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Results 81 - 89 of 89
1/1/1980 - Reports of InvestigationsThe face ventilation measurement method developed by the Bureau of Mines involves releasing a small volume of tracer gas (SF6) on the off-curtain side of the working face at the start of the mining cycle.
1/1/1978 - Reports of InvestigationsIn this Bureau of Mines investigation, production was monitored for 1 year at over 30 coalbed gas-drainage boreholes located in Alabama, Pennsylvania, and West Virginia.
1/1/1977 - Reports of InvestigationsTwo degasification test boreholes were drilled to depths of 1,238 and 1,212 feet on Bureau of Mines property at Bruceton, Pennsylvania, as part of the Bureau of Mines long-range coal degasification program.
1/1/1976 - Reports of InvestigationsThis report describes three coal mine ventilation studies by the Bureau of Mines in which sulfur hexafluoride (SF6) was used as a tracer gas.
1/1/1975 - Reports of InvestigationsThis report describes a multipurpose borehole used for both degasification and the production of commercial-quality gas. The multipurpose borehole was drilled into a barrier pillar, and seven horizontal degasification holes and one pressure point hole w...
1/1/1974 - Reports of InvestigationsThe Bureau of Mines has successfully used sulfur hexafluoride (SF6) as a tracer gas to measure mine air flows under conditions where conventional methods have failed. SF6 was employed experimentally to measure accurately recirculation of return into int...
1/1/1974 - Reports of InvestigationsThe Bureau of Mines found sulfur hexafluoride (SF6), released from a lecture bottle, to be an ideal gaseous tracer for studying mine ventilation systems. In a Pennsylvania limestone mine, this technique was useful in evaluating the effectiveness of auxi...
1/1/1973 - Reports of InvestigationsSamples of gas were obtained directly from the coalbed during drilling of horizontal and vertical boreholes in six different formations. The samples were analyzed by gas chromatography.
7/1/1972 - Technical Progress ReportsAn oil well penetrating the Pittsburgh bituminous coalbed in northern West Virginia was plugged and safely mined through 3 months later. Effectiveness of the plugging in preventing reservoir gas from entering the mine through the well hole was verified ...