ELECTROMAGNETIC FORMATION EVALUATION TOOL APPARATUS AND METHOD.

摘要

Apparatus and methods are described, such as for obtaining information indicative of a formation resistivity using an electromagnetic formation evaluation tool apparatus. For example, the electromagnetic formation evaluation tool apparatus includes exciter electrodes configured to transmit and receive a formation current. A first exciter electrode may be insulated from a conductive apparatus housing and a second exciter electrode may be coupled to the conductive apparatus housing. Monitor electrodes may be insulated from the conductive apparatus housing. A receiver circuit may be coupled to the monitor electrodes and configured to measure a voltage differential between the monitor electrodes. A power amplifier circuit may be coupled to the first exciter electrode and the conductive apparatus housing and configured to generate the formation current wherein the conductive apparatus housing provides a return path to the power amplifier circuit for the formation current.