These electrotelluric surveys assist in identifying geological structures and lithologies, and, under ideal conditions, will detect the presence of oil and gas. Small-scale structures, structural displacements and lateral/ vertical variations in lithologies can be defined. Collected data can be used for stratigraphic correlation, porosity geometries and, to some degree, reserve estimation. Geologic and isopach maps, three-dimensional stick diagrams, cross sections and other graphical analyses can be developed from the collected data.