level overburden conforms to the "regional first, local follow-up" anti-bumping strategy and can serve as a new regional anti-bumping measure, an important supplement to local anti-bumping measures.

[0075] 4) Comprehensive management of high-level overburden can reduce the strength and density of tunnel support during excavation and improve excavation efficiency by weakening the roof structure in advance and reducing the basic stress of the coal body; ensure the stability of the tunnel during mining, reduce the workload of tunnel maintenance and reinforcement support; reduce the stress level of the coal body in the mining area, achieve low-stress mining, and increase the mining speed of the working face.

[0076] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0077] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0078] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0079] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0080] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0081] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A method suitable for comprehensive prevention and control of coal and rock dynamic disasters, characterized in that: The following steps are involved: S1: Determine the location of the coal stratum to be pre-splitting; S2: Determine the drilling site location; S3: placing a high-pressure pump group, determining the drilling position and multiple pre-splitting paths corresponding to the drilling holes in the coal rock layer to be pre-splitting; S4: Construction is carried out by using a directional long drilling process, in which a horizontal long borehole is drilled along the pre-splitting path in the coal stratum to be pre-splitting; S5: performing directional cutting operations on the horizontal long borehole in the location of the coal and rock layer to be pre-splitting, and forming multiple cutting points in the horizontal long borehole; S6: After the horizontal long borehole is drilled, the pre-splitting is performed in a backward segmented pre-splitting manner, and the pre-splitting segment is aligned with the cutting point. After the entire pre-splitting of the horizontal long borehole is completed, the drill is withdrawn; The backward staged pre-splitting method is implemented using a multi-combination pre-splitting assembly, which includes a ball head, a one-way valve, a front-end centralizer, a front-end packer, a fracturing device, a rear-end packer, a rear-end centralizer, and a safety release. After the drilling operation is completed as designed, the multi-combination pre-splitting assembly is pushed into the borehole using a high-strength, pressure-resistant push rod. The backward staged pre-splitting begins at the bottom of the borehole, with a single stage length of 10 to 30 meters. S7: repeating steps S4 to S6 to complete the pre-splitting operation of multiple pre-splitting paths in the coal rock layer to be pre-splitting; In step S2, the drilling site is set to one of the following locations: a horizontal main tunnel, a main tunnel in a mining area, a mining face tunnel, a tunneling face tunnel, a dedicated measure tunnel, a dedicated chamber, or an area corresponding to the ground; When arranging drilling holes, the pre-cracked coal and rock strata should be judged. If pre-cracked and permeability-enhancing operations and directional cutting operations are required in coal seams, for coal seams with a Pugh firmness coefficient f value of more than 1.6, long directional drill holes should be directly constructed in the coal seams, and directional cutting and high-pressure pre-cracked operations should be carried out in the designed section. For coal seams with a Pugh firmness coefficient f value of less than 1.5, long directional drill holes should be constructed in the roof of the coal seam at a close distance, and perforations should be shot downward to carry out volume fracturing. If intensive pre-cracked and crushed operations are required in interlayers of gangue or subsidence columns, long directional drill holes should be directly constructed in the interlayers of gangue or subsidence columns, and intensive backward pre-cracked operations should be carried out. If pre-cracked and pressure-reducing operations are required in the top and bottom plate rock strata and directional cutting operations are required, rock strata with a single layer thickness of more than 5m and a uniaxial compressive strength of more than 40MPa should be selected for drilling operations.

2. The method for comprehensive prevention and control of coal and rock dynamic disasters according to claim 1 is characterized in that: The drilling site is set up on the ground, and pre-splitting operations are performed on at least one coal rock layer to be pre-splitting through a single borehole, and horizontal long boreholes are drilled and pre-splitting is performed along multiple pre-splitting paths in the single coal rock layer to be pre-splitting.

3. The method for comprehensive prevention and control of coal and rock dynamic disasters according to claim 1 is characterized in that: The drilling site is set up in the horizontal main tunnel. In step S4, multiple mining areas are pre-cracked by drilling, and the drilling is carried out in an inclined upward direction to the coal rock layer to be pre-cracked. When the working face is perpendicular to the horizontal main tunnel for mining operations, directional long drill holes are constructed in the corresponding pre-cracked rock layer along the extension direction of the working face. When the working face is parallel to the horizontal main tunnel for mining operations, the long drill holes simultaneously pass through the rock layers corresponding to the cutting eyes, square areas, stop-mining lines, and abnormal structural areas of multiple working faces.

4. The method for comprehensive prevention and control of coal and rock dynamic disasters according to claim 1 is characterized in that: The drilling site is set up in the main tunnel of the mining area. In step S4, multiple mining areas are pre-cracked by drilling, and the drilling is carried out in an inclined upward direction to the coal rock layer to be pre-cracked. In the rock layer corresponding to the mining area, a directional long drill hole is constructed along the extension direction of the working face.

5. The method for comprehensive prevention and control of coal and rock dynamic disasters according to claim 1 is characterized in that: The drilling site is set in the tunnel of the excavation working face or the tunnel of the mining working face. In step S4, multiple working faces are pre-cracked by drilling, and the drilling is carried out in an inclined upward direction to the coal and rock layer to be pre-cracked. Corresponding to the adjacent working face, directional long drill holes are arranged in the coal and rock layer to be pre-cracked in a direction perpendicular to the extension direction of the working face or in a direction parallel to the extension direction of the working face.

6. The method for comprehensive prevention and control of coal and rock dynamic disasters according to claim 1 is characterized in that: The drilling site is set up in a special measure tunnel. In step S4, multiple working faces are pre-split by drilling, and the coal rock layer to be pre-split is drilled in an inclined upward direction. Corresponding to the adjacent working face, a directional long drill hole is constructed along the extension direction of the working face.

7. The method for comprehensive prevention and control of coal and rock dynamic disasters according to claim 1 is characterized in that: The drilling site is set up in the chamber. In step S4, with the chamber as the center, the coal and rock layers to be pre-cracked corresponding to the working face cut, the two leading drifts, and the stop-mining line within a radius of 100-1500m are pre-cracked.

8. The method for comprehensive prevention and control of coal and rock dynamic disasters according to claim 1 is characterized in that: In step S5, the directional cutting operation adopts a high-pressure jet cutting method, using clean water or sand mixing liquid with a pressure of not less than 60 MPa as the power medium, and ejected at high speed through the nozzle, and the high-pressure drill pipe drives the jet cutter to rotate to complete the jet cutting operation; Alternatively, the directional cutting operation adopts a mechanical push cutting method, and a movable push rod is built into the drill rod. After reaching the predetermined position, the tool is slowly opened under the pushing action, and the high-pressure drill rod is used to drive the cutting tool to rotate to complete the mechanical cutting operation.

Images