BOREHOLE LOGGING APPARATUS FOR DEEP WELL DRILLING WITH A DEVICE FOR TRANSMITTING BOREHOLE MEASUREMENT DATA

摘要

The invention is directed to a borehole logging apparatus for deep welldrilling, with asignal transmitter for transmitting measured data obtained while drilling froma boreholethrough the drilling fluid to the earth's surface, and with an elongatedhousing which is adaptedfor insertion in the drilling fluid conduit of a drill string. Accommodated inthe housing is a flowregulator with a control piston, which controls the cross-section of openingof a bypassopening in response to the pressure differential generated at an entranceopening of thehousing and the force of a spring, in such manner that the part of thedrilling fluid currentdelivered to the housing conduit, which is fed to the signal transmitter, ismaintainedsubstantially constant, and the remaining excess drilling fluid current isrouted to the drillingfluid conduit via the bypass opening.