Method of interpreting impedance distribution of an earth formation penetrated by a borehole using precursor data provided by a moving logging array having a single continuously emitting current electrode and a multiplicity of potential electrodes

Abstract From the Canadian patent

In accordance with the present invention a, method is disclosed for synthesizing the true response characteristics of a combination of different hole-centered electric logging tools in a variety of difficult borehole conditions as provided by (1) determining impedance values of an earth formation penetrated by a borehole filled with a drilling mud of resistivity (Rm) and, (2) selectively manipulating the impedance values as impedance entries of a series of reciprocal matrices so as to synthesize operations of different hole-centered tools over an associated depth increment with surprising accuracy. Each of the reciprocal impedance matrices is associated with a reciprocal matrix gather …