Non-contact drilling hydraulic power and coal gas co-mining method

Abstract

The invention discloses a non-contact type drilling hydraulic power and gas co-mining method. The method comprises the steps that a mixed well is exploited, the horizontal stage and the range of a mining area are determined, and inclined strip mining is adopted in the mining area; a horizontal centralized transportation main roadway is arranged in a stable rock stratum of a coal seam bottom plate at the mining level, and an air return main roadway is arranged in a stable rock stratum of an upper coal seam bottom plate; a plurality of strips are divided between the two main roadways along the inclination direction, a strip uphill is arranged in the middle of each strip along a stable rock stratum below a coal seam bottom plate, and the lower end and the upper end of each strip uphill are communicated with the centralized transportation main roadway and the air return main roadway respectively; drilling a bottom plate of the coal seam, and conveying production equipment into the coal seam from the hole; gas extraction is carried out in a remote control mode; and after gas extraction reaches the standard, hydraulic coal mining is carried out in a remote control mode. According to the method, high-pressure hydraulic cutting can be conducted on the coal seam through the strip uphill floor rock roadway crossing drilling, safe and efficient co-mining of high outburst mine coal and gas is achieved, and mining safety and efficiency are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of coal mining, and in particular relates to a non-contact drilling hydraulic coal-gas co-mining method. Background Art

[0002] Existing coal mining methods include open-pit mining and underground mining. Underground mining includes both dry and wet methods. Currently, coal mining is primarily based on comprehensive mechanization, with developments towards automation and intelligentization. Traditional wet mining, however, is gradually being phased out due to limitations in its applicability. In traditional underground mining methods, the main mining activities of comprehensive mechanized mining are carried out in coal seams. Personnel, mining equipment, and related control systems are in direct contact with coal seams, and the working environment is poor. Especially in gas mines, especially coal and gas outburst mines, the safety of personnel, equipment and systems cannot be effectively guaranteed, and they are still facing the threat of gas disasters. Moreover, this mining method requires stable coal seam occurrence conditions and has poor adaptability to changes in geological conditions. The production system is complex, with many links, large investment and high cost. The existing hydraulic coal mining method also requires personnel and equipment to work directly in the coal seam tunnels. Its main disadvantages include large auxiliary engineering volume, unreliable ventilation system, close contact of operators with exposed coal bodies at the working face, poor safety and reliability, and high gas and coal and gas outburst mines also face greater safety risks. According to statistics, almost all safety accidents in coal and gas outburst mines are related to mining activities carried out in gas outburst dangerous coal seams. Summary of the Invention

[0003] To solve the above problems, the present invention provides a non-contact drilling hydraulic coal-gas co-mining method, which can implement high-pressure hydraulic cutting of coal seams by drilling through the strip uphill bottom rock tunnel, thereby realizing safe and efficient co-mining of coal and gas in high-burst mines, greatly improving mining safety and improving mining efficiency.

[0004] The present invention provides a non-contact drilling hydraulic coal gas co-production method, comprising:

[0005] Develop a mixed well that combines the functions of a main well and an auxiliary well, determine the scope of the horizontal stage and mining area, and adopt an inclined strip mining method within the mining area;

[0006] A horizontal centralized transport tunnel with both main and auxiliary coal transport functions is arranged in the stable rock layer of the mining level coal seam floor, and a return air tunnel is set in the stable rock layer of the upper coal seam floor;

[0007] A plurality of strips are divided along the inclination between the centralized transport tunnel and the return air tunnel, and a strip is arranged uphill along the stable rock layer below the coal seam floor in the middle of each strip, and the lower end and the upper end of the strip are respectively connected to the centralized transport tunnel and the return air tunnel to realize full negative pressure ventilation;

[0008] Drilling a hole in the coal seam floor and sending the production equipment into the coal seam through the hole;

[0009] Using the stable rock formation as a safety barrier, gas extraction is performed by remote control;

[0010] When gas extraction meets the standards, hydraulic mining is carried out using remote control.

[0011] Preferably, in the above-mentioned non-contact drilling hydraulic coal-gas co-mining method, determining the scope of the mining area includes:

[0012] Divide the mining level of the mine, determine the vertical height and stage inclined length of the mining level, and determine the division size of the mining area.

[0013] Preferably, in the above-mentioned non-contact drilling hydraulic coal-gas co-mining method, when arranging the centralized transportation tunnel, it also includes:

[0014] Sets the slope of the water flow from the strip edge toward the center.

[0015] Preferably, in the above-mentioned non-contact drilling hydraulic coal-gas co-mining method, after arranging the strip up the mountain, the method further comprises:

[0016] A coal-water centralized treatment station is set up at the pit bottom yard or the lower part of the mining area or the middle of the centralized transportation tunnel.

