New developments in conventional hydrocarbon exploration with electromagnetic methods

Over recent decades, electromagnetic methods have been viewed with considerable suspicion by many in the hydrocarbon exploration industry. While highly effective in mineral and environmental geophysics, electro m a g n e t i c methods have played a minor role in hydrocarbon exploration. Since electromagnetic (EM) methods use signals that diffuse in the Earth, they cannot provide the same vertical resolution as modern seismic exploration. However, in the last decade, electromagnetic methods in general, and magnetotellurics (MT) specifically, have become more widely used in hydrocarbon exploration. This change is clearly not due to any change in the underlying physics but is due to: