Complex resistivity spectra for estimating permeability in dolomites from the Mississippian Madison Formation, Wyoming

Analyses of CRS are performed on brine-saturated core plugs in a log sweep from 0.1- 100,000 Hz with a four-electrode setup at varying confining pressures. Results show that the frequency dispersion of CRS between 10 and 100 kHz is directly related to the porosity in these dolomites. The phase shift of CRS shows high variance in both low and high porosity samples with characteristic slopes βPhase and βAmplitude for frequencies between 10 and 100 kHz. Modifying an empirical model of Tong & Tao (2008) to include porosity and both βPhase and βAmplitude can predict permeability with a correlation coefficient of R2 = 0.84.