[0017] Preferably, in the above-mentioned non-contact drilling hydraulic coal-gas co-mining method, the drilling of the coal seam floor comprises:

[0018] The drilling site is arranged from top to bottom to carry out drilling operations, with the position of the coal bottom plate as the standard. The spacing of each group of drill holes is 8 meters to 15 meters, and the spacing of each drill hole in the group is 8 meters to 15 meters. Each drill hole penetrates the entire thickness of the coal seam to the coal seam roof. After drilling construction, an equilateral triangle-shaped drill hole group is formed in the coal seam.

[0019] Preferably, in the above-mentioned non-contact drilling hydraulic coal-gas co-production method, the following is further included:

[0020] Directional drilling technology and geological radar are used to ensure that the drill holes are evenly distributed within the coal seam according to the designed parameters.

[0021] Preferably, in the above-mentioned non-contact drilling hydraulic coal-gas co-extraction method, the gas extraction by remote control includes:

[0022] After the drilling construction has advanced a certain distance, a remote-controlled water gun sent into the coal seam through the borehole is used to hydraulically flush the seams to extract gas. The gas is extracted into the return air tunnel and transported out of the well using the extraction main pipe. The coal-water mixture produced by hydraulic flushing passes through the borehole and the chute of the strip up the mountain and enters the coal-water centralized treatment station.

[0023] Preferably, in the above-mentioned non-contact drilling hydraulic coal-gas co-extraction method, the hydraulic seam flushing gas extraction includes:

[0024] The high-pressure water jet generated by the remote-controlled water gun is used to punch cracks one by one along the direction of the three adjacent boreholes above the current borehole. By controlling the direction and angle of the remote-controlled water gun, punch cracks are formed between adjacent boreholes from the bottom plate to the top plate of the coal seam, so that the cracks between adjacent boreholes are interconnected, forming an equilateral three-dimensional triangular crack network that is interconnected, so that the coal body forms an equilateral three-dimensional triangular coal stack.

[0025] Preferably, in the above-mentioned non-contact drilling hydraulic coal-gas co-extraction method, the hydraulic seam flushing gas extraction further comprises:

[0026] After the coal body in the extraction strip is hydraulically flushed, a large amount of high-pressure gas adsorbed in the coal body is decompressed and analyzed into free gas, and naturally drifts to the upper part of the strip through the mutually interconnected three-dimensional grid-like flushing channels. When multiple rows of drill holes are drilled and sealed near the top of the return air tunnel at the top of the strip, pre-buried eye extraction pipes are used, and the extraction is connected to the main extraction pipe in the return air tunnel. Multiple groups of extraction pipes are set in the middle and lower part of the strip and connected to the grid.

[0027] Preferably, in the above-mentioned non-contact drilling hydraulic coal-gas co-mining method, the use of remote control to perform hydraulic coal mining includes:

[0028] When the gas extraction meets the standards, hydraulic mining is carried out by using a high-pressure water gun that is delivered into the coal seam through the borehole, and the process is carried out from top to bottom along the strip up the mountain. The high-pressure water jet with a large flow rate ejected by the high-pressure water gun hits and cuts the coal pile, and its large flow rate and hydraulic gradient are used to transport the broken coal out through the hole and the adjacent boreholes. The cut coal-water mixture passes through the borehole and the chute of the strip up the mountain into the coal-water centralized treatment station, and is discharged to the ground by a coal-water pump.

[0029] From the above description, it can be seen that the above-mentioned non-contact drilling hydraulic coal gas co-mining method provided by the present invention includes developing a mixed well with the functions of both the main well and the auxiliary well, determining the scope of the horizontal stage and the mining area, and adopting an inclined strip mining method in the mining area; a horizontal centralized transportation tunnel with both the main coal transportation function and the auxiliary coal transportation function is arranged in the stable rock layer of the coal seam bottom plate at the mining level, and a return air tunnel is set in the stable rock layer of the upper coal seam bottom plate; a plurality of strips are divided along the inclination between the centralized transportation tunnel and the return air tunnel, and a strip is arranged up the mountain along the stable rock layer below the coal seam bottom plate in the middle of each strip, and the strip is arranged up the mountain along the stable rock layer below the coal seam bottom plate. The lower and upper ends of the mountain are respectively connected with the centralized transportation tunnel and the return air tunnel to realize full negative pressure ventilation; holes are drilled in the coal seam bottom plate, and production equipment is sent into the coal seam from the holes; the stable rock layer is used as a safety protection barrier, and gas extraction is carried out by remote control; when the gas extraction meets the standards, hydraulic coal mining is carried out by remote control. It can be seen that there is no need for personnel and equipment to operate in the coal seam. This method can implement high-pressure hydraulic cutting of the coal seam by drilling holes through the strip rock tunnel on the bottom plate of the mountain, thereby realizing safe and efficient co-mining of coal and gas in high-burst mines, greatly improving mining safety and improving mining efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0031] Figure 1 A schematic diagram of an embodiment of a non-contact drilling hydraulic coal-gas co-mining method provided by the present invention;

[0032] Figure 2 A schematic diagram of the mine development project and roadway layout;

[0033] Figure 3 A schematic cross-sectional view of the mine development project and roadway layout;

[0034] Figure 4 A plan view of the drilling layout;

[0035] Figure 5 for Figure 4 Schematic diagram of the AA section in;

[0036] Figure 6 for Figure 4 Schematic diagram of the BB section in . DETAILED DESCRIPTION

[0037] The core of the present invention is to provide a non-contact drilling hydraulic coal-gas co-mining method, which can implement high-pressure hydraulic cutting of coal seams through strip uphill bottom slab rock tunnel through-layer drilling, realize the safe and efficient co-mining of coal and gas in high-burst mines, greatly improve the safety of mining, and improve mining efficiency.

