Abstract

By using a low-frequency AC method based on lock-in amplification, electrokinetic response in porous rock can be accurately measured with high sensitivity. With this method, we have measured streaming potentials as small as 300 nV and electroosmotic pressures as low as 10 Pa. We describe our technique, and discuss the results from a suite of 12 brine-saturated samples, consisting of six sandstones, two carbonates, and four fused glass bead specimens. We show that the permeability of the rock may be derived exactly from the electrokinetic transport coefficients and sample conductivity. This result is verified experimentally for all NaCl concentrations. The electrokinetic response as a function of concentration and temperature has been measured and is compared with predictions from the Debye–Hückel model and Helmholtz–Smoluchowski equation in the thin-layer limit.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.