摘要
为提高顺层钻孔抽采瓦斯的效率,以大佛寺40204工作面顺层钻孔抽采工程为背景,开展了瓦斯抽采钻孔参数优化研究。通过数值方法,建立了基于煤体塑性变形的流固耦合瓦斯抽采模型,研究了钻孔孔径、钻孔间距对煤层瓦斯抽采的影响,优化了钻孔布置。结果表明,增大钻孔孔径将使煤岩塑性破坏加重,孔径φ153 mm钻孔的塑性破坏区面积为φ93 mm钻孔塑性破坏区的3.7倍,其有助于煤岩渗透率的增加,加快抽采煤层瓦斯压力的降低;减小钻孔间距有助于塑性破坏区域的扩展,随钻孔数量增加,间距1.5 m的塑性破坏区面积是间距3 m时的4.2倍,缩短间距可使相邻钻孔间煤岩渗透率整体提升,有助于瓦斯抽采。通过优化孔径及孔间距,以抽采后煤层残余瓦斯压力为指标,确定适合该矿的合理钻孔布置方案为孔径φ113 mm,钻孔间距2 m。
To improve the efficiency of gas drainage through drilling borehole, the optimization of drilling parameters for gas drainage was carried out on the background of boreholes of Dafosi 40204mining seam. By numerical method, a fluid-solid coupling gas drainage model based on the plastic deformation of coal body was established, the influence of borehole diameter and borehole spacing distance on coal seam gas drainage was studied. And, the drilling arrangement is optimized. Results show that increasing the borehole diameter will increase the plastic damage of coal rock, and the area of the plastic damage zone of the φ153 mm borehole is about 3.7 times that of the φ93 mm borehole.That is useful for the gas drainage and decreasing of coal seam gas pressures. Reducing the spacing distance of drill holes helps to expand the plastic failure area. With the increase of the number of boreholes, the area of the plastic failure area with a spacing of 1.5 m is about 4.2 times that of the spacing of 3 m. The overall increase in the permeability of coal and rock between adjacent boreholes is helpful for the gas drainages. With previous results, the borehole diameter and drilling spacing distance are optimized. Considering the residual gas pressure of the coal seams as an index, the reasonable drilling parameters for the mine are determined as the borehole diameter of φ113 mm and drilling spacing distance of 2 m.
作者
窦成义
李庆钊
马旭
DOU Chengyi;LI Qingzhao;MA Xu(Shaanxi Binchang Dafosi Mining Co.,Ltd.,Xianyang 712000,China;School of Safety Engineering,China University of Mining and Technology,Xuzhou 221116,China)
出处
《煤炭技术》
CAS
北大核心
2023年第3期167-172,共6页
Coal Technology
基金
国家自然科学基金面上项目(51974303)。
关键词
瓦斯抽采
塑性破坏
钻孔参数
瓦斯压力
渗透率
gas drainage
plastic failure
drilling parameters
gas pressure
permeability
