Monitoring of seismic changes inside the reservoir layer during CO2 sequestration can be valuable for extraction of reservoir quantities like saturation and pore pressure. The accuracy of the monitoring could be deteriorated due to nonrepeatability errors in the source and receiver geometry. Applying seismic interferometry (SI) to permanent networks of seismic stations to retrieve virtual sources at the positions of the stations eliminates the non-repeatability in the source positioning. SI is traditionally applied using crosscorrelation. We show results from application of SI to ultrasonic data for layer-specific monitoring of sequestration of supercritical CO2. The data are recorded on a two-layer sample consisting epoxy (caprock) and Bentheimer sandstone (reservoir). We apply SI by crosscoherence, which has the potential to retrieve results with higher temporal resolution that SI by crosscorrelation. Using SI, we retrieve non-physical reflections from the bottom of the sandstone as if source and receiver were placed at the top of the sandstone. The velocities we estimate from the non-physical reflections during injection of brine aiming to displace supercritical CO2 and during injection of supercritical CO2 aiming to displace brine indicate rather similar saturation for both injection cases. We confirm the latter by transmission measurements, but with lower resolution.
Original languageEnglish
Title of host publicationSEG Technical Program Expanded Abstracts 2016
EditorsCharles Sicking, John Ferguson
PublisherSEG
Pages5516-5520
Number of pages5
DOIs
Publication statusPublished - 2016
EventSEG International Exposition and 86th Annual Meeting - Dallas & Kay Bailey Hutchison Convention Center, Dallas, United States
Duration: 16 Oct 201621 Oct 2016
Conference number: 86
http://seg.org/Events/Annual-Meeting

Publication series

NameSEG Technical Program Expanded Abstracts
PublisherSEG
Volume2016
ISSN (Electronic)1949-4645

Conference

ConferenceSEG International Exposition and 86th Annual Meeting
Abbreviated titleSEG 2016
CountryUnited States
CityDallas
Period16/10/1621/10/16
Internet address

    Research areas

  • monitoring, ultrasonic, reflection, time-lapse, correlation

ID: 6655893