[0038] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0039] The present invention mainly provides a non-contact drilling hydraulic coal gas co-mining method, that is, a strip uphill bottom plate drilling hydraulic coal gas co-mining method, referred to as drilling water mining: starting from the reform of mine development methods and tunnel layout methods, the traditional coal mining and transportation are changed to water mining, water transportation and water lifting, the traditional recovery working face longwall layout is changed to a inclined strip uphill layout, the bottom plate rock is used to go uphill instead of the recovery working face chute coal tunnel, the tunnel and production system layout in the coal seam is cancelled, and production equipment such as high-pressure water guns and monitoring equipment are delivered to the coal seam through bottom plate rock drilling, the bottom plate rock layer is used as a safety protection barrier, and non-contact gas extraction and coal mining are realized by remote control operation, opening up a new path for coal mines to achieve inherently safe mining.

[0040] The embodiment of the non-contact drilling hydraulic coal gas co-mining method provided by the present invention is as follows: Figure 1 As shown, Figure 1 This is a schematic diagram of an embodiment of a non-contact drilling hydraulic coal-gas co-production method provided by the present invention. The method may include the following steps:

[0041] S1: Develop a mixed well that combines the functions of the main well and auxiliary well, determine the scope of the horizontal stage and mining area, and adopt an inclined strip mining method within the mining area;

[0042] It should be noted that this mining plan uses water mining, water transportation, and water lifting. Coal and water lifting pipelines can be laid through auxiliary shafts or ground drillings. Therefore, the main shaft and its supporting lifting system can be eliminated, that is, only a mixed shaft is required to meet the requirements. This mixed shaft can be a vertical shaft or an inclined shaft, which can be selected according to actual needs. In addition, determining the scope of the mining area can specifically include: dividing the mining level of the mine, determining the vertical height and stage inclined length of the mining level, and determining the division size of the mining area. In a specific example, the horizontal vertical height is preferably 100 meters to 300 meters, and the stage inclined length is preferably 500 meters to 800 meters. It should be noted here that a stage is a block section divided along a certain elevation within a coal mine field. A stage is further divided into several mining areas. An independent mining unit equipped with a complete set of safe water mining systems is called a mining area. The strike length of a single wing of the mining area should not exceed 1500 meters, and the strike length of two wings should be 2000 meters to 2500 meters.

[0043] S2: A horizontal centralized transport tunnel with both main and auxiliary coal transport functions is arranged in the stable rock layer of the mining level coal seam floor, and a return air tunnel is set in the stable rock layer of the upper coal seam floor;

[0044] For details, please refer to Figures 2 to 6 , Figure 2 This is a schematic diagram of the mine development project and tunnel layout. Figure 3 This is a cross-sectional diagram of the mine development project and tunnel layout. Figure 4 This is a plan view of the drilling arrangement. Figure 5 for Figure 4 Schematic diagram of the AA section in Figure 6 for Figure 4 Schematic diagram of the BB section in Figure 2 A mixed vertical shaft development method is demonstrated in which a mixed vertical shaft and a shaft bottom parking lot are set up in the middle of the mining area. The horizontal centralized transportation and return air tunnel can also be used as the central mining area transportation and return air tunnel. Figure 2 The left side shows the forward mining method, and shows the relationship between strip division, main tunnel, uphill excavation, drilling, gas extraction and water mining working face. Figure 2 The right side shows the retreat mining method, and shows the strip bottom rock uphill excavation, drilling construction strip, gas extraction strip, mining operation strip and strip goaf area, and also shows the location of the strip boundary line. Figure 3 It shows the second level transport tunnel, the first level transport tunnel, the pit bottom parking lot, the first level return air uphill and the first level return air tunnel below the main mining seam, as well as the return air shaft and the mixed vertical shaft. Figure 4 The strip uphill and strip boundary between the horizontal transport tunnel and the horizontal return air tunnel are shown, as well as the positions of the various boreholes arranged on the strip uphill. It can be seen that three adjacent boreholes can be arranged into a three-dimensional equilateral triangle.Figure 5 From the AA section shown, in the rock layer below the coal seam, multiple boreholes were arranged along the strip between the horizontal transport tunnel and the horizontal return air tunnel. Figure 6 The strip uphill and strip boundary below the coal seam are shown, with the drill holes at points O, a, b, c, d, A, B, C, D, and E on the BB section.

