不同性质外液对煤与瓦斯突出防治效果影响

Different kinds of external solution impact on prevention and cure effect of coal and gas outburst

针对煤层注水防止工作面煤与瓦斯突出问题,以七台河新兴煤矿92#煤层工作面生产条件为背景,采用数值模拟研究和现场工业试验相结合的方法,研究了注入介质为纯水和表面活性剂溶液时,其对工作面钻孔围岩塑性浸润区和工作面垂直应力分布规律的影响。结果表明:具有煤与瓦斯突出危险的回采工作面预采煤体注液后,能够降低应力峰值、增加峰值距、扩大应力增高区的覆盖范围,从而使防突效果提高;防突效果的提高程度与所注入的外液性质有关,表现为表面活性剂溶液强于纯水;钻孔注液后,孔间塑性浸润区的发展状态与注液压力及所注入的流体介质性质有关。相同流体介质条件下,注液压力越大,塑性浸润区的发育范围也越大;在纯水中加入表面活性剂之后,其孔间塑性浸润区的发育不仅范围更大,速度更快,且在各方向上更为均匀。该研究对注水防止煤与瓦斯突出具有很好的实际指导意义。

Aimed at addressing the problem resulting trom injecting water into coal seam to prevent coal and gas outburst, this paper builds on coal face production condition of Qitaihe Xinxing colliery 92^# coal seam and describes the use of the combined method of numerical simulation research and the indus- trial test to study the impact of pure water and surfactant solution on plastic infiltration area around drill hole and vertical stress distribution of coal face. The results show that injecting external solution into the preliminary coal body vulnerable to coal and gas outburst danger contributes to reducing stress peak, in- creasing stress peak distance, expanding overage of stress increase area, and thus improving the outburst prevention effect. The outburst prevention effect depends on external solution properties in such a way that surfactant solution is better than pure water. Solution injection into drill hole leads to the correlation between the development state of plastic infiltration range on the one hand and drill holes, injection pres- sure, and fluid medium properties on the other hand. With the same fluid medium condition, a higher injection pressure results in a wider the plastic infiltration area range around drill hole; adding surfaetant into pure water allows plastic infiltration area between drill holes to develop not only at a greater range and higher speed faster, but also with a better uniformity in each direction. The study is of significance to oreventing coal and gas outburst by using water iniection.