Seismic hazard due to fluid injections
- 1University of Calgary, Department of Physics and Astronomy, Calgary, Canada (davidsen@phas.ucalgary.ca)
- 2University of Calgary, Department of Physics and Astronomy, Calgary, Canada (cole.lordmay@ucalgary.ca)
- 3University of Calgary, Department of Physics and Astronomy, Calgary, Canada (jordibaro@gmail.com)
- 4Centre for Mathematical Research, Barcelona, Spain (jordibaro@gmail.com)
- 5University of Calgary, Department of Geosciences, Calgary, Canada (eatond@ucalgary.ca)
Earthquakes can be induced by natural and anthropogenic processes involving the injection or migration of fluids within rock formations. A variety of field observations has led to the formulation of three different and apparently contradicting paradigms in the estimation of the seismic hazard associated with fluid injections. Based on a unified conceptual model accounting for the non-homogeneous pore-pressure stimulation caused by fluid injection in a prestressed region, we show here that all three paradigms naturally coexist. The loading history and heterogeneity of the host medium determine which of the three paradigms prevails. This can be understood as a consequence of a superposition of two populations of events triggered at different pore-pressure levels with different Gutenberg-Richter b-values.
How to cite: Davidsen, J., Lord-May, C., Baro, J., and Eaton, D.: Seismic hazard due to fluid injections, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-6334, https://doi.org/10.5194/egusphere-egu2020-6334, 2020
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Thank you for the informative slides on your model.
I'm wondering how your model will behave if the a certain set of elements (grouped in close spatial proximity) has a higher slip potential? Or, if there was a region with perhaps lower strength (from e.g. locally low friction coefficent), would this affect the three types of observed behavior? The reason I ask stems from the case where a large, preexisting structure is not seen and is activated by the anthropogenic activities. Would this perhaps influence the seismic behavior in the model?
Also, perhaps I missed something in the slides, apologies if that's the case.
dear Paul Selvadurai,
thank you very much for your comment.
Indeed, this is a very interesting point. Some of our early tests were in this direction and your intuituion is absolutely right: we observed a behaviour that we can link to triggered seismicity.
We simulated a geological feature consisting in a critically loaded region close to the injection site, while the rest of the system was initiated at subcritical stress levels. We initially observed the expected superposition between populations I and II, until the geological feature is reached by the stimulated area. Then, we did find a short sequence of critical events, or population III. It was short because of finite size effects. Even though, it did resemble the statistics you would expect as triggered seismicity, with a certai similute with the sequence in Pohang, for example.
Thank you very much! This model is very interesting. Has it been published yet?
Thanks for your appreciation! This work is currently under revision at Physical Review Letters. Best case scenario, we are still a few months for publication.
Knowing that this is a global event, If you have any question but this is not the right time for you, you can ask me about this display as well at: open at 14:00-15:45 CET
https://meetingorganizer.copernicus.org/EGU2020/session/34890
Ignore the previous comment. If you have any question, please leave the comment here and I'll try to address it ASAP.