[0045] It should be noted that underground transportation in coal mines is divided into main transportation (generally using belt conveyors to transport coal) and auxiliary transportation (transporting materials, equipment, personnel, etc.). A centralized transportation tunnel means that all transportation is concentrated in one tunnel. In this case, the main coal transportation is replaced by the ditches or pipelines in the centralized transportation tunnel, and the belt conveyor coal transportation system is cancelled. This centralized transportation tunnel generally serves as an air intake tunnel, and the return air tunnel refers to a tunnel mainly used for return air (usually gas extraction pipes, water supply and drainage pipes, etc. are also installed). The centralized transportation tunnel on the upper level can be used as the return air tunnel on the next level. A key point of this plan is that it no longer designs tunnels along the coal seam as in the existing technology, but arranges all development, mining tunnels and other well and tunnel projects in stable rock formations 10 to 30 meters away from the bottom of the coal seam, completely avoiding the many safety risks and disaster hazards caused by mining and other activities in the coal seam, and at the same time avoiding the huge investment in coal uncovering and tunnel maintenance projects.

[0046] S3: Multiple strips are divided along the inclination between the centralized transport tunnel and the return air tunnel. In the middle of each strip, a strip is arranged along the stable rock layer below the coal seam floor. The lower and upper ends of the strip are respectively connected to the centralized transport tunnel and the return air tunnel to achieve full negative pressure ventilation;

[0047] Specifically, the plan eliminates the mining area preparation tunnel, and rock can be arranged uphill (i.e., strip uphill) along the stable rock layer strip of 15 to 25 meters on the coal seam floor between the horizontal (mining area) transport tunnel and the return air tunnel. The spacing of the strip uphill arrangement can be 80 to 90 meters, and the strip uphill arrangement can be forward (advancing from the center of the mining area to the boundary of the mining area) or backward (advancing from the boundary of the mining area to the center of the mining area).

[0048] S4: Drill a hole in the coal seam floor and send the production equipment into the coal seam through the hole;

[0049] The steps of drilling holes in the coal seam floor may specifically include: arranging a drilling site from top to bottom to implement drilling operations. The drilling site and drilling layout and parameters can refer to the traditional hydraulic funnel method for coal mining, and are designed accordingly in combination with the coal seam and gas occurrence conditions. The specific arrangement and parameters of the drilling holes may be as follows: based on the position of the coal bottom plate seen by the drilling holes, the spacing of each group of drilling holes in the plane is 8 meters to 15 meters, and the spacing of each drilling hole in the group is also 8 meters to 15 meters. Each drilling hole penetrates the full thickness of the coal seam to the coal seam roof. After the drilling construction, an equilateral triangle-shaped drilling hole group is formed in the coal seam. For details, please refer to Figure 4 . Furthermore, the bottom plate drilling holes must ensure that "one hole has multiple uses" to create conditions for efficient gas extraction and coal mining. In the early gas extraction and later hydraulic coal mining, remote-controlled water guns are sent into the coal seam through drilling to implement hydraulic flushing or hydraulic cutting of coal. The drilled holes also serve as channels for water mining equipment, water supply pipelines, control pipelines and coal-water mixture gravity flow channels. Directional drilling technology and geological radar can be used to ensure that the drilled holes are evenly arranged in the coal seam according to design parameters.

[0050] S5: Using stable rock formations as a safety barrier and remotely controlling gas extraction;

[0051] It should be noted that this plan adopts the "inclined strip" mining method. Based on the principle of "treatment first, then mining, extraction first, then mining", it rationally arranges the "extraction" and "mining" succession. Gas extraction and hydraulic coal mining are carried out in strips in sequence. In the early stage, "extraction first" is mainly for gas control, and in the later stage, "main mining" is mainly for coal mining to better ensure safety.

[0052] S6: When gas extraction meets the standards, hydraulic mining is carried out using remote control.

[0053] From the above description, it can be seen that in the embodiment of the above-mentioned non-contact drilling hydraulic coal gas co-mining method provided by the present invention, since it includes developing a mixed well with the functions of both the main well and the auxiliary well, the scope of the horizontal stage and the mining area is determined, and an inclined strip mining method is adopted in the mining area; a horizontal centralized transportation tunnel with both the main coal transportation function and the auxiliary coal transportation function is arranged in the stable rock layer of the mining horizontal coal seam bottom plate, and a return air tunnel is set in the stable rock layer of the upper coal seam bottom plate; a plurality of strips are divided between the centralized transportation tunnel and the return air tunnel, and a strip is arranged up the mountain in the middle of each strip along the stable rock layer below the coal seam bottom plate, and the strip is arranged up the mountain along the stable rock layer below the coal seam bottom plate. The lower and upper ends of the mountain are respectively connected with the centralized transportation tunnel and the return air tunnel to realize full negative pressure ventilation; holes are drilled in the coal seam floor, and production equipment is sent into the coal seam from the holes; stable rock formations are used as a safety protection barrier, and gas extraction is carried out by remote control; when the gas extraction meets the standards, hydraulic mining is carried out by remote control. It can be seen that there is no need for personnel and equipment to operate in the coal seam. This method can implement high-pressure hydraulic cutting of the coal seam by drilling holes through the strip rock tunnel on the bottom of the mountain, thereby realizing the safe and efficient co-mining of coal and gas in high-burst mines, greatly improving the safety of mining and improving mining efficiency.

