METHOD FOR RADIAL PROFILING OF RESISTIVITY AT MULTIPLE DEPTHS OF INVESTIGATION

摘要

A resistivity tool (100) suitable for use in a borehole and configured to obtain a resistivity radial profile at multiple depths of investigation in a geological formation comprises a receiver pair (R1, R2) and an array of transmitters (T1-T3). The distance of each transmitter from the receivers corresponds to a particular depth of investigation into the formation. Using as few as two transmitters, the resistivity tool derives resistivity values at any number of depths of investigation, including depths of investigation that do not correspond to transmitter/receiver spacings on the tool. A measurement processor (204) combines signals received from the existing transmitters using linear interpolation, geometric interpolation, and/or other techniques to derive the resistivity measurements.