Analysis of Microseismic Events from a Stimulation at Basel, Switzerland
- Key words
- Drilling; Microseismicity; HDR; HWR; Hfr; Stimulation; Basel
- Location
- Basel, Switzerland
- Conference
- Geothermal Resources Council Transactions
- Year
- 2007
- Session
- Drilling; Microseismicity; HDR/EGS; Reservoir modeling; Frac
- Language
- English
Abstract
The researchers from Tohoku University, Japan, analyzed microseismic events collected during a stimulation at Basel, Switzerland in December 2006. More than 2,000 events from over 13,000 triggers were located by the single event determination (SED) method, by joint hypocenter determination (JHD), and by the coherence-collapsing method (COH-COL). The located events define a seismic cloud with a sub-vertical structure and an azimuth of N159°E, which is similar to that at Soultz. The percentage of multiplets among the located events was 75%, which was higher than that at Soultz. The spatio-temporal analysis of the microseismic locations showed clear shut-in events around the stimulated zone and continuous seismic activity after pumping, suggesting that the stress state around the reservoir was nearly critical for shear slip.
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