Potential of Ambient Seismic Noise Techniques To Monitor Injection Induced Subsurface Changes


Abstract eng:
One of the key challenges for the successful developement and operation of deep underground heat exchangers is to control the risk of inducing potentially hazardous seismic events. This was once again highlighted with the failures of two recent deep geothermal energy projects in Switzerland (Basel, 2006, St. Gallen, 2013). We study tiny lapse-time changes in the coda of ambient noise cross-correlations recorded over 1 year including the different project phases. We observe a significant loss of waveform coherence of our measurements that starts with the onset of the fluid injections 4 days prior to the gas kick. We can horizontally and vertically constrain the waveform perturbation to the injection location of the fluid. We interpret the loss of coherence as a local perturbation of the medium due to the fluid injections. Using this case, we show how an ambient seismic noise analysis can be used to assess the aseismic response of the subsurface to well operations and how this method could have helped to recognize the unexpected process much earlier than the microseismic response allowed.

Conference Title:
Conference Title:
16th World Conference on Earthquake Engineering
Conference Venue:
Santiago (CL)
Conference Dates:
2017-01-09 / 2017-01-13
Rights:
Text je chráněný podle autorského zákona č. 121/2000 Sb.



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 Record created 2017-01-18, last modified 2017-01-18


Original version of the author's contribution as presented on USB, paper 3267.:
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