Patent ID: 8633701

Claim:
An apparatus configured to estimate a value of a resistivity property of an earth formation, comprising: a carrier configured to be positioned in a borehole in the earth formation, comprising: at least one return electrode configured for capacitive coupling to a circuit including the earth formation and a source of a plurality of measurement signals, and configured to produce a response to each of the plurality of measurement signals at a plurality of frequencies; and a processor configured to use the produced responses from the at least one return electrode and configured to calculate a phase-sensitive impedance value for each of the produced responses and to estimate the value of the resistivity property from one of selected produced responses, the selected responses corresponding to frequencies within a predetermined range above and below an estimated value of a resonance frequency of the circuit, the processor further configured to obtain the estimated value of the resonance frequency by identifying one of the produced responses having a corresponding phase-sensitive impedance value with an absolute value of its reactive component smaller than an absolute value of a reactive component of each of the phase-sensitive impedance values corresponding to the other produced responses.