| 摘要 |
A system for use in providing measurements from within a borehole to the earth's surface during drilling operations in which a drill pipe extends from the earth's surface having a drilling means, such as a drill bit, at the lower end and a fluid circulation system forming a column of drilling fluid within the drill string, a direct radiator telemetering system including a housing positioned within the drill string providing for the flow of drilling fluid therepast, the housing being in the form of a tubular member having within it an electrically driven pressure pulse radiating means responsive to electrical signals representing the magnitude of a downhole parameter for producing a sequence of pressure pulses indicative of the magnitude, the tubular housing being of a relatively long length being of approximately a substantial fraction of the equivalent wavelength of the pulses produced by the pulse producing means, and instruments at the earth's surface for maintaining superatmospheric mud pressure in the top of the drill string and for detecting the pressure pulses to provide a measure of the magnitude of the parameter.
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