METHOD FOR TRANSMITTING A HIGH COUNT RATE PULSE SIGNAL OVER A COMMON WELL LOGGING CABLE

摘要

METHOD FOR TRANSMITTINGA HIGH COUNT RATE PULSE SIGNALOVER A COMMON WELL LOGGING CABLE(D#74,052-FD])ABSTRACT OF THE DISCLOSUREA conventional type radiation detector in cooper-ation with a photomultiplier tube provides data pulses ofone polarity, corresponding in peak amplitude and number todetected radiation in a borehole traversing an earth for-mation. Each data pulse is effectively converted to twopulses of different polarities, with one pulse starting whenthe other is completed and transmitted over a common welllogging cable. The creation of a second pulse of anopposite polarity cancels out the low frequency componentof the pulse so that they arrive at the surface as a pulseof a single polarity having a very short tail and a fastrise time. This permits more pulses to be transmittedwithin a given time period than heretofore existed.Surface electronics process the transmitted pulses toprovide a record of the sensed condition in the borehole.I