Results 121 - 130 of 149

• Methane Emissions from Four Working Places in the Beckley Mine, Raleigh County, W. Va.
  1/1/1977 - Reports of Investigations
  The Beckley Mine is one of five new mines in a heretofore unmined portion of the Beckley coalbed. The remoteness of these new mines from prior mining and their greater overburden preclude applying methane emission experience obtained in the old mines. F...
• Hydraulic Stimulation of a Surface Borehole for Gob Degasification
  1/1/1977 - Reports of Investigations
  The Bureau of Mines evaluated the hydraulic stimulation of a gob degasification borehole to determine if this procedure would aid in degasifying a longwall panel.
• Methane Gas Content of the Mary Lee Group of Coalbeds, Jefferson, Tuscaloosa, and Walker Counties, Ala.
  1/1/1976 - Reports of Investigations
  It is estimated that more than 1 trillion cubic feet of methane is contained within the coals of the Mary Lee Group in Jefferson, eastern Tuscaloosa, and southern Walker Counties, Alabama. It is calculated that approximately 90 pct of the methane is at ...
• Methane Emissions from an Advancing Coal Mine Section in the Pittsburgh Coalbed
  1/1/1976 - Reports of Investigations
  The methane emissions from an advancing coal mine section were continuously monitored for 120 days. During this time, the section advanced 2,000 feet into virgin Pittsburgh coalbed producing 54,565 tons of coal with a total methane emission of 91 millio...
• Geological Factors Affecting Methane in the Beckley Coalbed
  1/1/1976 - Reports of Investigations
  This Bureau of Mines study reviews the geological factors that affect methane in the Beckley coalbed in southern West Virginia, including overburden, coalbed structure, type and changes in lithology above and below the Beckley coalbed.
• Longwall Gob Degasification With Surface Ventilation Boreholes Above the Lower Kittanning Coalbed
  1/1/1976 - Reports of Investigations
  Methane emission from two surface gob-degasification boreholes was measured by the Bureau of Mines. The investigation took place during mining of a 3,200-foot longwall panel in the Lower Kittanning coalbed in central Pennsylvania. The first hole was 500...
• Measuring the Methane Content of Bituminous Coalbeds
  1/1/1975 - Reports of Investigations
  The methane content of virgin bituminous coalbed can now be measured accurately in the field with exploration core samples from vertical boreholes. The gas content of the coal per unit weight can be used either to design a mine ventilation system or to ...
• Two-Phase Flow in Coalbeds
  1/1/1975 - Reports of Investigations
  This report reviews experimental evidence indicating a relative permeability effect that causes the flow of methane to increase with time when a coalbed is degassed by boreholes.
• Research on the Transmission of Electromagnetic Signals Between Mine Workings and the Surface
  1/10/1974 - Contract reports
  Field studies of ambient electromagnetic noise and electrical transmission properties of coal mine overburdens in Colorado, Illinois, Pennsylvania, and West Virginia were conducted. Field tests of the transmission of low-frequency (20 hz to 20,000 hz) s...
• Peak Methane Concentrations During Coal Mining: An Analysis
  1/1/1974 - Reports of Investigations
  Methane concentration peaks were measured at coal mine working faces during entry development. The statistical distribution of peaks was found to be normal or log normal depending on how well the methane was being mixed into the ventilation airstream.