Inversao De Multiperfis Verticais De Ip-Resisitividade Obtidos Ao Longo De Paredes Rochosas

Apparent resistivity and induced polarization Schlumberger multiprofiles were obtained along vertical cliffs cutting a shaly sandstone sequence. These measurements, designed to explore depths of about 2 m from the walls, are to be used in the petrophysical characterization of the sandstones. First, the resistivity data were one-dimensionally inverted as conventional geoelectrical soundings. Then, the apparent chargeabilities were converted to the intrinsic chargeabilities of the different media by solving a system of overdetermined linear equations, written according to Seigel’s (1959) mathematical formulation. These procedures can also be applied to 2-D or 3-D earth models. The interpreted results are quite satisfactory and can be used to recognize changes in clay content and in water saturation along a profile.