Patent ID: 9568636
Date: 2017-02-14
CPC Classifications: G01V

Claim:
1. A method of investigating a formation surrounding a borehole, comprising: computing both an average in-phase current and an average out-of-phase current for each pad disposed on a down-hole tool by repeatedly acquiring in-phase and out-of-phase current data from the formation relative to a voltage applied to one or more electrodes disposed on said pad over multiple depths within a depth window; averaging the acquired in-phase and out-of-phase current data over the one or more electrodes to obtain the average in-phase current and the average out-of-phase current for each pad at each depth of the multiple depths within the depth window; determining an average phase shift compensation angle from each respective phase shift compensation angle calculated for each pad of the down-hole tool; applying the average phase shift compensation angle determined to in-phase and out-of-phase current data subsequently acquired by each pad of the down-hole tool from the formation over a depth of the borehole to be measured to obtain phase shift compensated current values over the depth of the borehole to be measured; and forming an image of the borehole based on the phase shift compensated current values.