阅读说明：本技术 基于一次成孔的大直径钻孔时空协调抽采瓦斯方法 (Large-diameter borehole space-time coordination gas extraction method based on primary pore-forming ) 是由 王壮 赵宝友 张立新 肖辉瓒 王跃润 于 2021-10-18 设计创作，主要内容包括：本发明公开了基于一次成孔的大直径钻孔时空协调抽采瓦斯方法,由本工作面回风巷侧邻近工作面的措施巷向回风巷打设大直径钻孔,使用多级组合钻头、大直径螺旋钻杆及钻机完成一次成孔作业。将高强负压大直径护管推入大直径钻孔内,封孔后将其接入瓦斯抽采管路；大直径钻孔超前工作面连接负压风筒抽采上隅角瓦斯,滞后工作面抽采采空区瓦斯,根据实时监测管路内瓦斯抽采数据,调整大直径钻孔抽采时机,形成大直径钻孔时空协调抽采采空区及上隅角瓦斯的抽采系统。本发明可实现大直径钻孔一次成孔,提高钻孔效率；同时,利用本发明形成的时空协调抽采系统能够高效防治上隅角瓦斯超限,且能够减少钻孔数量,降低施工成本。(The invention discloses a large-diameter drilling hole space-time coordination gas extraction method based on primary hole forming. Pushing the high-strength negative-pressure large-diameter protective pipe into the large-diameter drill hole, and connecting the protective pipe into a gas extraction pipeline after hole sealing; and the leading working face of the large-diameter drill hole is connected with a negative pressure air duct to extract gas at the upper corner, the lagging working face is used for extracting gas at the goaf, and the extraction time of the large-diameter drill hole is adjusted according to gas extraction data in the real-time monitoring pipeline, so that the extraction system for extracting gas at the goaf and the upper corner in a time-space coordinated manner in the large-diameter drill hole is formed. The invention can realize the one-time pore forming of the large-diameter drilling hole and improve the drilling efficiency; meanwhile, the space-time coordination extraction system formed by the method can be used for efficiently preventing the gas at the upper corner from exceeding the limit, reducing the number of drilled holes and lowering the construction cost.)

1. The large-diameter borehole space-time coordination gas extraction method based on primary pore-forming is characterized by comprising the following steps of:

the method comprises the following steps: drilling a large-diameter drill hole from a measure roadway adjacent to the working surface on the side of the return airway to the return airway, wherein the large-diameter drill hole penetrates through the protective coal pillar; completing one-time hole forming operation by using a multi-stage combined drill bit, a large-diameter spiral drill rod and a drilling machine;

step two: pushing the high-strength negative-pressure large-diameter protective pipe into the large-diameter drill hole from the measure roadway by using a drilling machine to complete the installation operation of the protective pipe;

step three: sealing the large-diameter drill hole, wherein the sealing length of the two ends is more than one third of the total length of the large-diameter drill hole; after hole sealing is completed, mounting a double-eccentric butterfly valve and a gas drainage multi-parameter sensor at the exposed end of the high-strength negative-pressure large-diameter protective pipe at one end of the measure roadway, and connecting the double-eccentric butterfly valve and the gas drainage multi-parameter sensor into a gas extraction pipeline;

step four: in the return airway, connecting high-strength negative-pressure large-diameter protective pipes in large-diameter drill holes of the leading working face with a negative-pressure air duct respectively, suspending the negative-pressure air duct on the airway wall, extending the negative-pressure air duct to the upper corner position, and continuously extracting gas at the upper corner; directly extracting gas in the goaf by the large-diameter drill hole of the lagging working face to form a space extraction pipeline; and monitoring gas extraction data in a single large-diameter drill hole in real time, wherein the gas extraction data comprises extraction mixing amount and gas concentration, monitoring the gas concentration of an upper corner in real time, and adjusting the extraction time of the large-diameter drill hole in real time according to the monitoring data to form a large-diameter drill hole time-space coordinated extraction system.

