The H-Cube Project: Hydrodynamics, Heterogeneity and Homogenization in CO2 storage modeling

The main goal of the project H-CUBE is to provide appropriate theoretical and numerical models for accurate evaluation of the hydrodynamic behavior of a CO2 storage complex and surrounding area. Particular emphasis will be placed on the determination of the CO2- brine flow with buoyancy forces and dissolution effect in saline aquifers with a methodology for assessing heterogeneity of the geological formations at several scales. This will consist in performing deeper studies on the impact of heterogeneities onto CO2 flow behaviors from near well injection zone (meter scale) to basin scale (~100km), in developing new techniques for optimizing the flow behavior simulation (up-scaling and homogenization techniques) and characterization (proposal of appropriate reservoir descriptors), and in proposing suitable modeling and statistical workflows for assessing uncertainty analysis in function of the envisaged geological contexts. The project is decomposed in four main work packages

CO2 leakage up from a geological storage site to shallow fresh groundwater: CO2-water-rock interaction assessment and development of sensitive monitoring

International audienceThe assessment of environmental impacts of carbon dioxide storage in geological repository requires the investigation of the potential CO2 leakage back into fresh groundwater, particularly with respect to protected groundwater reserves. We are starting a new project whith the aims of developing sensitive monitoring techniques in order to detect potential CO2 leaks and their magnitude as well as their geochemical impacts on the groundwater. In a predictive approach goal, a modelling study of the geochemical impact on fresh groundwaters of a CO2 intrusion during geological storage was performed and serves as a basis for the development of sensitive monitoring techniques (e.g. isotope tracing). Then, isotopic monitoring opportunities will be explored. A modeling study of the geochemical impact on fresh groundwaters of the ingress of CO2 during geological storage was conducted. The 3D model includes (i) storage saline aquifer, (ii) impacted overlying aquifer containing freshwater and (iii) a leakage path way up through an abandoned well represented as 1D porous medium and corresponding to the cement-rock formation interface. This model was used to simulate the supercritical CO2 migration path and the interaction between the fluid and the host rock

Enabling onshore CO2 storage in Europe: fostering international cooperation around pilot and test sites

To meet the ambitious EC target of an 80% reduction in greenhouse gas emissions by 2050, CO2 Capture and Storage (CCS) needs to move rapidly towards full scale implementation with geological storage solutions both on and offshore. Onshore storage offers increased flexibility and reduced infrastructure and monitoring costs. Enabling onshore storage will support management of decarbonisation strategies at territory level while enhancing security of energy supply and local economic activities, and securing jobs across Europe. However, successful onshore storage also requires overcoming some unique technical and societal challenges. ENOS will provide crucial advances to help foster onshore CO2 storage across Europe through: 1. Developing, testing and demonstrating in the field, under "real-life conditions", key technologies specifically adapted to onshore storage. 2. Contributing to the creation of a favourable environment for onshore storage across Europe. The ENOS site portfolio will provide a great opportunity for demonstration of technologies for safe and environmentally sound storage at relevant scale. Best practices will be developed using experience gained from the field experiments with the participation of local stakeholders and the lay public. This will produce improved integrated research outcomes and increase stakeholder understanding and confidence in CO2 storage. In this improved framework, ENOS will catalyse new onshore pilot and demonstration projects in new locations and geological settings across Europe, taking into account the site-specific and local socio-economic context. By developing technologies from TRL4/5 to TRL6 across the storage lifecycle, feeding the resultant knowledge and experience into training and education and cooperating at the pan-European and global level, ENOS will have a decisive impact on innovation and build the confidence needed for enabling onshore CO2 storage in Europe. ENOS is initiating strong international collaboration between European researchers and their counterparts from the USA, Canada, South Korea, Australia and South Africa for sharing experience worldwide based on real-life onshore pilots and field experiments. Fostering experience-sharing and research alignment between existing sites is key to maximise the investment made at individual sites and to support the efficient large scale deployment of CCS. ENOS is striving to promote collaboration between sites in the world through a programme of site twinning, focus groups centered around operative issues and the creation of a leakage simulation alliance

Effect of Geological Heterogeneities on Reservoir Storage Capacity and migration of CO 2 Plume in a Deep Saline Fractured Carbonate Aquifer

