METHOD AND APPARATUS FOR RESISTIVITY IMAGING IN BOREHOLES FILLED WITH LOW CONDUCTIVITY FLUIDS

摘要

A mixed mode tool uses an inductive source and detects galvanic currents and/or potentials at electrodes in proximity to a borehole wall to produce a resistivity image of the earth formation. Alternative, the magnetic field produced by a galvanic current is detected by an antenna coil and used to produce a resistivity image.