Thèse Sparse Seismic Monitoring Beyond Reflected Waves H/F - Doctorat.Gouv.Fr

Établissement : Mines Paris-PSL École doctorale : Géosciences, Ressources Naturelles et Environnement Laboratoire de recherche : Centre de Géosciences Direction de la thèse : Hervé CHAURIS ORCID 0000000166520381 Début de la thèse : 2026-10-01 Date limite de candidature : 2026-09-30T23:59:59 . Seismic imaging offers a unique way of finely characterising the subsurface by sending waves from the surface. In the context of CO2 injection and storage, the
subsurface properties vary over time. It is therefore essential to repeat the acquisition and to analyse any modifications. However, 4D dense acquisitions (repeated 3D
imaging over time) are not affordable for economic reasons. Based on an initial 3D image, SpotLight Earth has developed a strategy for deploying a few sources and receivers at optimal locations to detect the evolution of the CO2 plume within the subsurface. This makes it possible to repeat the acquisition monthly, for example, rather than every two years for the standard approach. This is an important factor for controlling the integrity of the reservoir and for preventing any CO2 leakage towards the surface.
Currently, the analysis of such sparse acquisition data sets is based on reflected waves only, i.e. waves propagating from the source to some elastic contrast, being
reflected at some elastic contrasts only once, and reaching the surface. However, real wave propagation is much more complex. We can potentially consider
diffractions, refractions, diving waves, maybe surface waves, ... as far as these waves are influenced by the modifications of the subsurface. Currently, these other
waves are simply ignored.

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• Monitoring