Relative contribution to signal by ground elements in two-coil induction logging system
A. Roy and R. L. Dhar
Journal name: Geophysical Prospecting
Issue: Vol 18, No 3, September 1970 pp. 389 - 404
Info: Article, PDF ( 739.4Kb )
A two-coil induction logging system in an infinite homogeneous medium has been theoretically analysed for the relative contributions of various ground elements to the total signal at the receiver. Unlike an earlier approximate treatment by Doll (1949), the present analysis takes skin effect into account (while neglecting displacement currents). Contour diagrams depicting relative contributions from every ground point and diagrams for vertical and radial/lateral investigation characteristics are presented. The results differ significantly from Doll's in the following points:
The possibilities of a horizontal-horizontal sonde is briefly examined and found to be inferior to the usual sonde because of its higher sensitivity to the mud column and the invaded zone.