f Vertical electric imaging: a new technique to image electric reflectivity near borehole

Electric Jogging techniques have been widely used to investigate resistivity structure along a borehole. Since they use only in-hole electrodes, common electric logs provide no information about the inclination or the orientation of resistivity structure. In addition, the investigation depth is usually limited. Although electrical cross-hole imaging techniques have been recently developed (e.g., Shima,1990), they require complex analyses and much calculation time . I propose a new technique that provides an electric reflectivity image near a borehole. In the measurement, the vertical component of the electric field generated by a surface electrode is measured by three borehole electrodes.