Results 341 - 348 of 348

• Bleeder System in Virgin Area in a Pittsburgh Coalbed Mine
  1/1/1973 - Reports of Investigations
  Air quantity-pressure and methane concentration surveys were conducted in accessible portions of an area being pillared in a Pittsburgh coalbed mine in West Virginia.
• Demonstration of Safety Plugging of Oil Wells Penetrating Appalachian Coal Mines
  7/1/1972 - Technical Progress Reports
  An 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 ...
• Effect of a Surface Borehole on Longwall Gob Degasification (Pocahontas No. 3 Coalbed)
  1/1/1972 - Reports of Investigations
  The use of a partially slotted 6.5-Inch-inside-diameter vertical pipe to remove methane from a longwall gob area at a depth of 2,260 feet in the Pocahontas No. 3 Coalbed was investigated. The value of gas removed by such a pipe under free-flow condition...
• Methane Emission in Coal Mines: Effects of Oil and Gas Wells
  1/1/1972 - Reports of Investigations
  The 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...
• Behavior of Coal-Gas Reservoirs
  5/1/1969 - Technical Progress Reports
  Gas 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 ...
• Use of Vertical Boreholes for Assisting Ventilation of Longwall Gob Areas
  3/1/1969 - Technical Progress Reports
  An experimental degasification program using a vertical borehole and vacuum pump to drain gas from the gob area of a longwall panel was successful at Bethlehem Mines Corporation, Cambria Division, No. 33 coal mine. Sixty-one million cubic feet of methan...
• Removing Methane (Degasification) from the Pocahontas No. 4 Coalbed in Southern West Virginia
  1/1/1963 - Reports of Investigations
  Tests were conducted in the Pocahontas No. 4 coalbed in southern West Virginia to determine if successful degasification techniques, developed during an earlier study in the Pittsburgh coalbed, would effectively remove methane from those usually more ga...
• Leakage and Performance Characteristics of Large Stoppings for Room-and-Pillar Mining
  1/1/1988 - Reports of Investigations
  This report presents a Bureau of Mines study comparing the construction costs, leakage measurements, and predicted performance of different types of large stoppings built and tested in a room-and- pillar oil shale mine.