In this work we present an eikonal equation–based approach to wave velocity tomography inside a micro–seismic event cloud. For this approach we consider the receiver as a source and all micro–seismic events as receivers. The difference of the events’ origin times and their P– and S–phase arrival times at the receiver provide the base to construct a travel time field from which we derive the underlying wave velocity field.
Under perfect conditions this approach is tested in a synthetic model setup, performing very good in reproducing the initial wave velocity model.
Furthermore, this approach is applied to the micro–seismic event cloud of the enhanced geothermal site in Basel, Switzerland. The results include not only the reconstruction of the P– and S–wave velocity fields, but also a comparison with borehole data and a look at the temporal evolution of the P– and S–wave velocities close to the injection point. We also successfully relocate the events within the new wave velocity model.
Presentation Date: Tuesday, October 18, 2016
Start Time: 8:00:00 AM
Location: Lobby D/C
Presentation Type: POSTER