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Localization of seismic events in 3D media by diffraction stacking
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, Third EAGE Passive Seismic Workshop - Actively Passive 2011, Mar 2011, cp-225-00003
- ISBN: 978-90-73834-05-7
Abstract
The localization of seismic events is of great importance not only in seismology but also in exploration geophysics for monitoring of for instance hydraulic fracturing. It can be successfully implemented by diffraction stacking, where the source location is obtained from the maximum of the image function. Since the maximum of the image function is distinct, even very weak events can be detected. Previous research showed that the method works perfectly for homogeneous 2D media; we demonstrate the extension to 3D. Numerical examples in both homogeneous and heterogeneous media are presented. Strongly heterogeneous media are intensely affected by triplications. Localization of such events can be proceeded by taking the most energetic events into account. Moreover, by using geometrical spreading as weighting factors for the input data, separation of the propagation and source effects is achieved. Also effects of the double couple radiation pattern were investigated. Furthermore, the method was tested on field data from Southern California. Before applying diffraction stacking it was accounted for the acquisition footprint. The localization results deviate from the source position obtained by a standard picking method less than 1 km in all three directions. Both numerical and field data applications reveal the potential of the method.