2. The primary pore-forming based large-diameter borehole space-time coordination gas extraction method according to claim 1, characterized by comprising the following steps: the multi-stage combined drill bit in the first step comprises a guide drill bit, a guide drill rod and a multi-stage hole expanding drill bit, wherein the multi-stage hole expanding drill bit comprises at least two hole expanding drill bits with different diameters, including a first-stage hole expanding drill bit and a second-stage hole expanding drill bit; the one-time pore-forming drilling method for large-diameter drilling in the first step comprises the following steps: firstly, a guide drill bit, a guide drill rod, a multi-stage hole expanding drill bit and a large-diameter spiral drill rod are connected in sequence, a large-diameter drill hole is drilled from a measure roadway to a return airway in cooperation with a drilling machine, and when the guide drill bit is completely exposed in the return airway, drilling is stopped; detaching the guide drill bit in the return airway, continuing drilling, and stopping drilling when the primary reamer bit is completely exposed in the return airway; and repeating the operation until all the reaming bits are completely disassembled, and finally, completing the operation of withdrawing the drilling rod in the measure roadway.

3. The primary pore-forming based large-diameter borehole space-time coordination gas extraction method according to claim 1, characterized by comprising the following steps: in the fourth step, when the gas concentration of the upper corner exceeds the upper limit of the designed safety threshold, the extraction quantity and the extraction negative pressure of the large-diameter drill holes of the leading working face are increased, and the extraction negative pressures of a plurality of large-diameter drill holes which are the lagging working face and are closest to the working face are increased; when the gas concentration of the upper corner is lower than the lower limit of the designed safety threshold, reducing the extraction quantity of the large-diameter drill holes of the advanced working face or reducing the extraction negative pressure or reducing the extraction quantity of the large-diameter drill holes of the advanced working face and reducing the extraction negative pressure; when the extraction mixing amount and the gas concentration in the large-diameter drill hole of the lagging working face exceed the upper limit of a designed safety threshold, starting a plurality of large-diameter drill holes near the large-diameter drill hole to extract gas in the goaf, and increasing the extraction negative pressure of the large-diameter drill hole and the plurality of large-diameter drill holes near the large-diameter drill hole; when the extraction mixing amount and the gas concentration in the large-diameter drill hole of the lagging working face are lower than the lower limit of the designed safety threshold, closing the large-diameter drill hole, stopping extracting the gas in the goaf from the large-diameter drill hole, restarting the large-diameter drill hole to extract the gas in the goaf after a certain time interval, keeping the large-diameter drill hole open when the extraction mixing amount and the gas concentration in the large-diameter drill hole are higher than the lower limit of the designed safety threshold, and closing the large-diameter drill hole when the extraction mixing amount and the gas concentration in the large-diameter drill hole are lower than the lower limit of the designed safety threshold.

Technical Field

The invention relates to a process for extracting gas from a goaf and an upper corner by drilling, in particular to a large-diameter drilling space-time coordination gas extraction method based on primary hole forming.

Background

The coal production environment is extremely severe, major disaster accidents occur frequently, gas disasters are one of the main forms of coal mine disasters in China, and the prevention and control of the upper corner gas concentration overrun is an important task of mine gas control. The existing technology for preventing and controlling the gas over-limit of the upper corner does not change the flow field of the goaf and the upper corner essentially, so that the treatment effect on the gas disaster of the goaf and the upper corner is not ideal. The existing large-diameter hole gas extraction process for the goaf can substantially change the gas flow field of the goaf and the upper corner, and prevent the problem that the gas at the upper corner exceeds the limit. However, the large-diameter drill hole is drilled in the protective coal pillar, the coal layer containing gas is soft and broken, and the hole forming method adopts the technology of repeatedly replacing drill bits with different sizes and repeatedly drilling, so that the construction time is long, the hole wall is damaged in the process of repeatedly drilling, the hole collapse phenomenon is easy to occur, the drilling and drilling failure is caused, and the design forming cannot be guaranteed; the failure of drilling large-diameter holes can damage the integrity of the protective coal pillars and cause instability of the coal pillars, the method of grouting the protective coal pillars is adopted at present, then the large-diameter holes are drilled, but the coal bodies are loose and broken, the grouting effect is poor, and the hole collapse phenomenon cannot be thoroughly solved; the processes of drilling and installing the large-diameter drill hole and installing the protective pipe are complex, the construction cost is increased due to too many drilling quantities, and the extraction effect of the large-diameter drill hole is not ideal due to too few drilling quantities. Therefore, under the background of solving the problems, a method for extracting gas in a space-time coordination manner in a large-diameter drill hole based on one-time hole forming is urgently needed, wherein the gas overrun of the upper corner can be effectively prevented and controlled.

