Electromagnetic induction well-logging device

摘要

An electromagnetic induction well-logging system for measuring the combined effect of electrical conductivity and magnetic susceptibility in a highly conductive and highly magnetic orebody, using a transmitting and receiving coil (6) in a borehole probe which operates on a time domain system to produce and then sense eddy currents in the surrounding ore. A timing circuit (24) generates a series of two identical timing pulses between successive primary electric pulses of the time domain system. A differentiating means (32) receives the signals from the coil and timing circuit, and compares the signals to provide a relative measurement of combined conductivity and susceptibility of the orebody.