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Migration-based Deconvolution for High Resolution Locating of Microseismic Sources from Multi-Component Recordings
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 4th EAGE Passive Seismic Workshop, Mar 2013, cp-337-00033
- ISBN: 978-94-6282-040-1
Abstract
We describe and illustrate a locating method based on full-waveform 3D migration of three-component data to reconstruct components of the elastic wave field at any point in 3D space. To be a viable micro-earthquake source at a location, the compressional (P) and shear (S) wave fields reconstructed at this location should have similar wave shapes and be simultaneous. These two conditions are assured by an imaging condition based on inverse-energy-weighted correlation between the reconstructed P and S signals. This weighted correlation process is the least-squares solution to the problem of maximizing the zero-phase bandwidth of the common signal while minimizing the noise. The process measures, at optimal resolution, both the similarity and the synchronicity of the two signals, while the adaptation to the signal and noise conditions of the data ensures numerical stability. The process does not require an absolute timing of the data as the floating time reference common to the reconstructed P and S signals is eliminated by the correlation process. Without explicit phase picking and event association, the new method is well suited for automated data processing, and is equally applicable to the analysis of three-component data, acquired either in boreholes or on the surface.