奥陶系石灰岩含水层钻孔
boreholes in aquifer of Ordovician limestone
穿层钻孔
borehole through strata
through coal delaminations’bore
penetrating borehole
土层钻孔应力测量
Soil layer bore stress measure
大孔钻孔
big-diameter hole drilling
精密深孔钻孔工具
precision deep hole drilling tool