发明名称 Method for determining mine roof competency
摘要 Mine roof competency is determined by injecting a pressurized gas into a borehole drilled in the roof of the mine and measuring the rate of pressure loss. A high rate of pressure loss is indicative of a dangerous mine roof. A tracer gas may also be injected into the borehole to determine the extent of cracks in the roof if a dangerous condition has been determined.
申请公布号 US4686849(A) 申请公布日期 1987.08.18
申请号 US19850805772 申请日期 1985.12.06
申请人 CZIRR, JOHN B. 发明人 CZIRR, JOHN B.
分类号 E21B47/10;E21B49/00;E21F17/18;(IPC1-7):G01N15/08;G01N19/08 主分类号 E21B47/10
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