Deformation Prediction in the Otway Basin - A Seismo-mechanical Workflow for Sub-/seismic Fault Detection
C.M. Krawczyk, D.C. Tanner, J. Ziesch, T. Beilecke and A. Henk
Event name: The Third Sustainable Earth Sciences Conference and Exhibition
Session: Geophysical Characterization and Monitoring
Publication date: 13 October 2015
Info: Extended abstract, PDF ( 1.28Mb )
Price: € 20
The main challenge of assuring long-term storage integrity and providing sensitive monitoring strategies in the framework of CO2 injection is to unravel the specific potential of communicating systems that occur between reservoir and surface. For this purpose, the joint project PROTECT (PRediction Of deformation To Ensure Carbon Traps) developed a seismo-mechanical workflow to predict and quantify the distribution and the amount of sub-/seismic strain in the proximity of the CO2 reservoir in the Otway Basin. The sub-seismic space is filled by different, integrated approaches that encompass seismic attributes, retro-deformation, and numerical forward modelling. While the attributes image small lineaments, the retro-deformation shows that, in the seal, ca. 20-30 % strain magnitude on average, with extremes of 80 % along certain lineaments. Locally, the minimum horizontal stress at reservoir is overprinted by faults, as evidenced by numerical modelling. We calibrated our predictions with shear-wave reflection seismics that evidences areas of sub-seismic faulting. Thus, the workflow reveals possible migration pathways, and as such provides a tool for prediction and adapted time-dependent monitoring for subsurface storage in general.