CIFRE PhD - Sparse seismic monitoring: beyond reflected waves

CIFRE PhD - Sparse seismic monitoring: beyond reflected waves

05/06/2026 Cifre

MINES ParisTech

CIFRE PhD - Sparse seismic monitoring: beyond reflected waves

Context

Seismic imaging offers a unique way to finely characterise 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, SpotLightEarth 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.

Main objectives

The main objectives of the project are

• Study the sensitivity of different types of waves to some elastic changes, both in terms of both kinematics (time delays) and dynamics (amplitude modifications);
• Propose a strategy to map the changes (recorded by the waves at the surface in the time domain) to some subsurface locations (i.e. construct partial images to locate the changes in depth);
• Assess uncertainties (Bayesian context) on the modifications of the subsurface images by considering different sources of uncertainties, while respecting a priori information;
• Design an optimal acquisition geometry to capture the changes and to discriminate between different scenarios; take into account operational constraints;
• Validate on real data sets;
• Play a central role in the collaboration between Mines Paris, SpotLightEarth and clients who provide the real data sets.

The PhD student will benefit from existing numerical modelling tools to investigate the potential of different types of waves for monitoring the subsurface. He/she will develop a specific imaging tool, considering sparse data and a specific datatype.

Contacts and Places of Work

Dr. Nour Mikhael

SpotLightEarth

The PhD will be jointly supervised by Mines Paris (academic partner and SpotLightEarth (industrial partner as part of a collaborative CIFRE project (co‑funded by ANRT Mines Paris has extensive experience in seismic modelling and in quantitative seismic imaging in various contexts, but also in uncertainty assessment. Meanwhile, SpotLightEarth is recognised for its expertise in CO2 monitoring within Carbon Capture and Storage projects.

France

MINES ParisTech

ED 398

The PhD student should have a strong background in mathematics, physics and signal processing, as well as good scientific programming capabilities. He/she should be interested in geophysics and more precisely in seismic modelling and imaging. He/she should be motivated by developing academic projects with an industrial impact.