顺层定向千米长钻孔抽采半径时变规律研究

Research on Time Varying Laws of Extraction Radius for Bedding Directional 1 000 m Long Drilling

根据某矿3~#煤层赋存特点,运用千米钻机定向长钻孔技术进行本煤层瓦斯预抽。通过千米钻孔现场数据对其瓦斯抽采特性进行统计分析,得到钻孔抽采瓦斯量的衰减特征参数,结合煤层瓦斯基本参数得出3~#煤层千米钻孔抽采半径时变规律;同时对不同钻孔间距的瓦斯流场进行分析,数值模拟得出合理布孔间距,经现场验证证实抽采准确率可达80%,该方法可作为3~#煤层预抽钻孔防突效果预测。

According to the occurrence characteristics of 3^# coal seam in a mine,1 000 m drilling machine with directional long drilling technology is used for the coal seam gas drainage.The field data of gas extracting from 1 000 m drill hole were put into statistical analysis,and the attenuation parameters of gas extraction were obtained.Combined with the basic parameters of 3^# coal seam,the gas extraction radius variation can be found.Reasonable hole spacing can be concluded by analyzing and numerically simulating gas flow field among different drilling holes.Spot verification proves that the accuracy rate of extraction can reach 80%.Thus,this method is helpful to predict the effect of outburst prevention.