Publication Date:
2016-12-29
Description:
The injection of CO 2 at the Ketzin pilot CO 2 storage site started in June 2008 and ended in August 2013. During the 62 months of injection, a total amount of about 67 kt of CO 2 was injected into a saline aquifer. A third repeat 3D seismic survey, serving as the first post-injection survey was acquired in 2015, aiming to investigate the recent movement of the injected CO 2 . Consistent with the previous two time-lapse surveys, a predominantly WNW migration of the gaseous CO 2 plume in the up-dip direction within the reservoir is inferred in this first post-injection survey. No systematic anomalies are detected through the reservoir overburden. The extent of the CO 2 plume west of the injection site is almost identical to that found in the 2012 second repeat survey (after injection of 61 kt), however there is a significant decrease in its size east of the injection site. Assessment of the CO 2 plume distribution suggests that the decrease in the size of the anomaly may be due to multiple factors, such as limited vertical resolution, CO 2 dissolution and CO 2 migration into thin layers, in addition to the effects of ambient noise. 4D seismic modelling based on dynamic flow simulations indicates that a dynamic balance between the newly injected CO 2 after the second repeat survey and the CO 2 migrating into thin layer and being dissolved was reached by the time of the first post-injection survey. Considering the considerable uncertainties in CO 2 mass estimation, both patchy and non-patchy saturation models for the Ketzin site were taken into consideration. This article is protected by copyright. All rights reserved
Print ISSN:
0016-8025
Electronic ISSN:
1365-2478
Topics:
Geosciences
,
Physics
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