Equivalence Verification of the Induced Polarization and Complex Resistivity Dispersion in the Core

The induced polarization and complex resistivity dispersion were broadly applied in mineral and petroleum exploration, respectively. Although some petrophysicists has aware of some intrinsic relationship between the two petrophysical phenomena, no one has verified it by petrophysical experiments. The complex resistivity spectrum and the induced polarization spectrum of seven columnar artificial sandstone cores were measured by the impedance analyzer and measurement system designed ourselves to verify the intrinsic relationship between the two phenomena. There is a high positive correlation between the induced chargeability and the complex resistivity chargeability, and they all have good negative correlation with the core pore structure index. Based on the Cole-Cole model which is well known as a good description of the dispersion characteristics of rock, the response equation of the equivalent circuit under induced polarization excitation was derived and the equivalence between the induced chargeability and the complex resistivity chargeability was proved too. Moreover, the chargeability obtained by fitting the induced polarization measurement data according to the response equation has higher accuracy. These new insights have a great significant for extending the application of two petrophysical phenomena in minerals and petroleum exploration.