Quantification of Surface Conductivity in Clean Sandstones


John F. Evers, Babu G. Iyer,
University of Wyoming

5th Formation Evaluation
Symposium of the Canadian Well Logging Society in Calgary, May 5 – 7,



Many investigators have noted that the apparent formation factor of porous materials seems to diminish as the interstitial waters become more resistive. This effect has been attributed both to the presence of "con- ductive solids" (usually clays) and to the existence of a concentrated layer of ions attracted to the surfaces of the rock matrix.