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| Titel |
Passive Image Interferometry for the Monitoring of CO2 Injections |
| VerfasserIn |
R. Mündel, C. Sens-Schönfelder, M. Korn |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250023266
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| Zusammenfassung |
| In this paper we describe an experiment to test the feasibility to monitor the CO2
sequestration in Ketzin with Passive Image Interferometry (PII). This technique is based on
seismic noise from distant sources and allows to continuously monitor variations of the
seismic velocity with high precision. For this purpose we installed a temporary seismic
network of seven seismic stations in the injection area. The station network has an east-west
extent about 2.4 km and a north-south extent of about 4 km. Three seismometer are placed
on the injection site, one of them 20 m far away from the injection well and two more
about 200 m away. The start of the measurement was May 16 2008 well before the
beginning of the injection. To check the quality of the stations we looked for the micro
seismic peaks that we can observe with variable strength at all stations. A dominant
component in the signals is anthropogenic noise. However, over the night from
22 pm to 4 am and at weekends the data are relatively quiet. On the injection site
strong technical noise is generated by pumps and other equipment. Due to these
particular circumstances, the generation of Green’s function approximations by
cross-correlation requires some care to be taken. Without processing the raw data do not
show any correlations. However, with a 1-bit-normalization in time domain and
filtering with a bandpass filter between 1 and 5 Hz clear correlations can be observed
that are related to seismic phases travelling between the stations at a velocity of
about 330 m/s. Using more advanced preprocessing techniques in the time and
frequency domains we will extend the useful frequency range and start to compare
Green’s functions from different time periods to detect possible velocity changes. |
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