In a reservoir characterization study of the Hontomín deep saline aquifer, the impact of geological heterogeneities on reservoir storage capacity and the migration of the CO2 plume is explored. This work presents, for the first time, very long-term (up to 200 years) simulations of CO2 injection into the naturally fractured Sopeña Formation, of the lower Jurassic age, at Hontomín. CO2 injection was simulated as a dual permeability case with Eclipse compositional software. The matrix permeability of the carbonate reservoir is quite low (0.5 mD) and thus fluid flow through the fractures dominates. The reservoir is dissected by eight normal faults which limited its southeast extension and divided it into several segments. The effect of geological heterogeneities was tested through scenario-based modeling and variation of parameters characterizing heterogeneity within realistic limits based on other similar formations. This modeling approach worked well in Hontomín where the database is completely scarce. The plume migration, the reservoir storage capacity, and pressure, were each influenced in diverse ways by incorporating particular types of heterogeneities. The effect of matrix heterogeneities on reservoir storage capacity was substantial (by factors up to ~2.8×), compared to the plume migration. As the reservoir matrix permeability heterogeneity increased, the reservoir storage capacity markedly decreased, whilst an increase in porosity heterogeneity significantly increased it. The vertical gas migration in the homogeneous base case was relatively larger compared to the heterogeneous cases, and gas accumulated underneath the caprock via hydrodynamic trapping. It was also observed that, in heterogeneous cases, gas saturation in rock layers from top to bottom was relatively high compared to the base case, for which most of the gas was stored in the topmost layer. In contrast, the impact on storage capacity and plume movement of matrix vertical to horizontal permeability ratio in the fractured carbonate reservoir was small. The impact of the transmissibility of faults on reservoir pressure was only observed when the CO2 plume reached their vicinity

Caractérisation microsismique des massifs rocheux fracturés : modélisation thermo-hydraulique : application au concept géothermique de Soultz

Non disponible / Not availableLe site HDR de Soultz-sous-Forêts se présente sous la forme d'un doublet géothermique (un puits d'injection et un puits de production), hydrauliquement connecté par un réseau de fractures situé à plus de 3500 m de profondeur. La température en fond de puits a été mesurée à 162 °C environ à 3800 m de profondeur. Les objectifs d'un tel projet sont de récupérer la chaleur contenue dans le massif rocheux fracturé en établissant une circulation forcée de fluide entre les puits. Au passage dans le réseau de fractures, le fluide est réchauffé, et cette énergie calorifique est récupérée en surface pour être transformée, à l'aide d'une turbine, en électricité. Afin d'augmenter la perméabilité du réservoir et d'améliorer la connexion entre les puits, des essais de fracturation hydraulique ont été menés sur chacun des forages. Ces injections de fluide à forte pression (plusieurs dizaines de MPa), induisent une activité sismique de faible magnitude (inférieure à 4), appelée "microsismicité". Dans cette étude, l'utilisation des micro-événements permet de développer deux thématiques distinctes: - Le développement d'une méthode permettant d'inverser les données microsismiques en terme de perméabilité équivalente de la zone stimulée. Durant l'injection de fluide, la surpression engendrée dans le milieu se propage dans l'espace à une certaine vitesse. La célérité de cette onde est quantifiée en interprétant la répartition dans le temps et dans l'espace des micro-événements. En appliquant les lois de la poroélasticité, une perméabilité du milieu poreux équivalent au volume de roche fracturé est estimée. De cette estimation selon la direction de l'espace, un tenseur de perméabilité est défini. Cette méthode a été appliquée sur deux autres sites géothermiques, Fenton Hill aux USA et Ogachi au Japon. - La construction d'un modèle 3D capable de simuler les écoulements de fluide dans le massif ainsi que de quantifier les échanges de chaleur associés. Ce modèle intègre un maximum d'informations de différentes natures, observées et mesurées dans les puits: débit et pression, pendage et azimut des fractures, températures.. . Une fois le modèle hydraulique obtenu, le champ de vitesses de Darcy associé est utilisé pour la simulation numérique du refroidissement du volume de roche initialement chaud (échangeur géothermique), paramètre conditionnant la durée de "vie" de l'échangeur géothermique. Une estimation des courbes de refroidissement du futur échangeur prévu à 5000 m est également proposée. Ces paramètres techniques sont importants pour la détermination de la rentabilité économique d'un tel projet

Modeling geochemical reactions in wellbore cement: assessing preinjection integrity in a site for CO2 geological storage

