On the origins of self-potential (SP) anomalies induced by water injections into geothermal reservoirs
Article first published online: 14 OCT 2004
Copyright 2004 by the American Geophysical Union.
Geophysical Research Letters
Volume 31, Issue 19, October 2004
How to Cite
2004), On the origins of self-potential (SP) anomalies induced by water injections into geothermal reservoirs, Geophys. Res. Lett., 31, L19609, doi:10.1029/2004GL020922., , and (
- Issue published online: 14 OCT 2004
- Article first published online: 14 OCT 2004
- Manuscript Accepted: 15 SEP 2004
- Manuscript Revised: 25 AUG 2004
- Manuscript Received: 5 JUL 2004
Vol. 33, Issue 20, Article first published online: 31 OCT 2006
 Stimulated fluid flow in geothermal reservoirs can produce surface Self-Potential (SP) anomalies of several mV. A commonly accepted interpretation involves the activation of electrokinetic processes. However we can not rule out electrochemical or electrothermal processes generated by the differences in chemical composition and temperature between the in-situ and injected fluids. We analyzed the relative contribution of electrokinetic, electrochemical and electrothermal potentials to the SP anomalies observed above the Soultz-sous-Forêts geothermal reservoir while injecting cold fresh water. We found that electrokinetic effects were dominant during the stimulation phase (injection rates larger than 30 kg s−1) and that electrochemical and electrothermal effects became significant at small injection rates (less than 10 kg s−1) and after shut-in.