Abstract
This research aims to obtain a new way based on the directional long borehole layout to investigate the gas migration behavior of coal bed methane. In view of the study of the oil‐type gas reservoir and the influence range of mining on the working face in the surrounding rock, the paper puts forward the optimization method of the directional long borehole layout of the surrounding rock and the method of the borehole layout with comprehensive consideration of the influence of mining on the failure of the roof and floor and the distribution of surrounding rock gas‐bearing reservoirs. The test results showed that the layout horizon of the directional long boreholes is determined, and the layout was within the height range of 20–40 meters, clarified the relationship between the drainage data and the exposure level of the borehole and the layout of the borehole, compared the gas concentration in the upper corner of the working face before and after the drainage, and constructed a three‐dimensional comprehensive drainage mode for the high‐gassy working face, which provided a worth‐promoting method that supports surrounding rock oil‐type gas and gas treatment in the high‐gas mining area.
Highlights
China is one of the countries with the most serious coal mine gas problem in the world, and gas disaster is the biggest threat to coal mine safety production
It has been proved that gas extraction is the fundamental measure to prevent and control coal mine gas disasters and accidents
In order to achieve multidimensional full coverage in space, it is proposed to carry out three-dimensional comprehensive gas extraction in space by implementing directional long drilling holes in the roof and floor and, at the same time, to achieve “premining, in-mining, and postmining” gas exploration and extraction mode in terms of time
Summary
China is one of the countries with the most serious coal mine gas problem in the world, and gas disaster is the biggest threat to coal mine safety production. E key problem is to control the borehole trajectory accurately, which is the directional drilling technology of the surrounding rock. Wang et al [1] and Jiang et al [2] researched the influence of the long borehole when it comes to coal and coal-bed methane extraction based on the example of coal mines in China’s mining area. With the increase mining depth of coal mines in China, the quantity of outburst mines and outburst coal seams keeps increasing; Cheng and Yu [3,4] expatiated the necessity of controlling gas in the long drilling hole. To further improve the application of directional long drilling construction technology in the coal seam surrounding rock, efficient preextraction of coal seam gas and surrounding rock oil-type gas can effectively prevent the problem of gas concentration exceeding the limit in the upper corner of goaf. The prepumping drilling can be used for both geological exploration and “one hole for multiple purposes.” e layer of the directional long hole in the surrounding rock was selected and the implementation effect of the directional long hole was tested, so as to provide practical reference for replacing the roadway with holes and provide the development direction for the technical breakthrough of traditional roof highposition hole technology
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
