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oa Constraining the Stress Tensor from Microseismicity Focal Mechanisms at Decatur
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, World CCUS Conference 2025, Sep 2025, Volume 2025, p.1 - 5
Abstract
Induced microseismicity in the Decatur CO2 storage project provides critical constraints on the in-situ stress state. We apply the full stress inversion to source mechanisms data from induced seismic events, incorporating additional stress constraints from vertical stress (Sv) and Instantaneous Shut-in Pressure (ISIP) values. The minimal activation pressure is then evaluated using inverted stress tensor. The estimated minimum activation pressure suggests three possible scenarios: lower-than-expected ISIP at the depth of events (∼28–29 MPa), an extremely high maximum horizontal stress (>120 MPa), or a low friction coefficient on activated faults. Furthermore, poorly constrained source mechanisms lead to unreliable stress estimates, even when varying ISIP and Sv values. These findings highlight the need for accurate stress measurements and well-constrained source mechanisms to improve the prediction of induced seismicity in future CO2 storage projects.