Results 71 - 80 of 126

• Degasification of the Mary Lee Coalbed, Brookwood, Ala
  1/1/1982 - Reports of Investigations
  The Bureau of Mines has developed several techniques for draining methane from coalbeds in advance of mining. Drilling long horizontal holes from an underground location is one such technique, which was successfully demonstrated in the Pittsburgh and Su...
• Probability of Encountering Coalbed Discontinuities During Vertical and Horizontal Borehole Drilling
  1/1/1982 - Reports of Investigations
  Probabilities of encountering coalbed discontinuities during vertical or horizontal drilling in a specific coalbed can be estimated based on analysis of mined-out areas of the coalbed where the size, shape, orientation, and distribution of discontinuiti...
• Assessing the Methane Hazard of Gassy Coals in Storage Silos
  1/1/1981 - Reports of Investigations
  The Bureau of Mines investigated coal storage silos to determine how gassy coal must be for methane accumulations in a silo to become hazardous and where such accumulations are likely to occur. Methane concentrations were measured in the open space abov...
• Methane Drainage Study Using an Underground Pipeline, Marianna Mine 58
  1/1/1981 - Reports of Investigations
  The Bureau of Mines has completed an underground degasification project in which an underground piping system was used to transport methane from the coalbed to the surface. In a 10-month period four horizontal holes were drilled to an average depth of 1...
• Direct Method Determination of the Gas Content of Coal: Procedures and Results
  1/1/1981 - Reports of Investigations
  Describes a simple, inexpensive test to measure the methane content of coal samples obtained from exploration cores. The results of tests are summarized in tabular form. These results include data on the gas content of 125 coalbeds in 15 states.
• Face Ventilation Measurement with Sulfur Hexafluoride (SF6)
  1/1/1980 - Reports of Investigations
  The 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.
• A Fail-Safe Control System for a Mine Methane Pipeline
  1/1/1980 - Reports of Investigations
  The Bureau of Mines has designed and put into operation a fail-safe control system for use in underground coal mines equipped with methane drainage pipelines. This control system can detect certain unsafe conditions and respond by automatically shutting...
• Three Coal Mine Gob Degasification Studies Using Surface Boreholes and a Bleeder System
  1/1/1980 - Reports of Investigations
  The use of vertical surface degasification boreholes with bleeder systems and the use of a timbered bleeder system to degasify gob areas were studied by the Bureau of Mines. This report describes three gob degasification studies conducted in the Pittsbu...
• Drainage of Methane From the Overlying Pocahontas No. 4 Coalbed From Workings in the Pocahontas No. 3 Coalbed
  1/1/1979 - Reports of Investigations
  The Bureau of Mines conducted an experimental degasification project in Island Creek Coal Company Virginia Pocahontas No. 5 Mine. Methane from the overlying Pocahontas No. 4 Coalbed was entering mine workings in the Pocahontas No. 3 Coalbed through frac...
• Methane Content and Geology of the Hartshorne Coalbed in Haskell and Le Flore Counties, Okla.
  1/1/1979 - Reports of Investigations
  The Bureau of Mines developed data on the methane content of the Hartshorne coalbed, Haskell and Le Flore Counties, Oklahoma. The methane content is calculated to be between 1.1 and 1.5 trillion cubic feet. Methane increases with depth, but the rate of ...