考虑煤层含水率的穿层钻孔布置参数优化研究

Study on Parameters Optimization of Layer-through Borehole Layout Considering Moisture Content of Coal Seam

针对于含水率较大煤层的瓦斯钻孔抽采半径受含水率影响较大的问题,借助含水率与煤体渗透率的动态关系,结合误差对比分析,对瓦斯压力值进行参数拟合,得出了适用于水-瓦斯-煤三相耦合的Klinkenberg效应方程及煤体孔隙率-含水率关系的方程。在上述模型基础下,结合现场实际条件,模拟了穿层钻孔最佳的抽采半径,并在现场运用,钻孔间距10 m时瓦斯抽出在73.2%左右,抽采效果良好。

For the problem that the gas drilling extraction radius of coal seam with large moisture content are greatly influenced by the moisture content, in this paper, by means of the dynamic relationship between moisture content and permeability of coal, combining with comparative analysis of the error and gas pressure value parameter fitting, the Klinkenberg effect equation which is suitable for water-gas-coal three phase coupling and the relationship equation between porosity and moisture content of coal body are obtained. Based on the above model, combined with the actual conditions, the best extraction radius of layer-through drilling is simulated; in the field application, the percent of gas extraction is about 73.2% when borehole spacing is 10 m, and the extraction effect is good.