GEOSCAN, résultats de la recherche


TitrePassive seismic reflection interferometry: a case study from the Aquistore CO2 storage site, Saskatchewan, Canada
AuteurCheraghi, S; White, D J; Draganov, D; Bellefleur, G; Craven, J A; Roberts, B
SourceGeophysics vol. 82, no. 3, 2017 p. B79-B93,
Séries alt.Secteur des sciences de la Terre, Contribution externe 20160347
ÉditeurSociety of Exploration Geophysicists
Documentpublication en série
Mediapapier; en ligne; numérique
Formatspdf; html
Lat/Long OENS-103.1000 -103.0333 49.1167 49.0667
Sujetsinterprétations géophysiques; interpretations sismiques; levés de reflexion sismiques; géologie du substratum rocheux; géophysique; stratigraphie; géologie structurale
Illustrationslocation maps; tables; seismic reflection profiles; spectra; graphs; diagrams; geophysical images; models; profiles
ProgrammeSaisi et entreposage de carbone, Géosciences environnementales
Résumé(disponible en anglais seulement)
Seismic reflection interferometry has recently been tested in a few resource-exploration applications. We have evaluated passive seismic interferometry results for data from the Aquistore CO2 storage site, Saskatchewan, Canada, with the objective of testing the method's ability to image the subsurface geology and its potential for time-lapse imaging. We analyzed passive seismic data recorded along two perpendicular geophone lines for two time periods that include 23 days in June 2014 and 13 days in February 2015. Beam-forming analysis showed that a nearby power plant is the dominant source of ambient noise. We retrieved virtual shot gathers not only by correlating long noise panels (1 h) for both recording periods, but also by correlating shorter noise panels (10 s) from two days of each recording period. We applied illumination diagnosis to the noise panels from the two chosen days for each period to help suppress the surface waves. Comparisons of the common-midpoints stacked sections, resulting from the virtual shot gathers, with colocated active-source images and log-based synthetic seismograms showed that the best ambient-noise images were obtained for the longest recording periods. The application of illumination diagnosis revealed that only a small percentage of the noise panels are dominated by body waves. Thus, images formed using only this subset of noise panels failed to improve the images obtained from the 23 and 13 days of noise recording. To evaluate the passive images, we performed log-based correlations that showed moderate correlation ranging from approximately 0.5-0.65 in the two-way time range of 0.8-1.5 s. For the 13 to 23 days of noise used in our analysis, the resulting images at the reservoir depth of 3200 m or ~1.85 s are unlikely to be suitable for time-lapse imaging at this site. This is most likely due to the limited directional illumination and dominance of surface-wave noise.
Résumé(Résumé en langage clair et simple, non publié et disponible en anglais seulement)
This research shows feasibility of passive seismic interferometry method to monitor a CO2 reservoir at depth of about 3 km. Passive seismic data was acquired in June 2014 and February 2015. Both datasets were processed to test capability of the method for imaging geological formations at depth of about 3 km. The validity of results is evaluated while they are compared to available active survey images in the area.