Disclosure of Invention

In order to achieve the above purpose, the invention provides the following technical scheme:

the large-diameter borehole space-time coordination gas extraction method based on primary pore-forming comprises the following steps:

the method comprises the following steps: drilling a large-diameter drill hole from a measure roadway adjacent to the working surface on the side of the return airway to the return airway, wherein the large-diameter drill hole penetrates through the protective coal pillar; completing one-time hole forming operation by using a multi-stage combined drill bit, a large-diameter spiral drill rod and a drilling machine;

step two: pushing the high-strength negative-pressure large-diameter protective pipe into the large-diameter drill hole from the measure roadway by using a drilling machine to complete the installation operation of the protective pipe;

step three: sealing the large-diameter drill hole, wherein the sealing length of the two ends is more than one third of the total length of the large-diameter drill hole; after hole sealing is completed, mounting a double-eccentric butterfly valve and a gas drainage multi-parameter sensor at the exposed end of the high-strength negative-pressure large-diameter protective pipe at one end of the measure roadway, and connecting the double-eccentric butterfly valve and the gas drainage multi-parameter sensor into a gas extraction pipeline;

step four: in the return airway, connecting high-strength negative-pressure large-diameter protective pipes in large-diameter drill holes of the leading working face with a negative-pressure air duct respectively, suspending the negative-pressure air duct on the airway wall, extending the negative-pressure air duct to the upper corner position, and continuously extracting gas at the upper corner; directly extracting gas in the goaf by the large-diameter drill hole of the lagging working face to form a space extraction pipeline; and monitoring gas extraction data in a single large-diameter drill hole in real time, wherein the gas extraction data comprises extraction mixing amount and gas concentration, monitoring the gas concentration of an upper corner in real time, and adjusting the extraction time of the large-diameter drill hole in real time according to the monitoring data to form a large-diameter drill hole time-space coordinated extraction system.

The multi-stage combined drill bit in the first step comprises a guide drill bit, a guide drill rod and a multi-stage hole expanding drill bit, wherein the multi-stage hole expanding drill bit comprises at least two hole expanding drill bits with different diameters, including a first-stage hole expanding drill bit and a second-stage hole expanding drill bit; the one-time pore-forming drilling method for large-diameter drilling in the first step comprises the following steps: firstly, a guide drill bit, a guide drill rod, a multi-stage hole expanding drill bit and a large-diameter spiral drill rod are connected in sequence, a large-diameter drill hole is drilled from a measure roadway to a return airway in cooperation with a drilling machine, and when the guide drill bit is completely exposed in the return airway, drilling is stopped; detaching the guide drill bit in the return airway, continuing drilling, and stopping drilling when the primary reamer bit is completely exposed in the return airway; and repeating the operation until all the reaming bits are completely disassembled, and finally, completing the operation of withdrawing the drilling rod in the measure roadway.

