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Results 51 - 56 of 56
1/1/1972 - Reports of InvestigationsThe method of moving averages was found useful in assessing the nature of methane emission in coal mines. Emission rates were influenced markedly by the presence of abandoned oil and gas wells in the vicinity of the mine. Such wells appeared to increase...
The Methane Migration and Storage Characteristics of the Pittsburgh, Pocahontas No. 3, and Oklahoma Hartshorne Coalbeds1/1/1972 - Reports of InvestigationsMethane flows and pressures were measured in mines in the Pittsburgh, Hartshorne, and Pocahontas No. 3 Coalbeds. From the data, the permeability of each of these coalbeds was computed.
1/1/1971 - Reports of InvestigationsThe purpose of this study was to determine the characteristics of methane emissions during coal extraction by a longwall mining system. The study was conducted over 22 consecutive shifts. The average methane emission rate from the Lower Kittanning coalb...
8/1/1970 - Technical Progress ReportsMethane emission rates were studied in a Pittsburgh coalbed mine in northern West Virginia. Air volumes and methane percentages were recorded, and time studies of the miner were made during five consecutive operating days, during which a complete cycle...
5/1/1969 - Technical Progress ReportsGas occurs in coalbeds in an adsorbed and a free gas state. Adsorbed gas is stored in the micropore structure and its transport is governed by Fick's law. The free gas occurs in the fracture system and flows according to Darcy's law. These two modes of ...
1/1/1962 - Reports of InvestigationsA joint investigation by the Bureau of Mines and the Christopher Coal Co. at the Humphrey No. 7 mine, operating in the Pittsburgh coalbed in northern West Virginia, was undertaken to gain more insight concerning the hazardous emission of methane gas in ...