Patent ID: 9239402
Filing Date: 2016-01-19
CPC Classification: G01V

Claim Text:
1. An apparatus comprising: a main electrode of a tool, the main electrode having a number of spaced apart electrodes within the main electrode, the spaced apart electrodes arranged azimuthally with respect to an axis of the tool; a first number of electrodes to one side of the main electrode along the axis and a second number of electrodes on another side of the main electrode along the axis; a number of monitor electrodes arranged along the axis of the tool from the main electrode such that voltages to the number of monitor electrodes are operatively controlled with respect to current operatively generated from the spaced apart electrodes of the main electrode; and a control unit to operatively control generation of a current pattern selected from a plurality of modes, each mode having current generated from the main electrode, from one or more electrodes of the first number of electrodes to only one non-current generating electrode of the first number of electrodes, the one non-current generating electrode operatively selected according to the mode, and from one or more electrodes of the second number of electrodes to only one non-current generating electrode of the second number of electrodes, the one non-current generating electrode operatively selected according to the mode, wherein at least one mode of the plurality of the modes has a plurality of non-current generating electrodes selected from each of the first number of electrodes and the second number of electrodes.