[0054] In a specific embodiment of the non-contact drilling hydraulic coal-gas co-production method, the layout of the centralized transport tunnel may also include: establishing a water flow slope from the strip boundary to the center. Specifically, the horizontal centralized transport tunnel should have a certain water flow slope from the boundary to the center (toward the bottom of the well), and auxiliary transport should use a monorail crane or endless rope winch.

[0055] In another specific embodiment of the non-contact drilling hydraulic coal-gas co-mining method, based on the above specific embodiment, after the strips are arranged up the mountain, the following steps may be further included:

[0056] A coal-water centralized treatment station is set up in the pit yard or the lower part of the mining area or in the middle of the centralized transport tunnel. It should be noted here that when the mining area is long, a coal-water treatment station can be set up in the middle of the transport tunnel as needed. This can be selected according to actual needs and is not limited here.

[0057] In another specific embodiment of the non-contact drilling hydraulic coal-gas co-extraction method, gas extraction by remote control may specifically include:

[0058] After the drilling construction has advanced a certain distance, a remote-controlled water gun sent into the coal seam through the borehole is used to hydraulically flush the seams to extract gas. The gas is extracted into the return air tunnel using the extraction main pipe and transported to the outside of the well. The coal-water mixture produced by the hydraulic flushing passes through the borehole and the chute that goes up the mountain in strips and enters the coal-water centralized treatment station. It should be noted that the remote-controlled water gun used here is a special equipment for hydraulic flushing of high-burst coal seams and hydraulic coal mining by drilling. It can be composed of a water gun assembly, supporting equipment and pipelines, a remote control system, etc. During installation, the water gun assembly can be sent into the drilled coal seam using a drilling rig, and then connected to external supporting equipment such as high-pressure water supply pipelines and pump stations, remote monitoring and operation control platforms, etc. The control platform can realize the functions of orientation, adjustment, rotation, injection, cutting, etc. of the water gun in the coal seam, and the monitoring of the hydraulic flushing and cutting of the coal body and the adjustment of the working parameters can be realized through the signal transmission of the monitoring probe.

[0059] Furthermore, the above-mentioned step of hydraulically flushing gas extraction may also include:

[0060] After the drilling construction has advanced a certain distance, hydraulic flushing can be carried out to extract gas. The remote-controlled water gun used for flushing is delivered into the coal seam through the bottom plate drill hole. The high-pressure water jet generated by the remote-controlled water gun is used to flush the seams one by one along the direction of the three adjacent boreholes above the drill hole. By controlling the direction and angle of the remote-controlled water gun, flushing seams are formed between adjacent boreholes from the bottom plate to the top plate of the coal seam, so that the seams between adjacent boreholes are interconnected, forming an interconnected equilateral three-dimensional triangular seam network, and forming an equilateral three-dimensional triangular coal pile in the coal body. By optimizing the design of drilling layout and flushing parameters, the distance from all solid coal within the hydraulic flushing control range to the free surface of the seam is less than its extraction radius, thereby maximizing the release of coal body gas pressure (sufficient pressure relief), increasing the permeability of the coal seam, and allowing the coal body gas to be fully resolved and released, thereby achieving the goal of "extracting as much as possible."

[0061] Furthermore, the above-mentioned step of hydraulically flushing gas extraction may further include:

[0062] To ensure effective extraction, the boreholes should be temporarily sealed after hydraulic blasting is completed and the water guns are removed to prevent air leakage. After hydraulic blasting, the coal within the extraction zone is decompressed and released as free gas, which naturally drifts upward through the interconnected three-dimensional grid of blasting channels. Pre-embedded blasting pipes are installed near the top of the return air tunnel in the uppermost section of the zone during blasting. These pipes are connected to the main extraction and discharge pipes within the return air tunnel for extraction. Multiple groups of blasting pipes are installed in the middle and lower sections of the zone and connected to the grid to improve extraction efficiency. Because the blasting channels within the coal bodies of each borehole are interconnected, a three-dimensional grid of gas migration channels is formed. Under the negative pressure of the mine extraction system, and by leveraging the upward drift of gas and the downward diversion of coal and water, gas extraction is effectively improved. To ensure construction safety, during hydraulic blasting operations within the boreholes, blowout preventers are installed at the borehole openings and connected to the main blowout preventer pipes within the return air tunnel. The coal-water mixture produced by hydraulic flushing enters the centralized (mining area) transport tunnel coal-water pool through the drill hole and uphill chute, and is discharged to the mining area or the bottom of the well by the slurry pump.

