RESEA RCHES ON THE TECHNIQUE OF DIRECTIONAL DRILLING ALONG COAL SEA MS
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Graphical Abstract
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Abstract
Some technical problems about directional drilling along coal seams were' successfully solved by use of screw, wire and compound drilling tools, and optimum drilling parameters. In the directional test drilling along median to thick and low angle coal seams, the total drilling course reached a distance of 2213.56 m and the maximum drilling depth is 302 m.
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