利用分段压水试验成果对煤层顶部隔水层稳定性进行评价

Coal Roof Aquifuge Stability Assessment through Segmented Packer Permeability Test

内蒙古XX煤矿在开采3-1煤层时,因冒裂带发育较大,可能会导通第四系含水层。通过对以往钻探和测井资料分析发现,3-1煤层冒裂带顶部存在一较连续稳定的隔水层段。利用压水试验原理,在矿井的两个水文钻孔中对该隔水层段进行了分段压水试验。试验结果表明:在常规压力下,S5-2和S10-1孔测试段岩体均为微-弱透水岩体,在高压下,S5-2三个测试段,均位于泥岩-砂质泥岩段,总体上测试结果为弱透水岩体,S10-1共进行了5个位置的压水试验,其中三个表现为弱透水层,距细砂岩层较近的第三、第四测段,则表现为弱-中透水岩体。室内岩心测试结果与压水试验所得结论基本一致。该研究为煤矿防治水工作提供了科学依据,对查明矿区开采技术条件具有重要的意义。

During the mining of coal No.3-1 in an Inner Mongolian coalmine, since the wide range of caving zone, probably may con-duct the Quaternary aquifer. Through the analysis of past drilling and well logging data has shown that a continuous and stable aquifuge existed on the top of coal No.3-1 caving zone. Thus segmented packer permeability test carried out for the aquifuge in two hydrogeologi-cal boreholes. The result has shown that under the normal pressure, rock mass in boreholes S5-2 and S10-1 tested segments is all min-ute to weak permeable rock mass;under the high pressure, the three tested segments in S5-2 are all mudstone-sandy mudstone weak permeable rock mass, five tested segments in S10-1, three of them are weak permeable rock mass, the Nos.3 and 4 tested segments near fine-grained sandstone are weak-medium permeable rock mass. The conclusions from laboratory rock core tests and packer per-meability tests are basically the same. The study has provided scientific basis for coalmine water control works and great significance in mining technical condition verification.