Operto S. auteur aut IRD Amestoy P. auteur aut IRD Aghamiry H. auteur aut IRD Beller S. auteur aut IRD Buttari A. auteur aut IRD Combe L. auteur aut IRD Dolean V. auteur aut IRD Gerest M. auteur aut IRD Guo G. auteur aut IRD Jolivet P. auteur aut IRD L'Excellent J.Y. auteur aut IRD Mamfoumbi F. auteur aut IRD Mary T. auteur aut IRD Puglisi C. auteur aut IRD Ribodetti Alessandra auteur aut IRD Tournier P.H. auteur aut IRD text journalArticle eng text/pdf born digital access Frequency-domain full-waveform inversion (FWI) is potentially amenable to efficient processing of full-azimuth long-offset stationary-recording seabed acquisition carried out with a sparse layout of ocean-bottom nodes (OBNs) and broadband sources because the inversion can be performed with a few discrete frequencies. However, computing the solution of the forward (boundary-value) problem efficiently in the frequency domain with linear algebra solvers remains a challenge for large computational domains involving tens to hundreds of millions of parameters. We illustrate the feasibility of 3D frequency-domain FWI with a subset of the 2015/2016 Gorgon OBN data set in the North West Shelf, Australia. We solve the forward problem with the massively parallel multifrontal direct solver MUMPS, which includes four key features to reach high computational efficiency: an efficient parallelism combining message-passing interface and multithreading, block low-rank compression, mixed-precision arithmetic, and efficient processing of sparse sources. The Gorgon subdata set involves 650 OBNs that are processed as reciprocal sources and 400,000 sources. Monoparameter FWI for vertical wavespeed is performed in the viscoacoustic vertically transverse isotropic approximation with a classical frequency continuation approach proceeding from a starting frequency of 1.7 Hz to a final frequency of 13 Hz. The target covers an area ranging from 260 km2 (frequency ? 8.5 Hz) to 705 km2 (frequency ? 8.5 Hz) for a maximum depth of 8 km. Compared to the starting model, FWI dramatically improves the reconstruction of the bounding faults of the Gorgon horst at reservoir depths as well as several intrahorst faults and several horizons of the Mungaroo Formation down to a depth of 7 km. Seismic modeling reveals a good kinematic agreement between recorded and simulated data, but amplitude mismatches between the recorded and simulated reflection from the reservoir suggest elastic effects. Therefore, future works involve multiparameter reconstruction for density and attenuation before considering elastic FWI from hydrophone and geophone data. specialized 066GPHGEN 066SISMO 020MATH 42 3 173-183 2023 1070-485X https://www.documentation.ird.fr/hor/fdi:010089131 10.1190/tle42030173.1 1070-485X [F B010089131] https://www.documentation.ird.fr/hor/fdi:010089131 https://www.documentation.ird.fr/intranet/publi/2024-01/010089131.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2024-01-08 2026-06-12 fdi:010089131 fre