巴拉素井田煤层富水机理与注浆堵水技术

陕北侏罗纪煤田榆横矿区(北区)是我国重要的煤炭生产基地,区内大型矿井分布较多,煤层埋藏相对较深,在采掘过程中发现有富水煤层问题。为研究区内煤层富水机理及采掘过程中的水害问题,以巴拉素煤矿2号富水煤层注浆堵水治理工程为例,通过对水文地质条件和地下含水层之间水力联系情况分析,查明了区内各含水层水文地质特征及类型,确定了2号煤层水为立井井筒过煤层段的主要充水水源,并提出了富水煤层注浆治理保障新技术。通过抽水试验、水化学测试,发现区内地下水含水层主要为第四系松散层潜水含水层、白垩系下统洛河组孔隙-裂隙含水层、侏罗系中统直罗组碎屑岩类裂隙含水层、2号煤顶板延安组碎屑岩类裂隙含水层、2号煤层含水层等。第四系松散潜水含水层和白垩系洛河组孔隙裂隙含水层之间水力联系密切,其他含水层之间均未发现水力联系。根据现场实际及多次实践,确定以"引流注浆、帷幕封堵"为总体思路,运用"井下打钻,地面拌浆,管道输送,高压灌注"的方法,完成2号煤层富水区段的封堵。研究及实践结果表明:通过多种材料结合、钻探注浆等组合工艺实施后,在副立井井筒马头门煤层揭露区段及待掘巷道周围形成了有效的止水帷幕,将掘进巷道与富水煤层隔开,最大程度地减小井筒涌水量,超出预期目标完成注浆堵水任务,副立井井筒总涌水量由最初的150 m~3/h(最高200 m~3/h)衰减至竣工时的11 m~3/h,注浆堵水率约为93%,实现了对富水煤层大量出水有效封堵的目的。

Water rich mechanism of coal seam and grouting and blocking water technology in Balasu mine feild

With plenty of large mines and relatively deep buried coal seam,Yuheng mining area (north area) of Jurassic coalfield in northern Shaanxi Province is an important coal production base in China.However,the water rich coal seam also brings a lot of issues in the mining process,which are very rare both in China and the world.To study the water rich mechanism of coal seam and the water hazards in the mining process,this paper takes the grouting and blocking water project of No.2 water rich coal seam of Balasu coal mine as an example.Based on the analysis of the hydrogeological conditions and the hydraulic relationship between the underground aquifers,this study ascertained the hydrogeological characteristics and types of each aquifer in the region,identified that No.2 coal seam water was the main water source for the vertical shaft passing through the coal seam,then put forward a new security technology for water rich coal seam grouting treatment for the first time.Through pumping test and hydrochemical test,it was found that the groundwater aquifers in the area mainly contain the Quaternary loose phreatic aquifer,the pore fissure aquifer of lower Cretaceous Luohe formation,the clastic rock fissure aquifer of middle Jurassic Zhiluo formation,the clastic rock fissure aquifer of No.2 coal seam roof Yan’an formation,and the No.2 coal seam aquifer,etc.A close hydraulic relationship between the Quaternary loose phreatic aquifer and the Cretaceous Luohe formation pore fissure aquifer was found,but no hydraulic relationship was found among other aquifers.After trying for many times,the sealing of No.2 water rich coal seam was successfully completed with the general idea of “drainage grouting,curtain sealing” and the methods of “drilling underground,slurry mixing on the ground,pipeline transportation and high pressure perfusion”.The research shows that an effective water stopping curtain can be formed around the exposed section of shaft inset coal seam and the roadway to be excavated in the auxiliary shaft through the combination of various materials and the implementation of drilling grouting technique.As a result,the drivage roadway and water rich coal seam was separated,the shaft water inflow was minimized,the grouting and blocking water task was finished beyond expectation the auxiliary shaft lining total water inflow decreased from the original 150 m3/h (maximum 200 m3/h) to 11 m3/h when completed,the grouting and blocking water rate reaching to 93%.Moreover,the results show that sealing the large amount of effluent from water rich coal seam was realized with a good engineering effect,proving the remarkable achievements of water prevention and control security technology.