In the fourth step, when the gas concentration of the upper corner exceeds the upper limit of the designed safety threshold, the extraction quantity and the extraction negative pressure of the large-diameter drill holes of the leading working face are increased, and the extraction negative pressures of a plurality of large-diameter drill holes which are the lagging working face and are closest to the working face are increased; when the gas concentration of the upper corner is lower than the lower limit of the designed safety threshold, reducing the extraction quantity of the large-diameter drill holes of the advanced working face or reducing the extraction negative pressure or reducing the extraction quantity of the large-diameter drill holes of the advanced working face and reducing the extraction negative pressure; when the extraction mixing amount and the gas concentration in the large-diameter drill hole of the lagging working face exceed the upper limit of a designed safety threshold, starting a plurality of large-diameter drill holes near the large-diameter drill hole to extract gas in the goaf, and increasing the extraction negative pressure of the large-diameter drill hole and the plurality of large-diameter drill holes near the large-diameter drill hole; when the extraction mixing amount and the gas concentration in the large-diameter drill hole of the lagging working face are lower than the lower limit of the designed safety threshold, closing the large-diameter drill hole, stopping extracting the gas in the goaf from the large-diameter drill hole, restarting the large-diameter drill hole to extract the gas in the goaf after a certain time interval, keeping the large-diameter drill hole open when the extraction mixing amount and the gas concentration in the large-diameter drill hole are higher than the lower limit of the designed safety threshold, and closing the large-diameter drill hole when the extraction mixing amount and the gas concentration in the large-diameter drill hole are lower than the lower limit of the designed safety threshold.

The invention has the beneficial effects that:

the method for forming the hole by the multistage combined drill bit at one time is adopted, so that the construction time is saved, the hole wall damage caused by repeated drilling is avoided, the hole collapse phenomenon can be effectively reduced, and the drilling efficiency and the success rate are greatly improved; the primary guide drill bit is connected with the guide drill rod, so that a good guide effect can be achieved, and the accuracy of drilling is ensured.

2, connecting a high-strength negative-pressure large-diameter protective pipe ahead of a working face in the return airway with a negative-pressure air duct to align to the position of an upper corner, so as to realize accurate gas extraction of the upper corner; and the large-diameter drill hole of the lagging working face extracts the gas in the goaf, so that the flow field of the goaf is fundamentally changed, and the gas is reduced to be gathered at the upper corner. Meanwhile, according to gas extraction data monitored in the upper corner and the high-strength negative-pressure large-diameter protective pipe, the extraction time of the large-diameter drill hole is dynamically adjusted in real time, and finally, the extraction system for extracting the gas in the goaf and the upper corner in a time-space coordinated manner in the large-diameter drill hole is formed.

Drawings

FIG. 1 is a schematic diagram of gas extraction from a large-diameter borehole according to an embodiment of the invention;

FIG. 2 is a schematic illustration of large diameter borehole drilling according to an embodiment of the present invention;

FIG. 3 is a schematic illustration of a multi-stage drill bit according to an embodiment of the present invention;

in FIGS. 1 to 3: 1-measure lane, 2-return air lane, 3-large-diameter drilling, 4-protective coal pillar, 5-negative pressure air duct, 6-upper corner, 7-guide working face, 8-goaf, 9-guide drill bit, 10-guide drill rod, 11-first-stage hole expanding drill bit, 12-second-stage hole expanding drill bit, 13-large-diameter spiral drill rod and 14-drilling machine.

Detailed Description

Following the above technical solutions, the technical solutions in the embodiments of the present invention will be clearly and completely described, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments available to those of ordinary skill in the art are within the scope of the present invention. The present invention will be described in further detail with reference to examples.

As shown in FIGS. 1 to 3, the invention provides a primary pore-forming based large-diameter borehole space-time coordination gas extraction method, which specifically comprises the following steps:

