Efficient Physics-based Modelling of Induced Seismicity Decatur CCS Project and Upscaling to the Illinois Basin
Description:
To enable worldwide scalable development of carbon sequestration in saline aquifers, we need to assess (i) the risks of induced faulting and seismicity, (ii) the associated risk of leakage, and (iii) basin-scale interactions between projects. We focus on the Illinois basin which hosted the Decatur CCS project and that will potentially be. hub for commercial scale CCS projects. Seismic activity was reported near the Decatur CCS1 site (first pilot injection site), but corrections to the injection strategy have reduced the earthquake rate for larger injections in the nearby Decatur CCS2 project (second injection site for commercial purposes). We use statistical and physics-based modeling to determine whether these earthquakes were directly caused by the injection process, tectonic loading, or inter-earthquake triggering. Our approach involves a modular, computationally efficient, physics-based, workflow to simulate the effects of fluid injection in subsurface reservoirs, their geomechanical deformation, and seismicity generation. We find a strikingly high spatio-temporal correlation between earthquakes attributed to fluid injection and the Coulomb stress changes from our model. The strength excess in the faults that hosted these earthquakes is remarkably low, indicating that the faults in the basement were critically stressed despite the tectonically quiet setting. We further use our model calibrated with CCS1 to hindcast seismicity in CCS2 and find remarkable agreement with the low observed rates of seismicity, confirming that injections in formations hydraulically separated from the basement will result in low seismicity rates. Finally, we expand our analysis using scenarios for large scale CCS in the Illinois basin (20+ injection wells) and provide potential seismicity scenarios. Overall, our tool for seismicity forecasting can enlighten regulations for CO2 sequestration.
Session: From Physics to Forecasts: Advancements and Future Directions of Induced Seismicity Research - II
Type: Oral
Date: 4/15/2025
Presentation Time: 11:15 AM (local time)
Presenting Author: Mateo
Student Presenter: No
Invited Presentation:
Poster Number:
Authors
Mateo Acosta Presenting Author Corresponding Author acosta@vt.edu Virginia Polytechnic Institute and State University |
Guillaume Salha gsalha@caltech.edu California Institute of Technology |
Charles Forestier cforesti@caltech.edu California Institute of Technology |
Guanli Wang gwwwang@caltech.edu California Institute of Technology |
Jean-Philippe Avouac avouac@caltech.edu California Institute of Technology |
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Efficient Physics-based Modelling of Induced Seismicity Decatur CCS Project and Upscaling to the Illinois Basin
Session
From Physics to Forecasts: Advancements and Future Directions of Induced Seismicity Research