Jeremy Rohmer - Academia.edu (original) (raw)

Papers by Jeremy Rohmer

Energy Procedia, 2011

This paper deals with the electrical resistivity monitoring of the Ketzin CO2 injection pilot (CO... more This paper deals with the electrical resistivity monitoring of the Ketzin CO2 injection pilot (CO2ReMoVe EC project) through time-lapse CSEM measurements. There, 3 boreholes about 800 m deep have been especially designed for current injection at reservoir (sandstone) depth. CO2 is directly injected in a saline (∼240 g/l) aquifer. Prior modelling results indicated that the increase of electrical resistivity generated by the

International Workshop on Geomechanics and Energy, 2013

ABSTRACT Even though reservoirs targeted for CO2 storage are expected to be located in low-deform... more ABSTRACT Even though reservoirs targeted for CO2 storage are expected to be located in low-deformed tectonic settings, they can still present reservoir-scale faulted structures. Such faulting at the medium sub-seismic scale can play a significant role regarding several risk issues related to the injection-induced fluid pressure increase (fluid compartmentalization, loss of integrity in reservoir–caprock systems potentially associated with triggered seismicity and generation of leakage pathways). Yet, the characterization of the hydro-mechanical behaviour of such reservoir-scale fault structures is still lacking mainly due to the necessary seismic resolution ranging from 1 to 10 m at the reservoir scale (i.e. the “sub-seismic region”). The objective of the present study is to gain a deeper understanding of the shear reactivation of such structures subjected to pore pressure increase induced outside the CO2 injection zone. The present study relies on the combination of geological outcrop surveys in a carbonate analogue for CO2 storage reservoir (southern France) and fully coupled hydro-mechanical finite-element two-dimensional simulations. A special attention was paid to the influence of the characteristics of two specific fault components: 1. damage zone geometry and 2. fault core architecture (curvature and number of curved branches).

Energy Procedia, 2014

A possible risk of geomechanical nature related to deep injection of CO 2 is the shear reactivati... more A possible risk of geomechanical nature related to deep injection of CO 2 is the shear reactivation of faults, hence potentially leading to the creation of new leakage pathways and eventually inducing earthquakes felt at the surface. Current practices to evaluate fault stability in the domain of CO 2 storage still remain limited regarding two issues: 1. Faults are complex and heterogeneous geological systems, which do not correspond to discrete surfaces as already postulated by many authors. Reservoir-scale faults in a priori low-deformed reservoirs targeted for CO 2 storage can present high complex architecture, which might influence the hydro-mechanical behaviour of the fault system; 2. Chemical interactions (dissolution and precipitation processes, chemically-induced weakening, etc.) between CO 2 -enriched brine and the minerals constituting the fault zone can affect the mechanical stability and the transport properties of the faulted/fractured system. The research project FISIC (www.anrfisic.fr, funded by the French National research Agency) intends to overcome those limitations by accurately modelling the hydro-chemo-mechanical complexity of a fault zone. The main goal is to improve the stability analysis of a fault both undertaking pressure increase and alteration due to the presence of an acidic fluid. The progress of this research project is presented here.

Greenhouse Gases: Science and Technology, 2014

Methodologies for quantitative risk assessment regarding CO 2 storage operations are currently 16... more Methodologies for quantitative risk assessment regarding CO 2 storage operations are currently 16 scarce mostly because of the lack of experience in this field and the relatively significant 17 uncertainty degree regarding the subsurface intrinsic properties and the processes occurring 18 after the injection starts. This paper presents a practical approach designed to perform a 19 quantitative risk assessment in an uncertain context. Our approach is illustratedon a realistic 20 case study (Paris basin, France), conceived to be representative of the level of information 21 available in the early stages of a project.It follows the risk assessment principles from the 22 international standard(ISO 31000:2009), whichare adapted to account for the specificities and 23 challenges of subsurface operations. After the establishment of the context of the specific case 24 study, the main risks were identified and we analysed two different risk scenarios(risk of brine 25 2 leakage from an abandoned well, riskof subsurface use conflict).These scenarios were 26 selected to give a comprehensive overview of different types of analysis in terms of available 27 data, modelling tools and uncertainty management methodologies.The main benefit of this 28 paper is to proposeanapproach, based on existing risk assessment standards, best practices and 29 analysis tools,which allows an objective quantitative risk analysis taking into account the 30 uncertainties, and therefore enablesa fully informed decision-making whileevaluating risk 31 acceptability. 32 33 3

Energy Procedia, 2014

ABSTRACT In the present study, we applied two strategies for improving the use of InSAR/PSI techn... more ABSTRACT In the present study, we applied two strategies for improving the use of InSAR/PSI techniques for long-term monitoring ground surface deformation induced by CO2 injection areas presenting a large cover of vegetation (agricultural fields, forests, etc.). The first approach relies on advanced processing techniques using the Diffuse-Scatterers-like (DS) technique. Our test case is a potential French test site presenting a vegetated cover not very adapted for the application of InSAR techniques. Though our algorithm remains under development, its application to the test-case revealed the limitations of DS-like techniques in areas presenting extended forest cover (i.e. of very low coherence). A second strategy relies on the optimization of the number and positions of Corner Reflectors (CR) regarding risk-oriented monitoring objectives: regional-scale surveillance, local anomaly (e.g. abandoned well) with known or unknown spatial locations. Using the deformation rate at KB-501 well at In-Salah as a reference solution, we showed that a network of moderate number of CR (density of 0.5 CR/km2) was sufficient to reveal the deformation information for both the regional-scale surveillance and the local anomaly with known location. Yet, detecting an anomaly with unknown location remains very difficult unless installing a very dense CR network (100 CR over an area defined by a radius of 4 km).

