基于FLAC数值模拟的突出煤层钻冲设计优化

Design Optimization of Drilling and Hydraulic Flushing in Outburst Coal Seam Based on FLAC Numerical Simulation

采用穿层钻孔钻冲耦合抽采模式,实现普通钻孔和钻冲一体化钻孔的耦合分布,使得区域瓦斯治理由穿层钻孔的个体分散式抽采转变为区域煤体的整体卸压式抽采。通过不同种类抽采钻孔的耦合分布,有效破解了单个钻孔形成的局部应力集中;有效减少了高瓦斯突出煤层中穿层钻孔的喷孔、堵孔现象,增大了单孔影响范围,实现了区域煤体的整体卸压增透,减少了预抽钻孔数量和长度,提高了煤层瓦斯预抽率。

By using the gas drainage model combined with layer-through boreholes and hydraulic flushing,the coupling distribution of normal boreholes and integration boreholes（ using for gas drainage and hydraulic flushing） were obtained,the regional gas control was changed from the extraction of individual distributed drilling into the whole coal pressure releasing extraction. Through the coupling distribution of different extraction boreholes,local stress concentration formed by single borehole was effectively cracked,orifice and blocking phenomena of layer-through boreholes were also reduced effectively,moreover,the influencing scope of single boreholes was enlarged,the whole coal pressure releasing extraction was realized,too. The number and length of pre-drainage boreholes was reduced,gas pre-drainage ratio of coal seam was improved,too.