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An Efficient Solution Against Chimney Artifacts in Rfwi Induced by Depth-Velocity Coupling at Narrow Aperture
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 83rd EAGE Annual Conference & Exhibition, Jun 2022, Volume 2022, p.1 - 5
Abstract
Reflection Full Waveform Inversion is the band-limited transcription of horizon-based traveltime tomography. The problems of the velocity update and of the depth repositioning of the reflectors in the newly updated model are coupled, which causes slow convergence in tomographic approaches. To cope with it, Audebert et al. (2020) proposed a booster preconditioner applied on the residuals of RFWI to amplify the data within narrow aperture, which reduces the number of iterations but does not prevent the development of chimney artifacts in the velocity update. In this paper, as a complement to the booster preconditioner, we propose a stabiliser preconditioner in function of the maximum aperture, inspired by Zhou et al. (2020) who derived the reachable resolution in the quantification of the velocity update to the maximum aperture, in the framework of Migration Velocity Analysis. In both methods, we show that, when the available average aperture angle is small enough, there is wall of uncertainty, which is an important factor in the development of chimney artifacts. Our stabiliser preconditioner corresponds to the inverse of this uncertainty. We observe in the Marmousi example that this stabiliser preconditioner is efficient at inhibiting the development of the chimney artifacts.