巷帮“三带”分布与顺层钻孔封孔深度研究

Study on the distribution of"three zones"of roadway side and the sealing depth of borehole along the formation

为了提高玉溪煤矿顺层钻孔瓦斯抽采浓度及抽采效率,基于合理封孔深度的重要性,根据玉溪煤矿现场测定条件,采用测定瓦斯含量法研究巷道"三带"分布规律,确定巷道周围松动圈范围并得出顺层钻孔合理封孔深度范围。通过现场抽采效果验证,证明顺层瓦斯抽采钻孔合理封孔深度应该超过集中应力带应力峰值点,最后确定玉溪煤矿顺层钻孔合理封孔深度为12.5m,大幅度提高了瓦斯的抽采浓度,延长了抽放衰减周期,为煤层瓦斯长时间预抽提供了技术支撑,实现了矿井高浓度瓦斯的稳定利用,增加了安全保障,创造了经济效益。

Based on the importance of reasonable sealing depth,in order to improve the gas extraction concentration and efficiency of drilling along the seam in Yuxi coal mine,and according to the on-site measurement conditions of Yuxi coal mine,the gas content measurement method is used to study the distribution lawof“three zones”in the roadway,the loose circle around the roadway is determined and the reasonable sealing depth range of drilling along the seam is obtained.Through the verification of the field drainage effect,it is proved that the reasonable sealing depth of the borehole should exceed the peak point of the stress in the concentrated stress zone.At last,it is determined that the reasonable sealing depth of the borehole in Yuxi coal mine is 12.5 m,which greatly improves the drainage concentration of the gas,prolongs the drainage attenuation period,provides technical support for the long-term pre-drainage of the coal seam gas,and realizes the high concentration gas in the mine.The stable utilization of the technology has increased the security and created economic benefits.