Method of interpreting impedance distribution of an earth formation obtained by a moving array using end emitting current electrodes sequentially activated and a series 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 matrix so as to synthesize operations of different hole-centered tools over an associated depth increment with surprising accuracy. Each of the impedance matrices is associated with a matrix gather indexed to one of a series of finite, overlapping …