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- Mine locations, excavations, and structures:
- Boreholes
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- Reports of Investigations
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Results 1 - 10 of 20
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1/1/1990 - Reports of InvestigationsThe Bureau of Mines preproduction wireless survey system (WSS) and its performance during an in-mine test are discussed in this report. The WSS was developed to reduce downhole surveying time in order to increase the efficiency of drilling long horizont...
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1/1/1988 - Reports of InvestigationsThis Bureau of Mines report investigates the horizontal trajectory of boreholes drilled in coalbeds using the rotary drilling technique.
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1/1/1987 - Reports of InvestigationsStimulated 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...
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1/1/1987 - Reports of InvestigationsDescribes 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.
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1/1/1986 - Reports of InvestigationsThe 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...
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1/1/1985 - Reports of InvestigationsThis Bureau of Mines report describes and compares the procedures, capital investments, and operating costs of rotary and in-hole motor drilling techniques used to drain methane gas from the Pittsburgh coalbed in an underground mine located in southwest...
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1/1/1985 - Reports of InvestigationsThe cross-measure borehole technique is an effective method of controlling methane liberated by fracturing the roof strata in longwall gobs where overburden is less than 750 ft (229 m). About 71 pct of the methane produced by longwall mining in the Lowe...
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1/1/1984 - Reports of InvestigationsMethane-drainage holes must be completely filled by grout before mining to prevent the emission of large quantities of gas during mine-through, which would constitute an explosion hazard. In November 1980, seven horizontal holes at the multipurpose bore...
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Probability of Encountering Coalbed Discontinuities During Vertical and Horizontal Borehole Drilling1/1/1982 - Reports of InvestigationsProbabilities 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...
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1/1/1980 - Reports of InvestigationsThe 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...
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Content source: National Institute for Occupational Safety and Health, Mining Program