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Seismic Monitoring of CO2 Geosequestration - CO2CRC Otway Case Study Using Full 4D Elastic Modelling
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 78th EAGE Conference and Exhibition 2016, May 2016, Volume 2016, p.1 - 5
Abstract
Stage 2C of the Otway project conducted by the CO2CRC Limited is focused on seismic monitoring of a small-scale injection of CO2-rich gas into a saline aquifer. Design of the monitoring program is based on a series of simulations conducted in 2007–2014. The gas plume is likely to be small in size and the contrast in elastic properties is also predicted to be relatively low. To maximise chances of detection the low-amplitude time-lapse signal we test the current processing workflow on synthetic datasets for the entire baseline and monitor surveys. The datasets were obtained by elastic 3D FDTD modelling approach for the actual field acquisition geometry and the most realistic model of the subsurface and gas plume. To this end, we built a full-earth static geological model of the site with resolution typical for reservoirs in petroleum geology. The analysis of the synthetic datasets gives an estimate of the magnitude of the time-lapse signal and illustrates effects of the conventional processing procedures on the signal in the presence of the bandlimited random noise. We have found that the anticipated intensity of the time-lapse signal is comparable to the average intensity within the target interval, and hence should be detectable.