Results 221 - 230 of 270

• Geology and Gas Content of Coalbeds in Vicinity of Bureau of Mines, Bruceton, Pa.
  1/1/1977 - Reports of Investigations
  Two 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.
• Three Coal Mine Ventilation Studies Using Sulfur Hexafluoride Tracer Gas
  1/1/1976 - Reports of Investigations
  This report describes three coal mine ventilation studies by the Bureau of Mines in which sulfur hexafluoride (SF6) was used as a tracer gas.
• Degasification and Production of Natural Gas From an Air Shaft in the Pittsburgh Coalbed
  1/1/1976 - Reports of Investigations
  The Bureau of Mines conducted research to determine the effectiveness of long holes drilled in solid virgin coal in degasifying an area of the Pittsburgh coalbed showing that horizontal holes drilled into a virgin coalbed from the bottom of any shaft wi...
• 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 ...
• Use of Surface Joint and Photolinear Data for Predicting Subsurface Coal Cleat Orientation
  1/1/1976 - Reports of Investigations
  Coalbeds exhibit a directional permeability, with the maximum permeability oriented parallel to the face cleat. Thus, the most efficient pattern of vertical degasification holes for a coalbed is dependent upon cleat orientation. Analysis of surface joi...
• An Electromagnetic System for Detecting and Locating Trapped Miners
  1/1/1976 - Reports of Investigations
  The theory of electromagnetic fields indicates such fields could be used to detect and locate trapped miners. To be useful, the hardware of the system must meet a number of requirements, including small size, intrinsic safety, and rugged construction. S...
• 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...
• Seismic Detection of Trapped Miners Using In-Mine Geophones
  1/1/1976 - Reports of Investigations
  A seismic system which utilizes in-mine geophones to detect trapped miners has been developed. Tests at the Bureau of Mines safety research mine at Bruceton, Pennsylvania, and at two operating mines indicate such a system has a maximum detection range i...
• 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.
• Determining Cleat Orientation of Deeper Coalbeds From Overlying Coals
  1/1/1976 - Reports of Investigations
  Examination of several coalbeds in Walker County, Alabama, Cambria, Greene, and Fayette Counties, Pennsylvania, and Caleigh and Wyoming Counties, West Virginia, indicates that cleat orientations are similar throughout a vertical sequence of strata. Stud...