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ADMM-based full-waveform inversion for microseismic imaging

Authors :
Ali Gholami
Hossein S. Aghamiry
Stéphane Operto
Alison Malcolm
Géoazur (GEOAZUR 7329)
Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur
COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])
Institute of Geophysics, University of Tehran
University of Tehran
Source :
Geophysical Journal International, Geophysical Journal International, 2022, 228 (1), pp.259-274. ⟨10.1093/gji/ggab332⟩, Geophysical Journal International, Oxford University Press (OUP), 2022, 228 (1), pp.259-274. ⟨10.1093/gji/ggab332⟩
Publication Year :
2021

Abstract

SUMMARYFull waveform inversion (FWI) is beginning to be used to characterize weak seismic events at different scales, an example of which is microseismic event (MSE) characterization. However, FWI with unknown sources is a severely underdetermined optimization problem, and hence requires strong prior information about the sources and/or the velocity model. The frequency-domain wavefield reconstruction inversion (WRI) method has shown promising results to mitigate the non-linearity of the FWI objective function generated by cycle-skipping. WRI relies on the reconstruction of data-assimilated wavefields, which approach the true wavefields near the receivers, a helpful feature when the source is added as an additional optimization variable. We present an adaptation of a recently proposed version of WRI based on the alternating direction method of multipliers that first finds the location of the MSEs and then reconstructs the wavefields and the source signatures jointly. Finally, the subsurface model is updated to focus the MSEs at their true locations. The method does not require prior knowledge of the number of MSEs. The inversion is stabilized by sparsifying regularizations separately tailored to the source location and velocity model subproblems. The method is tested on the Marmousi model using one MSE and two clusters of MSEs with two different initial velocity models, an accurate one and a rough one, as well as with added noise. In all cases, the method accurately locates the MSEs and recovers their source signatures.

Details

Language :
English
ISSN :
0956540X and 1365246X
Database :
OpenAIRE
Journal :
Geophysical Journal International, Geophysical Journal International, 2022, 228 (1), pp.259-274. ⟨10.1093/gji/ggab332⟩, Geophysical Journal International, Oxford University Press (OUP), 2022, 228 (1), pp.259-274. ⟨10.1093/gji/ggab332⟩
Accession number :
edsair.doi.dedup.....e055a7d99a1c5a6fd090dd7edac16af4
Full Text :
https://doi.org/10.1093/gji/ggab332⟩