Electrical methods in exploration for oil and minerals

The electrical methods which can be applied in resource exploration are highly diverse in theory and practice. However, the bulk of exploration effort is carried out with four relatively standardized methodologies; direct-current resistivity sounding, induced polarization sectioning, magnetotelluric sounding and time-domain electromagnetic sounding. The direct-current and induced polarization methods are in a mature stage of development, although in recent years, the capabilities of these two methods have been markedly improved through the incorporation of digital data acquisition equipment and computer-based interpretation schemes. The magnetotelluric method may well be approaching maturity in development, but it has only been within the past few years that data acquisition and interpretation have progressed to the point where consistently reliable results can be obtained. The electromagnetic methods are in a very rapid state of development, and may well be among the most powerful of geophysical techniques when their capabilities are fully realized.