Multifrequency signal transmitter with attenuation of selected harmonies for an array induction well logging apparatus

摘要

A transmitter for an induction well logging tool, adapted to be disposed in the borehole of an oil well, develops an output signal for energizing the borehole formation which inherently consists of six separate signal components, the six components including four primary signal components which simultaneously energize the borehole formation inducing in the formation four primary eddy currents. These four primary eddy currents are detected by the array induction tool receiver, the received signals being used to determine the resistivity and conductivity of the borehole formation.