A site selection methodology for CO2 underground storage in deep saline aquifers: case of the Paris Basin

International audienceSite selection is a fundamental step, which can condition the success of a CO2 geological storage. A CO2 storage has to gather several targets, which can be expressed through a list of criteria. In the proposed site selection methodology, these criteria can be classified into “killer criteria” and “site-qualification criteria”, whose combinations allow identifying potential sites and the most appropriate one(s). This multicriteria methodology is applied on the PICOREF study area, located in the Paris Basin, on which potential site(s) in deep saline aquifers are investigated

The geological-event reference system, a step towards geological data harmonization

The temporal dimension is an inherent component of geology. In this regard, traditional geological maps can represent a few geological events, yet they hardly account for the entire complex rock history whether sedimentary, crystalline or volcanic. Here, using the RGF research program (French Geological Reference platform) we propose a new methodology based on digital technology and the French historical collection of 1:50 000-scale geological maps. This innovative approach consists of describing, organizing and hierarchizing a series of geological events within a reference framework and linking it to GIS map geometries (polygons, faults, points). In this way, the complete history of geological features can be compiled and stored in digital maps, combining distinct geological events and properties. For a single event, all associated transformations can be represented on maps, facilitating the production of real “palaeo-geological” maps that consider not only traditional sedimentary environments but also possible synchronous weathering, metamorphism, and volcanism. We discuss here an example of French orogenic history. The approach demonstrated here on geological maps can be used with other geological data media (boreholes, seismic reflection profiles, etc.) and thus facilitate a 3D-to-4D scale, with a significant ability to address not only academic community needs, but also themes or issues related to applications required by politics, civil engineering, and society itself, to confront challenges such as natural and anthropic risk reduction and subsurface uses

Earth models for underground resource exploration and estimation

This chapter introduces a certain number of geological concepts that are reused in the rest of the book. It depicts the geological objects classically explored for underground resources exploitation (hydrocarbon, water, storage of energy or wastes) such as sedimentary basins, aquifers or reservoirs. Aim and use of geological modeling are presented. Some of the input data and some characteristics of geological models such as components and versioning are described

Building Ontologies for analyzing data expressed in natural language

This chapter deals with the issue of translating natural language representations so that their semantic content can be used by a software system. There exist indeed major differences between the informal representations formulated by geologists in natural language and the fully formalized ontology based representations that can be processed by automatic systems. Two methods for building ontologies from and for textual material exploitation are presented. The goal is the construction of data models or concept maps rather than fully formalized ontologies expressed in some ontology language. The first method is description-oriented. It intends to provide a methodology for constructing domain data models from short textual descriptions. It is focused on the multidisciplinary subject of rock description. The second method is document-oriented. It aims at allowing the construction of semi-formal representations such as hierarchies or concept and properties starting from long textual documents. Approaches which try to exploit grammatically structured sets of words possibly nested within full sentences are presented. This second method is instrumented through a collaborative ontology editor which integrates two tools for automatic analysis of natural language

Technical and economic feasibility of the capture and geological storage of CO2 from a biofuel distillery: CPER Artenay project

International audienc

Respective roles of the weathering profile and the tectonic fractures in the structure and functioning of crystalline thermo-mineral carbo-gaseous aquifers

International audienceCrystalline thermo-mineral and carbo-gaseous (CTMCG) hydrosystems are well known for their economic importance in fields such as thermal, spa activities and natural mineral water (NMW) bottling. Such systems are usually associated with strong structural complexity, which is rarely characterised in detail or robustly. This research focuses on a CTMCG hydrosystem associated with a peri-alpine graben. A multidisciplinary approach with a very large set of data and methods – geological modelling with geophysics and geological data from outcrops and several boreholes, hydrodynamic data, hydrochemistry, hydrogeological and geochemical modelling – reveals very novel results and allows a robust conceptual model to be constructed. The aquifer at the origin of the carbo-gaseous natural mineral water is the 100–125 m-thick fractured stratiform layer of the weathering profile of the crystalline rock (granite). It forms a rather large and thick inertial aquifer that can be numerically modelled, in a similar fashion to a porous medium. The majority of tectonic faults length act as impervious boundaries that divide this aquifer into around ten elongated compartments that were precisely delineated. These tectonic faults are permeable only along two small areas that were also precisely located. These permeable zones feed some aquifer compartments with deep, highly mineralised carbo-gaseous water, which mixes with “fresher” water and forms the exploited NMW. These results can be generalised and in particular show a strong opposition between low-inertia CTMCG hydrosystems without a subsurface reservoir, as the weathering profile was eroded, and high-inertia hydrosystems such as the one studied

