Introduction to downhole electromagnetic methods

Abstract

During the past decade, downhole electromagnetics (DHEM) has become a very important exploration method for conductive mineralisation, particularly in areas where the ability of surface EM to define a target is limited either by large depths or by interfering conductive bodies such as overburden, shallow sulphides and peripheral mineralised horizons. However, despite the rapid development of computer aided DHEM interpretation techniques, many anomalous DHEM profiles are either misinterpreted or left uninterpreted because of a lack of experience with the method in the general geophysical community. The purpose of this special issue of Exploration Geophysics is to help with this problem by publishing articles illustrating some successes and problems in the application of DHEM, as well as its potential as an ore finder. This volume has evolved from the ASEG Workshop on Downhole Electromagnetics held in Melbourne on 2 and 3 December, 1985.