the method comprises the following steps: a measure lane 1 adjacent to a working face on the side of a return airway 2 is provided with a large-diameter drill hole to the return airway 2, a ZDY-6500LP drill 14 is arranged in the measure lane 1, a large-diameter drill hole 3 is arranged to the return airway 2, and the large-diameter drill hole 3 penetrates through a protective coal pillar 4. A pilot drill bit 9 with the diameter of 120mm is used for connecting a pilot drill rod 10 with the diameter of 108mm, the length of the pilot drill rod 10 is 300mm, and a large-diameter drill hole 3 is drilled by matching with a large-diameter spiral drill rod 13 with the diameter of 240 mm. Starting to drill, namely drilling from the measure roadway 1 to the return air roadway 2, and stopping drilling when the guide drill rod 10 is exposed for 100 mm; connecting a first-stage hole expanding drill bit 11 with the diameter of 240mm with the guide drill rod 10, continuing drilling, and stopping drilling when the first-stage hole expanding drill bit 11 is exposed for 100 mm; and connecting the secondary reamer bit 12 with the diameter of 420mm with the primary reamer bit 11, and continuing drilling. Stopping drilling until the guide drill bit 9 penetrates through the protective coal pillar and the guide drill rod 10 is completely exposed in the return airway 2; detaching a guide drill bit 9 and a guide drill rod 10 in the return airway 2, continuing drilling, and stopping drilling when a first-stage reamer bit 11 is completely exposed in the return airway 2; the first-stage hole expanding drill bit 11 is detached in the return airway 2, drilling is continued, and when the second-stage hole expanding drill bit 12 is completely exposed in the return airway 2, the drilling is stopped; and (5) completing the operation of withdrawing the drill rod in the measure roadway 1, and finally disassembling the secondary reamer bit 12.

Step two: the high-strength negative-pressure large-diameter protective pipe with the diameter of 350mm and the wall thickness of 6mm is pushed into the large-diameter drill hole 3 from the measure roadway 1 to the return roadway 2 by using the ZDY-6500LP drilling machine 14, and the exposed end of the high-strength negative-pressure large-diameter protective pipe is wrapped by gauze.

Step three: injecting a polyurethane hole sealing agent into a gap between the large-diameter drill hole 3 and the high-strength negative-pressure large-diameter protective pipe to seal holes, wherein the hole sealing lengths of two ends of the large-diameter drill hole 3 are all larger than one third of the total length of the drill hole; after hole sealing is finished, in the measure lane 1, a QDX3-6 butterfly valve and a GD3 type mining gas drainage multi-parameter sensor are installed on the high-strength negative-pressure large-diameter protective pipe and are connected to a gas extraction pipeline.

Step four: leading two large-diameter drill holes 3 with the closest working face 7, respectively connecting negative pressure air ducts 5 with the diameter of 400mm at one end in a return air lane 2, hanging the two negative pressure air ducts 5 on a lane side, extending to the upper corner 6, continuously extracting gas at the upper corner 6, increasing the extraction negative pressure of the large-diameter drill hole 3 of the leading working face 7 when the concentration of the gas at the upper corner 6 exceeds the upper limit of a designed safety threshold, simultaneously increasing the extraction negative pressure of the two large-diameter drill holes 3 with the lagging working face and the closest working face, and removing the negative pressure air duct 5 connected with the large-diameter drill hole 3 when the working face 7 is about to push one large-diameter drill hole 3 for the next large-diameter drill hole 3 of the leading working face; when the large-diameter drill hole 3 lags behind the working face 7, gas in the worked out section 8 is extracted under negative pressure, when the extraction mixing amount and the gas concentration in the large-diameter drill hole 3 of the lagging working face exceed the upper limit of the designed safety threshold, two large-diameter drill holes 3 near the large-diameter drill hole 3 are opened to extract gas in the worked out section 8, the extraction negative pressure of the large-diameter drill hole 3 and the two large-diameter drill holes 3 near the large-diameter drill hole 3 is increased, when the extraction mixing amount and the gas concentration in the large-diameter drill hole of the lagging working face 7 are lower than the lower limit of the designed safety threshold, the large-diameter drill hole 3 is closed, the extraction of the gas in the worked out section 8 by the large-diameter drill hole 3 is stopped, after a certain time interval, the large-diameter drill hole 3 is opened again to extract gas in the worked out section 8, when the extraction mixing amount and the gas concentration in the large-diameter drill hole 3 are higher than the lower limit of the designed safety threshold, the large-diameter drill hole 3 is kept opened, and when the extraction mixing amount and the gas concentration in the large-diameter drill hole 3 are lower limit of the designed safety threshold, the large diameter bore 3 is closed. Finally, an extraction system for extracting the gas in the goaf 8 and the upper corner 6 in a time-space coordination manner by using the large-diameter drill hole 3 is formed.