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oa Geomechanical Modelling of Fault Reactivation Risks Associated with CO2 Injection in the Cooper-Eromanga Basins (Australia)
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, World CCUS Conference 2025, Sep 2025, Volume 2025, p.1 - 4
Abstract
Carbon capture and storage (CCS) is essential for enabling decarbonisation but quantifying the risk of injection-related fault reactivation is a barrier to global upscaling. The Cooper and Eromanga Basins are becoming a focus for CCS and recent reprocessing of >44,000 km of 2D seismic and the generation of 2Dcubed ™ (pseudo-3D) volumes via structurally-conformable interpolation provides a unique dataset for rapid regional interpretation and screening of candidate CCS sites. Results feed into assessments of the geomechanical risks and operating limits for CCS. This study reviewed the validity of using the pseudo-3D volumes for this type of screening via separate interpretations of 2D, pseudo-3D and ‘genuine’ 3D seismic. Mapped faults were converted to depth and various geomechanical risking parameters assessed. In the study area, faults don’t penetrate above the regional topseal but downward pressure-transmission and reactivation of deep-seated faults is a risk. Poor imaging due to multiple coals means that fault interpretation can be ambiguous and we found notable downdip geometrical variability between faults picked on different volumes and by different interpreters. Interpreted fault strikes and lateral dimensions were more consistent. Assessment of fault reactivation likelihood highlights the sensitivity of outcomes to fault dip, with ramifications for CCS site appraisal.
