Results 151 - 160 of 270

• Geologic Factors Influencing the Gas Content of Coalbeds in Southwestern Pennsylvania
  1/1/1988 - Reports of Investigations
  A Bureau of Mines geologic study of Pennsylvanian and Permian coalbeds in southwestern Pennsylvania was undertaken to determine the effects of coalbed geology and petrology on in situ coalbed gas contents.
• Horizontal Trajectories of Rotary-Drilled Holes
  1/1/1988 - Reports of Investigations
  This Bureau of Mines report investigates the horizontal trajectory of boreholes drilled in coalbeds using the rotary drilling technique.
• Clay Veins: Their Occurrence, Characteristics, and Support
  1/1/1987 - Reports of Investigations
  The Bureau of Mines investigated the physical characteristics of and roof instability problems associated with clay veins. This was accomplished by observing and mapping clay veins in surface and underground mines. The occurrence and origins of clay vei...
• Effects of Stimulation Treatments on Coalbeds and Surrounding Strata: Evidence from Underground Observations
  1/1/1987 - Reports of Investigations
  Stimulated vertical boreholes are an effective means of removing gas from coalbeds in advance of mining. This Bureau of Mines report examines the coal mine roof damage potential of stimulation treatments. Twenty-two government-sponsored stimulation trea...
• Gas Content Determinations of Salt Samples Using Acoustic Responses
  1/1/1987 - Reports of Investigations
  The Bureau of Mines has developed a practical methodology for determining occluded gas contents of domal rock salt samples. The method, which is portable and fieldworthy, provides results in 5 min or less.
• Method Factors for Anemometer Measurement at Pipe Outlets
  1/1/1987 - Reports of Investigations
  Gob holes are routinely used by the mining industry to vent methane from gobs and to prevent it from entering the mine ventilation system. In some cases, flows from gob holes are measured by centering an anemometer on the end of a discharge pipe. These ...
• Protective Structures for Low-Coal Shuttle Car Operator
  1/1/1987 - Reports of Investigations
  Three possible limited-coverage design scenarios (roll bars, sliding canopies, and flip-top canopies) were designed, fabricated, and evaluated for low-coal shuttle cars. All three designs were determined to be feasible and desirable.
• Accurate Directional Borehole Drilling: A Case Study at Navajo Dam, New Mexico
  1/1/1987 - Reports of Investigations
  Describes a project conducted by the Bureau of Mines in which the accurate directional drilling of a borehole was demonstrated with the objective of intercepting a designated target.
• Methane Contents of Oil Shale From the Piceance Basin, CO
  1/1/1987 - Reports of Investigations
  The Bureau of Mines determined the gas contents of 135 oil shale samples obtained from approximately 630 ft of core drilling. Drilling was done within a projected mining zone of the Cathedral Bluffs Mine, located in the Piceance basin of western Colorad...
• Comparisons Between Cross-Measure Boreholes and Surface Gob Holes
  1/1/1986 - Reports of Investigations
  The Bureau of Mines conducted studies to compare the effectiveness of the cross-measure borehole system with that of surface gob holes on two successively mined retreating longwalls in the Lower Kittanning coalbed. Only the cross-measure system was in o...