International audienceWe present numerical simulations of isothermal reactive flow which might be induced by fluid migration at the caprock-cement interface of an idealized abandoned well in an area considered for geological sequestration of CO2 in the Paris Basin, France. The calculations are aimed at identifying the mineralogical transformations likely occurring in the cement during the working life and after the closure of the wells present in the area, before the injection of CO2. Field evidence, experimental data, and previous numerical simulations have been used to constrain the initial geochemical conditions and the hydraulic parameters of the model. Significant mineralogical transformations in the cement (portlandite and katoite dissolution, CSH, ettringite, hydrotalcite precipitation), and minor modifications of the initial clayrock mineralogical assemblage (quartz, montmorillonite and illite dissolution, and precipitation of cement-like phases) are predicted at the caprock-cement interface. Associated with these mineralogical transformations, measurable variations in porosity are also computed. Although Portland cement is predicted to retain its integrity at some distance from the interface, calculations confirm the general view that material alteration at the interfaces is of major concern for the minimization of the risks of CO2 leakage from storage zones. Numerical outputs are sensitive with respect to poorly constrained physical and transport parameters, such as the spatial distribution of interconnected porosity in the cement. Different degrees of portlandite dissolution/carbonate precipitation can be predicted during in situ ageing under conditions similar to the Paris Basin, depending on the adopted gridding scheme, i.e. on the conceptualization of the cement as a homogeneous or dual-porosity medium

Caractérisation microsismique des massifs rocheux fracturés (modélisation thermo-hydraulique)

Le site HDR de Soultz-sous-Forêts se présente sous la forme d'un doublet géothermique (un puits d'injection et un puits de production), hydrauliquement connecté par un réseau de fractures situé à plus de 3500 m de profondeur. La température en fond de puits a été mesurée à 162 C environ à 3800 m de profondeur. Les objectifs d'un tel projet sont de récupérer la chaleur contenue dans le massif rocheux fracturé en établissant une circulation forcée de fluide entre les puits. Au passage dans le réseau de fractures, le fluide est réchauffé, et cette énergie calorifique est récupérée en surface pour être transformée, à l'aide d'une turbine, en électricité. Afin d'augmenter la perméabilité du réservoir et d'améliorer la connexion entre les puits, des essais de fracturation hydraulique ont été menés sur chacun des forages. Ces injections de fluide à forte pression (plusieurs dizaines de MPa), induisent une activité sismique de faible magnitude (inférieure à 4), appelée "microsismicité". Dans cette étude, l'utilisation des micro-événements permet de développer deux thématiques distinctes: - Le développement d'une méthode permettant d'inverser les données microsismiques en terme de perméabilité équivalente de la zone stimulée. Durant l'injection de fluide, la surpression engendrée dans le milieu se propage dans l'espace à une certaine vitesse. La célérité de cette onde est quantifiée en interprétant la répartition dans le temps et dans l'espace des micro-événements. En appliquant les lois de la poroélasticité, une perméabilité du milieu poreux équivalent au volume de roche fracturé est estimée. De cette estimation selon la direction de l'espace, un tenseur de perméabilité est défini. Cette méthode a été appliquée sur deux autres sites géothermiques, Fenton Hill aux USA et Ogachi au Japon. - La construction d'un modèle 3D capable de simuler les écoulements de fluide dans le massif ainsi que de quantifier les échanges de chaleur associés. Ce modèle intègre un maximum d'informations de différentes natures, observées et mesurées dans les puits: débit et pression, pendage et azimut des fractures, températures.. . Une fois le modèle hydraulique obtenu, le champ de vitesses de Darcy associé est utilisé pour la simulation numérique du refroidissement du volume de roche initialement chaud (échangeur géothermique), paramètre conditionnant la durée de "vie" de l'échangeur géothermique. Une estimation des courbes de refroidissement du futur échangeur prévu à 5000 m est également proposée. Ces paramètres techniques sont importants pour la détermination de la rentabilité économique d'un tel projet.RENNES-Géosciences (352382209) / SudocNANCY/VANDOEUVRE-INPL (545472102) / SudocSudocFranceF

