electrode device — Oil & Gas Glossary
A logging tool based on an arrangement of simple metallic electrodes working at low frequency (less than 500 Hz). The term includes conventional electrical logs, laterologs, micrologs and other microresistivity logs. Electrode devices are used for both wireline and measurements-while-drilling logs. In all electrode devices, a current (IO) and a voltage (VO) are measured on the appropriate electrodes or combinations
Detailed Explanation
of electrodes. The apparent formationresistivity is then determined by: Ra = K VO / IO, where K is a system constant for the device concerned.