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TitleAssessment of 4D seismic repeatability and CO2 detection limits using a sparse permanent land array at the Aquistore CO2 storage site
AuthorRoach, L A N; White, D J; Roberts, B
SourceGeophysics vol. 80, no. 2, 2015 p. WA1-WA13,
Alt SeriesEarth Sciences Sector, Contribution Series 20140197
PublisherSociety of Exploration Geophysicists
Mediaon-line; paper; digital
File formatpdf
AreaEstevan; Aquistore CO2 Storage Site
Lat/Long WENS-103.1000 -103.0333 49.1333 49.0333
Subjectsgeophysics; seismic surveys; analytical methods; modelling; carbon dioxide; gas storage
ProgramCarbon Capture & Storage, Environmental Geoscience
AbstractTwo 3D time-lapse seismic surveys were acquired in 2012 and 2013 at the Aquistore CO2 storage site prior to the start of CO2 injection. Using these surveys, we determined the background time-lapse noise at the site and assessed the feasibility of using a sparse areal permanent receiver array as a monitoring tool. Applying a standard processing sequence to these data, we adequately imaged the reservoir at 3150-3350 m depth. Evaluation of the impact of each processing step on the repeatability revealed a general monotonic increase in similarity between the data sets as a function of processing. The prestack processing sequence reduced the normalized root mean squared difference (nrms) from 1.13 between the raw stacks to 0.13 after poststack time migration. The postmigration cross-equalization sequence further reduced the global nrms to 0.07. A simulation of the changes in seismic response due to a range of CO2 injection scenarios suggested that CO2 was detectable within the reservoir at the Aquistore site provided that zones of greater thickness than 6-13 m have reached CO2 saturations of greater than 5%.
Summary(Plain Language Summary, not published)
This study (with the companion paper by White et al.) demonstrates the technical feasibility of using a sparse array of seismic sensors for monitoring CO2 storage sites. This has the potential to substantially reduce the cost of time-lapse seismic monitoring and thus help enable deployment of CCS technology.