In the 'explorer' project, we will develop methods for automatically capturing and labelling video data in "open worlds". The ultimate goal is the great facilitation of the creation and maintenance of Digital Twins: Digital Twins are virtual 3D copies of complex scenes such as cities, factories, or construction sites. Not just a 3D reconstruction, they should capture the scene's semantics, i.e. the identity of each object and the scene's dynamics, i.e. how objects move. Because Digital Twins have the potential to be extremely useful for monitoring large complex sites and planning the development of these sites, their forecast market is huge, they remain mostly a concept because of important limitations of the current technology. Our methods will guide autonomous systems such as robotic platforms and UAVs through complex and unknown environments to capture visual data for creating and maintaining Digital Twins. This is extremely challenging as these systems will encounter objects without any prior knowledge about them and will have to collect sufficient data about them. To the best of our knowledge, this active and automatic capture in complex real environments is a new problem. It is however very important to solve it as this will relax the need for human expertise and time: Currently, capturing such data is done manually only by researchers and requires strong understanding of what the learning algorithms require. To tackle the complexity of this problem, our approach is inspired by techniques from Artificial Intelligence applied to the exploration of extremely large trees. This approach will allow us to bring the perception part and the planning part of the problem together under the same optimization framework, to formalize it and solve it efficiently. To evaluate our developments, we will create a dataset of annotated video sequences from working sites, which we will share with the community.

Carbon Capture and Storage (CCS) is a solution to mitigate emissions from large-scale fossil energy and industrial sources. However, widespread implementation hinges on overcoming significant challenges. The global landscape of CCS has experienced notable growth in the past five years, driven by private sector response to public demands for a transition to a net-zero emissions future, as well as shifts in government policies and increased investments worldwide. For many regions, particularly in Europe, offshore storage emerges as the preferred choice, with transportation by ship offering compelling advantages, including reduced capital expenditure, lower financial risk, and heightened flexibility. A critical aspect of ship-based CO2 transport is the extremely low temperature required (-53°C at 7 bar) to maintain it in a liquid state. Injecting such a cold fluid into a reservoir with temperatures typically between 70°C and 200°C raises serious challenges, particularly for ensuring the well integrity, notably its main sealing element—the cement sheath. Identified risks include casing debonding, thermal fracturing, and the potential formation of CO2 hydrates and ice within the reservoir rock, cement, or caprock. The current project is dedicated to advancing the understanding and conducting a quantitative analysis of wellbore integrity during cold CO2 injection into a high-temperature reservoir. A multidisciplinary and multi-scale research program covering various methods and tools has been established. These range from thermodynamics and molecular dynamics simulations addressing CO2 hydrate formation to laboratory experiments characterizing casing/cement/rock interfaces, along with developing a laboratory-scale physical model of the well structure and numerical simulations at the wellbore scale.

Clays are nanostructured materials that contain adsorbed water, i.e., water molecules interacting with the solid skeleton. Clay hydration and dehydration is well known to induce important deformations of the material that may end up to instabilities such as desiccation cracking of soils in dry conditions. Cracking of clay-rich rocks can be detrimental (nuclear waste or CO2 storage) or beneficial (oil and gas recovery). Clay desiccation can originate from heating since an increment of temperature induces dehydration and shrinkage. Thermal stimulation is considered as a potential alternative to hydraulic fracturing for shale oil and gas recovery from clay-rich deposits. But the technique is exploratory and its feasibility has to be demonstrated. In this project, we will investigate in detail the physics of thermal expansion of adsorbing microporous media, in particular that of clays, and ultimately assess the feasibility of thermal stimulation of shales. Adsorption in microporous solids is known to induce unusual deformations that can be understood at the molecular scale and captured by thermodynamic integration. Adsorption can induce both shrinkage and swelling depending on the molecular interactions between the fluid and the solid. Accordingly the thermal expansion of adsorbing media can be complex and we propose in this project to study it from the molecular scale to get insight into the physical mechanisms involved. We will investigate various model situations by molecular simulation and derive analytical description of the phenomena from thermodynamics. We will pay a special attention to the physical mechanisms that are relevant for clays. Clays are complex multi-scale materials in which the nanostructure is made of planar micropores where adsorption is structured in layers and induces a swelling orthogonal to the layers, with sharp transitions in function of water chemical potential and temperature. In contrast, macroscopic experiments on clays show continuous thermal deformation with both contraction and expansion, depending on the pre-consolidation state of the material and on the temperature. In this project, we will investigate the thermal expansion of clays from the molecular scale to the macroscopic scale and bridge the gap between the two scales. A fine understanding of the behavior of clay will enable to develop a thermo-hydro-mechanical constitutive modeling with a good predictive ability over a wide range of temperatures and in-situ stresses, relevant for application to thermal stimulation of shales. Finally, this constitutive modeling will serve as a basis for a stability analysis of shale reservoirs and thus to determine the conditions favorable to desiccation cracking. This project is structured as a comprehensive multi-scale approach that involves molecular simulation, thermodynamics and statistical physics, mechanical homogenization and rock mechanics. This project will provide interesting scientific results for the understanding of microporous solids in general and of clays in particular. The project will also have a relevant impact for applications in emerging geotechnical issues involving clays, especially for shale oil and gas recovery.