[0063] In a preferred embodiment of the non-contact drilling hydraulic coal-gas co-mining method, based on the above embodiment, the hydraulic coal mining by remote control can specifically include the following safe and efficient hydraulic coal mining process:

[0064] After the strip gas extraction meets the standards, hydraulic mining is carried out using high-pressure water guns delivered into the coal seam through boreholes. This is done from top to bottom along the strip, using a funnel-type mining method. Because the coal body has been cut into equilateral triangular strips (commonly known as coal piles) during the early hydraulic seam flushing, a funnel is first flushed out at the return air tunnel drilled at the top of the strip. Then, coal piles are flushed one by one from both wings of the strip toward the center. The high-flow high-pressure water jets ejected by the high-pressure water guns hit and cut the coal piles, while the high flow rate and hydraulic gradient are used to transport the broken coal and discharge it through the hole and adjacent boreholes. Unlike the early gas flushing, a larger flow rate is required to flush and transport the coal during coal mining. The cut coal-water mixture enters the coal-water centralized treatment station through the borehole and the chute leading up the strip, and is discharged to the surface by a coal-water pump.

[0065] It should also be noted that the roof management method for this drilled hydraulic mining operation is the same as that used in traditional hydraulic mining, employing an unsupported natural caving method. By rationally selecting mining parameters and the order in which the caving takes place, adjusting the jet parameters, and continuously summarizing experience and training operators, we can effectively control the area and duration of the roof overhang on the working face, thereby minimizing damage to the water guns by large coal lumps or falling gangue from the roof. Drilled hole blockages must be promptly cleared, and the methods must be refined through understanding the patterns and practices in production.

[0066] During hydraulic mining, a small amount of residual gas overflows from the coal pile. Under the dual effects of the upward drift of the gas and the pre-buried extraction negative pressure at the upper end of the strip, it drifts upward along the goaf and is pumped to the ground through the extraction hole connected to the return air tunnel extraction main pipe at the upper part of the strip.

[0067] The method provided by the present application is essentially different from the traditional hydraulic coal mining method. The strip uphill bottom plate drilling hydraulic coal mining method overcomes almost all the shortcomings of traditional hydraulic coal mining, such as large excavation engineering volume, imperfect ventilation system, and unsafe operators. Moreover, the system adopted is simple, with fewer processes, fewer people, high work efficiency, low energy consumption, small investment, and quick results. Especially in the entire process of gas control and coal mining, the operators are remotely controlled and have no direct contact with the coal seam. The bottom plate rock is a natural protective wall, and safe production is reliably guaranteed. This method is an effective way to achieve safe and efficient production in mines with coal and gas outburst hazards and other mines with suitable conditions.

[0068] The optimization of the production safety system includes the following aspects:

[0069] 1. Gas extraction system: The main pipeline of the gas extraction and blowout prevention system is laid along the upper return air tunnel, and the main pipeline is laid along the strip up the mountain. Before drilling, hydraulic flushing and cutting of each borehole, a blowout prevention device is installed at the hole mouth and connected to the blowout prevention main pipeline.

[0070] 2. Coal Hoisting System: A water-based mining, water-transportation, and water-lifting design significantly simplifies the mine's main transportation and hoisting systems. Coal-water pools and slurry pumps are installed in the centralized transport tunnels at the uphill and downhill entrances of each strip. The coal-water mixture, which flows down from hydraulic blasting and mining operations, enters the coal-water pool in the transport tunnels through the drilled holes and the strip uphill chutes. Slurry pumps pump the mixture to the mining area or the centralized coal-water treatment station at the bottom of the mine. The mixture is then pumped by high-lift, high-flow coal-water pumps from the mine's main hoisting system to the raw coal pools at the surface coal washing plant for washing.

[0071] 3. High-pressure water system: This is the main production system of this sub-scheme, which consists of a high-pressure water pump group, water supply pipelines and their accessories. The high-pressure pump group can be installed on the ground or in an underground coal-water centralized treatment station. The water source can be supplemented by mine water, underground circulating water or return water from the ground coal washing plant.

[0072] 4. Auxiliary hoisting and transportation, mine ventilation, power supply, drainage, compressed air, monitoring, communications, and personnel positioning systems: All auxiliary production systems can essentially continue to use their existing methods. Since the mine does not require excavation within the coal seam and conveyor belt transport, installation, and recovery, the workload and investment of auxiliary production systems are significantly reduced, as is the number of underground workers. This reduces the number of personnel, improves mine efficiency, safety, and achieves significant environmental and energy savings. For mines with large water inflows, this solution can integrate the mine drainage system, high-pressure water supply system, and coal-water hoisting system, reducing or even eliminating surface water replenishment, resulting in greater energy conservation and environmental protection.

