CALIBRATION METHOD FOR A MICRORESISTIVITY LOGGING TOOL

摘要

Methods (300,400) for making calibrated microresistivity logging measurements in nonconductive drilling fluid are disclosed. A calibrated measurement parameter (e.g., a calibrated electrical impedance (Zcal) or a calibrated potential difference (?Vcal);) is obtained and further utilized to compute a formation resistivity (R). The methods (300,400) tend to be particularly well suited for drilling applications in which the borehole (40) environment is highly resistive (i.e., boreholes (40) in which both the drilling fluid and the formation have a high resistivity).