Patent Document ID: 7756642
Application ID: 11769031
Patent Flag: 1

Claim One:
1. A method of characterizing an earth subterranean structure using a measurement assembly including electromagnetic (EM) receivers and one or more EM sources, the method comprising: receiving at a data processor measured voltage data collected by the EM receivers in response to transmission by the one or more EM sources; computing, based on a formation model, predicted EM data; iteratively performing inversion according to a cost function that computes a difference between the measured voltage data and a product of a term a ratio of predicted data for different EM sources or EM receivers and a term containing a correction factor for distortion caused by an electrically conductive lining structure at the EM receivers and the one or more EM sources, the term containing a ratio of distortion data for different EM sources or EM receivers, wherein iteratively performing the inversion solves for parameters of the formation model and the correction factor for distortion caused by an electrically conductive lining structure at the EM receivers and the one or more EM sources; and generating at a display an image of the resistivity, in the formation based on the inversion accounting for the distortion caused by the electrically conductive lining structure at the EM receivers and the one or more EM sources.