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- Tasks and activities:
- Drilling
- Document types:
- Reports of Investigations
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Results 1 - 9 of 9
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7/1/2002 - Reports of InvestigationsThe process of drilling and bolting the roof is currently one of the most dangerous jobs in underground mining, resulting in about 1,000 accidents with injuries each year in the United States. Researchers from the Spokane Research Laboratory of the Nat...
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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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1/1/1987 - 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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1/1/1982 - Reports of InvestigationsThree long horizontal holes were drilled from a directionally drilled surface hole at the Emerald Mine near Waynesburg, Pennsylvania. The purpose was to adapt the technique of directional drilling for use in draining methane from coalbeds.
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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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1/1/1979 - Reports of InvestigationsThe Bureau of Mines is cooperating with the U.S. Department of Energy in a directional degasification project at the Emerald Mine near Waynesburg, Pennsylvania. This project is designed to combine the highly successful underground horizontal degasificat...
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1/1/1977 - Reports of InvestigationsA 3-inch pilot hole was directionally drilled to intercept the Freeport coalbed horizon horizontally at Mather, Pennsylvania, as part of a Bureau of Mines degasification project. The original concept was to continue the horizontal drilling into the coal...
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1/1/1976 - Reports of InvestigationsThe 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...
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1/1/1975 - Reports of InvestigationsCoal is a soft and brittle material. Drilling rates in the Pittsburgh coalbed using a drag bit exceed 3 ft/min at 2,500-pound thrust. However, maintaining the bit on a horizontal trajectory or parallel to bedding planes to attain lengths of 1,000 feet i...
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Content source: National Institute for Occupational Safety and Health, Mining Program