Research on High-efficiency Gas Extraction Technology Using Ultra Large Diameter Boreholes in Soft Coal Seams
WANG Wei
Abstract：The drilling and gas extraction technology has been widely used in the prevention and control of coal mine gas disasters,but the effect is not ideal in soft and protruding coal seams with characteristics such as soft coal quality,poor permeability,high gas content,and high pressure.In order to improve the efficiency of gas extraction from soft coal seams and achieve rapid elimination of outburst coal seams.Construction and effect investigation of gas extraction boreholes were conducted in soft outburst coal seams using large-diameter drilling tools and processes.Taking the 3205 working face of Zhongxing Coal Industry in Fenxi as the background,25 experimental boreholes with a diameter of Φ 300 mm were constructed in the coal seam,and a total of 60 comparative boreholes with other diameters were constructed in three groups.Through on-site investigation of the extraction effect,the average cumulative extraction volume of a single hole in the large-diameter experimental borehole was about 22.33 times,8.68 times,and 4.40 times that of the other three comparative boreholes.The extraction effect in the coal seam was good,and it could efficiently solve the industry problem of low extraction rate in soft coal seams.
Keywords：soft coal seamlarge aperture drillingefficient extractionextraction parameters
Publication Date：2025-02-28
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 8-12,25 )