Utilization of seismic attenuation in the monitoring of CO2 geological storage project

Abstract

Aiming quantitative monitoring of subsurface in CO 2 geological storage project, this paper presents relationship between seismic attenuation and CO 2 saturation. The relationship enables more reliable quantitative monitoring, because seismic attenuation becomes available for estimating amount of CO 2 in addition to seismic velocity. We introduce theoretical relationship which is built with patchy saturation model and standard linear solid model. In order to validate the models and the methodology, we compare the predicted attenuation with an experimental dataset. The result shows good agreement; therefore the methodology is considered to be appropriate to establish the relationship between seismic attenuation and CO 2 saturation.

Spatiotemporal changes of seismic attenuation caused by injected CO2 at the Frio‐II pilot site, Dayton, TX, USA

“…In contrast, seismic attenuation is observed to be at a maximum at partial saturation [ Winkler and Nur , ; Nakagawa et al ., ] and is still sensitive to large gas saturations 30–50% [ Carcione et al ., ; Lei and Xue , ; Azuma et al ., ; Caspari et al ., ]. Few field studies have attempted to utilize Q to assist in CO 2 saturation estimates due to the challenges of reliable estimation from conventional seismic monitoring data sets.…”