基于灰关联分析的顺层钻孔瓦斯抽采有效半径主控因素研究

Research on main controlling factors of effective radius for gas extraction using hole drilled along seam based on grey relational analysis

基于顺层抽采钻孔固气耦合模型,采用COMSOL对钻孔直径、煤层物性参数及抽采参数三类因素进行了模拟分析,并运用灰关联分析方法确定了顺层钻孔瓦斯抽采有效半径的主控因素。研究表明:煤层初始瓦斯压力与煤体初始渗透率为有效半径的主控因素,抽采时间次之,钻孔直径与有效抽采负压的变化对有效半径的影响甚微;提高瓦斯抽采有效半径的首要任务是通过技术手段卸压、增透,其次要把握合理的预抽时间。

Based on solid-gas coupling model of gas extraction using hole drilled along seam, three types of factors such as borehole diameter, physical parameters of coal seam and gas extraction parameters were simulated and analyzed by using COMSOL, and the main controlling factors of effective radius for gas extraction using hole drilled along seam were obtained by using the method of grey relational analysis. It showed that the initial gas pressure in coal seam and initial permeability of coal body are the main controlling factors of effective radius, the gas extraction time takes second place, while the borehole diameter and effective negative pressure of extraction have a little effect on effective radius. Therefore, the primary task of improving effective radius for gas extraction is to decrease initialgas pressure and increase initial permeability of coal body, secondly it is necessary to control reasonable extraction time.