Impacts of fluvial sedimentary heterogeneities on CO2 storage performance

Session H24B. Heterogeneity and Geologic Storage of CO2 IIThe heterogeneity of fluvial systems is a key parameter in sedimentology due to the associated impacts on flow performance. In a broader context, fluvial reservoirs are now targets for CO2 storage projects in several sedimentary basins (Paris Basin, North German Basin), thus calling for detailed characterization of reservoir behaviour and capacity. Fluvial reservoirs are a complex layout of highly heterogeneous sedimentary bodies with varying connectivity, depending on the sedimentary history of the system. Reservoir characterization must determine (a) the nature and dimension of the sedimentary bodies, and (b) the connectivity drivers and their evolution throughout the stratigraphic succession. Based on reservoir characterization, geological modelling must account for this information and can be used as a predictive tool for capacity estimation. Flow simulation, however, describes the reservoir behaviour with respect to CO2 injection. The present work focuses on fluvial reservoir performance and was carried out as part of a PhD (2008-2011) dedicated to the impact of sedimentary heterogeneity on CO2 storage performance. The work comprises three steps: ● Reservoir characterization based on detailed fieldwork (sedimentology and sequence stratigraphy) carried out in Central Arabia on the Minjur Sandstone. Twelve depositional environments and their associated heterogeneity are identified, and their layout is presented in a high-resolution sequence stratigraphy analysis. This step is summed up in a 3D geological model. ● Conceptual modelling based on this field data, using gOcad software and an in-house python code. The purpose was to study, for a given architecture, the impact of sedimentary heterogeneity on storage capacity estimations using two models: one with heterogeneity within the sedimentary fill (model A); the other without heterogeneity within the sedimentary fill (model B). A workflow was designed to estimate and compare the storage capacities for a series of some 50 scenarios. The results show that a strong compartmentalization, due to a shaly barrier, may decrease storage capacity by 11 to 25 percent. ● Flow-simulation of an 8-scenario sample extracted from the 50 possible scenarios. In contrast to the static modelling estimated capacities, the preliminary flow-simulation results indicate that capacity remains similar whichever model is applied (A or B). This is because the scale of the heterogeneity is similar to the extent of the CO2 plume, meaning that heterogeneity does not affect the amount of injected CO2 that can be stored in the sedimentary body. Nevertheless, connectivity strongly influences storage capacity, as determined by the 8 scenarios (model A) in which the total amount of CO2 injected ranges between 7 and 12 Mt over a 50-year period. Moreover, heterogeneity significantly increases pressure build-up, and may strongly disrupt the hydrodynamics in the aquifer

Evaluation of Hydrogen migration and geochemical reactivity into underground

International audienceThe use of hydrogen as an alternative for energy storage has emerged rather recently though it was originally more identified as a secondary energy carrier and storage medium. By way of electrolysis it becomes one of the major actors in the possible conversion of excess wind or solar energy with the favorable arguments of being environment-friendliness and having high storage densities [1]. The concept of "Power to Gas" comes from the conversion of electricity into gas via electrolysis process. Hydrogen and Oxygen produced under various forms can be reused for several purposes and applications. Research project related to investigate the feasibility of storing hydrogen in porous geological formations are under development like the H2STORE project in Germany [2], the European project HyUnder which proposes to evaluate thoroughly from a technical, economic and societal standpoint if hydrogen underground storage can become a potentially attractive solution [3]. In Austria, the Undergound SUN.STORAGE project, led by the Rohöl-Aufsuchungs Aktiengesellschaft (RAG), conduct research and analysis of the impact of hydrogen on underground gas (methane) storage systems [4]. In Pentagonia, Argentina, Hychico S.A. is conducting operations to convert electricity produced from the Diadema wind farm into hydrogen to be injected into a depleted oil field converted into a methane gas storage reservoir [5]. In this paper we assess the transport properties of hydrogen gas injected into a sandstone formation like. Using a core sample of the rock, laboratory experiment is conducted to evaluate the permeability relative to hydrogen gas phase flow into a water saturated sample of sandstone rock representative of the Alsace Triassic formation. Geochemical reactivity of dissolved hydrogen with clay minerals of the rock is also investigated using autoclave experiments, meaning that crushed powder of rock is remained in contact with hydrogen and water for several weeks to evaluate the possible change of the chemical composition of the water in contact with Hydrogen and rock mineralogy. These measurements should serve at providing reservoir storage criteria for estimation with numerical modeling tools of storage capacity of underground sedimentary formation for large scale storage of hydrogen. REFERENCES 1. Crotogino, F., Donadei, S., Bünger, U., Landinger, H., Large-scale hydrogen underground storage for securing future energy supplies, Detlef Stotlen, Thomas Grube (Eds.)