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Interpretation of Electrical Properties for Humid and Saturated Hematitic Sandstone Sample
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 68th EAGE Conference and Exhibition incorporating SPE EUROPEC 2006, Jun 2006, cp-2-00104
- ISBN: 978-90-73781-00-9
Abstract
Effects of water saturation on electrical properties, of humid, partially, and satrurated hematitic sandstone sample, were investigated experimentally. These data were discussed theoretically using models that account for the electrical polarization. We change the saturation of a hematitic sandstone sample from normal relative humidity (~50 RH) to fully saturated. Complex impedance measurements were performed in the frequency range from 1 Hz to 100 KHz. Experimental data indicates that the electrical properties vary strongly with water saturations. As the frequency increases the rate of dielectric constant change decreases and the change is nearly constant at high frequencies. The rate of decrease of the dielectric constant with frequency decreases as the water saturation decrease. The changes of the electrical properties due to saturation were attributed to the ionic surface charge at grain interface. The interaction between the matrix of a porous material and a small quantity of water located in its pore space induces polarization phenomena and enhances the charge transport. The results can be explained as proton conduction in the humid case and low saturations and electrolytic conduction along with protonic transport in the fully saturated case.