[0073] The following conditions must be met to achieve better results:

[0074] 1. Coal seam occurrence conditions: gently inclined, inclined and steeply inclined coal seams with an inclination of more than 5°. The coal seams are relatively soft in hardness, mainly composed of fine coal, and do not contain thick layers of interbedded gangue. They have strong adaptability to large changes in coal thickness and are very beneficial for the mining of close-range coal seam groups.

[0075] 2. The rock properties of the coal seam roof and floor are good: the roof is relatively complete and stable, and basically does not fall off before the small coal pile is mined. The floor does not become muddy or bulge when it comes into contact with water. There are stable or relatively stable rock layers within 10 to 30 meters of the coal seam floor.

[0076] 3. This scheme is mainly used in high-gas mines and coal and gas outburst mines. It can also be promoted and applied in low-gas mines with suitable conditions and mines with unstable coal seams. It is especially suitable for mines with large water inflow, large dust volume and high ground temperature.

[0077] 4. This scheme can be applied to large, medium and small mines that are newly built or expanded and renovated under suitable conditions.

[0078] This method utilizes floor drilling and hydraulic sluicing, along with specialized hydraulic coal mining equipment—specifically, high-flow, high-pressure, remotely controlled water guns and their associated equipment. Furthermore, this primary coal production system utilizes water mining, water transportation, and water pumping, optimizing mine development, roadway layout, production, and auxiliary systems. This significantly simplifies production and auxiliary processes, reduces mine investment and maintenance costs, and reduces labor, effectively lowering production costs. This solution utilizes a more scientific and rational design of floor drilling parameters: an equilateral triangle grid arrangement. Directional drilling and geological radar ensure uniform placement of boreholes within the coal seam according to designed parameters. This optimizes the hydraulic sluicing process, effectively improving gas extraction effectiveness. Furthermore, this approach leverages the laws of gas migration and mine pressure to mitigate major risks and potential hazards in coal mines. The rational design of drilling and hydraulic mining processes and parameters ensures safe and efficient mining. Floor drilling and hydraulic sluicing within the coal seam are critical to safe production, necessitating the reliability of the orifice blowout preventer (BOP) and the mine's blowout prevention system.

[0079] In summary, the above solution provided by this application has the following advantages:

[0080] (1) The implementation of strip uphill floor drilling hydraulic coal gas (gas) co-mining is a new method of non-direct contact gas control and coal mining in high gas outburst (high outburst) coal seams. It avoids the various safety risks and disaster hazards of traditional methods of coal excavation and mining in coal seams, and creates a new way to safely mine high outburst coal seams. Fundamentally improve the safe production and working environment of coal mines: the main mining activities in coal and gas outburst dangerous mines are not carried out in the coal seam, but through the floor rock lanes and drilling holes, using high-pressure water jets sprayed by remote-controlled water guns to cut the coal body for gas control and coal mining, realizing non-direct contact operations with the coal seam, and using the coal seam floor rock pillars to provide safety protection for underground workers and equipment, thereby achieving safe and efficient production.

[0081] (2) This plan eliminated the preparation tunnels in the mining area, the coal tunnels at the mining face, and the traditional coal mining face and its large-scale equipment through the optimization of mine development, tunnel layout and production system. Instead, it adopted the method of hydraulic coal (gas) mining by drilling holes in the bottom rock tunnel strips uphill, which greatly simplified the production system, reduced the total investment of the mine by more than 40%, and reduced the production cost by more than 50%.

[0082] (3) The use of high-pressure water jets to flush seams is the key to efficient gas control in this solution and is also its most important feature. Water mining through drilling achieves unmanned operation of the coal face through remote control, completely overcoming the shortcomings of traditional water mining, achieving safe and efficient production, and effectively improving the recovery rate. This has opened up new avenues for the promotion and application of water mining technology and laid a solid foundation for the construction of intelligent mines.

[0083] (4) In coal seams with coal and gas outburst hazards, high-pressure water jets are used to implement multi-faceted crack punching of the coal body to form multi-faceted three-dimensional cracks and holes, and the adjacent drilled cracks and holes are interconnected to form a three-dimensional crack and hole network that is interconnected. This can maximize the analysis of coal body adsorption of gas and the multi-channel migration of free gas, so as to achieve "extraction as much as possible".

[0084] (5) Since the coal tunnels have been eliminated in the entire mine and all rock tunnels are used, the coal pillars in the uphill and downhill mining areas and the large tunnels can be eliminated, realizing the coal pillar-free mining in the mine and effectively improving the resource recovery rate of the mine.

[0085] (6) The application of this technology is beneficial to improving the underground working environment of coal mines, reducing production links, alleviating the labor intensity of miners, preventing dust, spontaneous combustion, impact ground pressure, geothermal, roof accidents, electromechanical transportation accidents, etc., and the safety production reliability of mines is significantly improved.

