Development and validation of a model fo
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Philip W. Johnson; William C. Lyons
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Article
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1992
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Elsevier Science
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English
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The pneumatic turbine-powered drilling engine (PTDE) is a unique tool for directional drilling when using air or gas as the drilling fluid. The engine consists of a pneumatic turbine motor coupled to the bit by a four-stage planetary gear transmission and a thrust-bearing assembly, and is supported