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Preparatory Work for the Seismic Monitoring of CO2 Storage at a Prospective Site in the St. Lawrence Lowlands, Canada
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 76th EAGE Conference and Exhibition 2014, Jun 2014, Volume 2014, p.1 - 5
Abstract
The success of the geological storage of CO2 depends on the capability to monitor movements of the injected fluid into the subsurface. For understanding the effects of CO2 as a pore fluid on the overall rock seismic response, a series of ultrasonic measurements on two samples of saline aquifer sandstones of the Potsdam Group have been made showing clear P-wave variations with CO2 varying phase state.
Significant amplitude variation was only observed in the Covey Hill sample. The laboratory measurements and well log data were used to calibrate a numerical model that was used to perform poro-viscoelastic forward modeling of time-lapse walkaway VSP surveys. The results show that supercritical CO2 injected in the reservoir, results in a clear seismic signature. Finally, the modeling results also indicate that the possibility to rely on AVO analysis to monitor the CO2 plume is compromised by a refracted wave that appear early in the wave field.