Geophysical Research Letters

On the origins of self-potential (SP) anomalies induced by water injections into geothermal reservoirs

Authors

Errata

This article is corrected by:

  1. Errata: Correction to “On the origins of self-potential (SP) anomalies induced by water injections into geothermal reservoirs” Volume 33, Issue 20, Article first published online: 31 October 2006

Abstract

[1] 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.

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