[0086] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A non-contact drilling hydraulic coal gas co-mining method, characterized in that: include: Develop a mixed well that combines the functions of a main well and an auxiliary well, determine the scope of the horizontal stage and mining area, and adopt an inclined strip mining method within the mining area; A horizontal centralized transport tunnel with both main and auxiliary coal transport functions is arranged in the stable rock layer of the mining level coal seam floor, and a return air tunnel is set in the stable rock layer of the upper coal seam floor; A plurality of strips are divided along the inclination between the centralized transport tunnel and the return air tunnel, and a strip uphill is arranged in the middle of each strip along the stable rock layer below the coal seam floor, and the lower end and the upper end of the strip uphill are respectively connected with the centralized transport tunnel and the return air tunnel to realize full negative pressure ventilation; Drilling a hole in the coal seam floor and sending the production equipment into the coal seam through the hole; Using the stable rock formation as a safety barrier, gas extraction is performed by remote control; When gas extraction meets the standards, hydraulic mining is carried out using remote control.

2. The non-contact drilling hydraulic coal gas co-mining method according to claim 1, characterized in that: The scope of the mining area to be determined includes: Divide the mining level of the mine, determine the vertical height and stage inclined length of the mining level, and determine the division size of the mining area.

3. The non-contact drilling hydraulic coal gas co-mining method according to claim 2, characterized in that: When arranging the centralized transport tunnel, it also includes: Sets the slope of the water flow from the strip edge toward the center.

4. The non-contact drilling hydraulic coal gas co-mining method according to claim 3, characterized in that: After arranging the strips up the mountain, the method further includes: A coal-water centralized treatment station is set up at the pit bottom yard or the lower part of the mining area or the middle of the centralized transportation tunnel.

5. The non-contact drilling hydraulic coal gas co-mining method according to claim 4, characterized in that: The drilling of the coal seam floor comprises: The drilling site is arranged from top to bottom to carry out drilling operations, with the position of the coal bottom plate as the standard. The spacing of each group of drill holes is 8 meters to 15 meters, and the spacing of each drill hole in the group is 8 meters to 15 meters. Each drill hole penetrates the entire thickness of the coal seam to the coal seam roof. After drilling construction, an equilateral triangle-shaped drill hole group is formed in the coal seam.

6. The non-contact drilling hydraulic coal gas co-mining method according to claim 5, characterized in that: Also includes: Directional drilling technology and geological radar are used to ensure that the drill holes are evenly distributed within the coal seam according to the designed parameters.

7. The non-contact drilling hydraulic coal gas co-mining method according to claim 6, characterized in that: The gas extraction by remote control includes: After the drilling construction has advanced a certain distance, a remote-controlled water gun sent into the coal seam through the borehole is used to hydraulically flush the seams to extract gas. The gas is extracted into the return air tunnel and transported out of the well using the extraction main pipe. The coal-water mixture produced by hydraulic flushing passes through the borehole and the chute of the strip up the mountain and enters the coal-water centralized treatment station.

8. The non-contact drilling hydraulic coal gas co-mining method according to claim 7, characterized in that: The hydraulic crack flushing gas extraction method includes: The high-pressure water jet generated by the remote-controlled water gun is used to punch cracks one by one along the direction of the three adjacent boreholes above the current borehole. By controlling the direction and angle of the remote-controlled water gun, punch cracks are formed between adjacent boreholes from the bottom plate to the top plate of the coal seam, so that the cracks between adjacent boreholes are interconnected, forming an equilateral three-dimensional triangular crack network that is interconnected, so that the coal body forms an equilateral three-dimensional triangular coal stack.

9. The non-contact drilling hydraulic coal gas co-mining method according to claim 8, characterized in that: The hydraulic crack flushing gas extraction method further includes: After the coal body in the extraction strip is hydraulically flushed, a large amount of high-pressure gas adsorbed in the coal body is decompressed and analyzed into free gas, and naturally drifts to the upper part of the strip through the mutually interconnected three-dimensional grid-like flushing channels. When multiple rows of drill holes are drilled and sealed near the top of the return air tunnel at the top of the strip, pre-buried eye extraction pipes are used, and the extraction is connected to the main extraction pipe in the return air tunnel. Multiple groups of extraction pipes are set in the middle and lower part of the strip and connected to the grid.

10. The non-contact drilling hydraulic coal gas co-mining method according to claim 9, characterized in that: The hydraulic coal mining by remote control method includes: When the gas extraction meets the standards, hydraulic mining is carried out by using a high-pressure water gun that is delivered into the coal seam through the borehole, and the process is carried out from top to bottom along the strip up the mountain. The high-pressure water jet with a large flow rate ejected by the high-pressure water gun hits and cuts the coal pile, and its large flow rate and hydraulic gradient are used to transport the broken coal out through the hole and the adjacent boreholes. The cut coal-water mixture passes through the borehole and the chute of the strip up the mountain into the coal-water centralized treatment station, and is discharged to the ground by a coal-water pump.

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