The geological-event reference system, a step towards geological data harmonization

The temporal dimension is an inherent component of geology. In this regard, traditional geological maps can represent a few geological events, yet they hardly account for the entire complex rock history whether sedimentary, crystalline or volcanic. Here, using the RGF research program (French Geological Reference platform) we propose a new methodology based on digital technology and the French historical collection of 1:50 000-scale geological maps. This innovative approach consists of describing, organizing and hierarchizing a series of geological events within a reference framework and linking it to GIS map geometries (polygons, faults, points). In this way, the complete history of geological features can be compiled and stored in digital maps, combining distinct geological events and properties. For a single event, all associated transformations can be represented on maps, facilitating the production of real “palaeo-geological” maps that consider not only traditional sedimentary environments but also possible synchronous weathering, metamorphism, and volcanism. We discuss here an example of French orogenic history. The approach demonstrated here on geological maps can be used with other geological data media (boreholes, seismic reflection profiles, etc.) and thus facilitate a 3D-to-4D scale, with a significant ability to address not only academic community needs, but also themes or issues related to applications required by politics, civil engineering, and society itself, to confront challenges such as natural and anthropic risk reduction and subsurface uses

Evolution Crétacé supérieur- Tertiaire dubassin d’Aquitaine Résultats du projet Gaia

National audienceLe bassin d’Aquitaine constitue au cours du Crétacé supérieuret du Tertiaire le retroforeland de l’orogène pyrénéen. Si la dynamiquede la déformation et de la sédimentation du versantsud pyrénéen (proforeland) est bien connue du fait de la qualitéd’affleurement et des nombreuses études qui y ont été consacrées,l’évolution du bassin d’Aquitaine, à l’exception d’une remarquablesynthèse datant des années 1970 et de travaux plusrécents est restée relativement mal connue jusqu’à récemment.De nombreux efforts ont été réalisés ces dernières années pourcomprendre la dynamique de son évolution en lien avec l’orogènepyrénéen. Nous présenterons ici les principaux résultats du projetGaia dont l’objectif est de fournir une caractérisation et unmodèle d’écoulement des aquifères crétacés supérieur et tertiairesanté- molasse d’Aquitaine. Il se base en premier lieu sur une mise àniveau de la connaissance géologique du Bassin d’Aquitaine. Basésur la réinterprétation et la synthèse d’une base de données exceptionnelleconstituée en particulier par les profils sismiques, forageset datations biostratigraphiques issus de l’exploration pétrolière,ce projet permet d’actualiser la connaissance de l’évolution dubassin d’Aquitaine du Crétacé supérieur à l’Eocène supérieur. Lesprincipaux apports sont :- Une restitution de la distribution 3D des épaisseurs au cours desgrandes étapes de l’évolution du bassin. (intra-Crétacé supérieur,Paléocène, Yprésien, Lutétien- Bartonien) permettant de retracerl’évolution de la dynamique du bassin.- Une amélioration du calage temporel et du style de la déformationde l’avant pays.- Une restitution des géométries et de la dynamique sédimentairesau cours de ces étapes, en lien avec la déformation et l’arrivée desproduits d’érosion de la chaîne en cours d’édification.Couplé à l’enregistrement connu dans la chaine pyrénéenne etcompilée avec les données précédentes, cette synthèse permetune meilleure compréhension de la dynamique du retroforelanden réponse à l’évolution de l’orogène pyrénéen. En particulier,ces résultats permettent de contraindre les premières déformationscompressives d’âge Crétacé supérieur au début de laconvergence Ibérie-Eurasie, la dynamique du bassin durant lePaléocène, la réponse des systèmes sédimentaires et l’évolutiondu bassin flexural au cours de l’Eocène, le comblement progressifet l’enregistrement dans l’avant pays de la phase paroxysmale dela convergence Ibérie-Eurasie