ABSTRACT
A system can be designed for a specific purpose, such as deep, medium, shallow, or very-shallow investigation, specific volume investigation, thin-bed accuracy, high or low resolution, high-resistivity use, and / or various combinations of these features. The measurement is a single-point resistivity measurement with deep investigation, high resolution, and stable geometry. The spherically focused log system uses two independent current systems one of which establishes constant potential, spheroid guard shells around the measure electrode. The guard current system prevents a flow of measure current up and down the borehole and establishes the equipotential spheroids. The original sidewall focusing electrode system was the Microlaterolog, Microlaterolog. An unofficial name, at the time, was the “Trumpet” log, because the measure current pattern is shaped like a trumpet. The Atlas Wireline device is called the Micro Laterolog. Forxo is the older name for the Dresser Atlas device.