Numerical models have been calculated to study the feasibility of monitoring a supercritical CO 2... more Numerical models have been calculated to study the feasibility of monitoring a supercritical CO 2 injection in a deep saline aquifer by means of electromagnetic (EM) methods operated from the ground surface (EM being taken here in a broad sense, including DC electrical methods). Given the similarity of the problem with oil exploration, it can be anticipated that the transmitter/receiver array appropriate for CO 2 monitoring should be similar to that used in CSEM, i.e. a grounded current injection and a grid of sensors at the surface.

Several teams have proposed to follow the variation of electrical resistivity at depth in order t... more Several teams have proposed to follow the variation of electrical resistivity at depth in order to monitor the CO2 injection. This approach seems especially relevant in the case of CO2 injection in saline reservoir where the CO2 plume is expected to generate a strong increase of the electrical resistivity. Due to its greater density, supercritical CO2 occupies a much smaller

In the scope of a scenario-based risk analysis, this study aims to quantify and rank various type... more In the scope of a scenario-based risk analysis, this study aims to quantify and rank various types of epistemic uncertainties that enter into the derivation of fragility functions for common buildings. Using a numerical model of a test structure (a reinforced concrete five-story building with infill panels on the first two floors), a first type of uncertainty is introduced, consisting of the mechanical properties of the materials (i.e. Young's modulus and compressive strength for concrete, and Young's modulus and yield strength for steel). The area of longitudinal reinforcement is also modified in the model, to generate various damage mechanisms for the same structure, depending on which floor first experiences failure. Finally, another source of epistemic uncertainty is studied, by comparing different types of fragility models: fragility curves derived from dynamic analyses and fragility functions generated from a capacity spectrum approach (i.e. use of a set of natural response spectra to identify a series of performance points from the capacity curve). To this end, a ranking of the importance of different sources of uncertainty in the vulnerability analysis (i.e. mechanical properties, structural models and fragility models) is conducted by computing, for each uncertainty source, the Sobol' indices (i.e. the main effects and total effects of each source of uncertainty). This variancebased sensitivity technique presents the appealing features of both exploring the influence of input parameters over their whole range of variation and fully accounting for possible interactions between them. Nevertheless, addressing the issue of sensitivity to model uncertainty implies paying special attention to the appropriate treatment of different types of input parameters, i.e. continuous for mechanical properties or categorical in the case of fragility models. This is achieved by relying on recent advances in functional variance decomposition. For all these types of models, a uncertainty analysis in terms of the predicted number of damage buildings is carried out for a series of hypothetical scenarios.

Energy Procedia, 2009

The development of a methodology for defining safety criteria for CO 2 geological storage, realis... more The development of a methodology for defining safety criteria for CO 2 geological storage, realised under the ongoing CRISCO2 project, is depicted in this paper. Generic lists of eleven risk events and nine types of targets are proposed to serve an expert panel for identifying risk scenarios. Assessing the effects of risk events and comparing targets exposure to critical thresholds should lead to setting safety requirements. We focus on simple modelling, such as abacuses, analytical or semi-analytical models. An uncertainty management framework completes this methodology. Further work will concentrate on effectively deducing safety criteria.

Energy Procedia, 2011

The large-scale development of carbon geological storage requires the safety demonstration of thi... more The large-scale development of carbon geological storage requires the safety demonstration of this technology. The European Directive on the geological storage of carbon dioxide specifies the safety strategy to be adopted. Notably, a corrective measure plan is required in order to mitigate the potential “significant irregularities”. In this paper, we describe one measure that could be applied in case of

Energy Procedia, 2011

A prerequisite to the wide deployment of CO 2 geological storage at an industrial scale is demons... more A prerequisite to the wide deployment of CO 2 geological storage at an industrial scale is demonstrating that potential risks can be efficiently managed, which includes deploying an adequate monitoring during the injection phase and having intervention plans ready in case of major irregularity. This paper considers the injection of CO 2 into a saline formation linked to a shallower aquifer through a leaky pathway. Brine, possibly followed by CO 2 , may start migrating up through the leak if sufficient pressure buildsup in the storage reservoir. For some man-made leakages (e.g. abandoned well), and more importantly for most of the natural ones (e.g. faults, fractured zone), acting on the transfer itself (i.e. on the leaky pathway) is hardly feasible. Consequently, the corrective measure hereby investigated aims at countering the main driving force of the CO 2 upwards migration which is the pressure build-up under the leak by injecting brine into the shallower aquifer, thus creating a hydraulic barrier. Results show that this can be an efficient way to stop a leakage in less than a year instead of letting it continue for hundreds of years, even with a low and decreasing flow rate. It may also be implemented as a preventive measure, while continuing storing CO 2 .

Energy Procedia, 2011

ABSTRACT Before the full implementation of CO2 capture and storage, a demonstration of its safety... more ABSTRACT Before the full implementation of CO2 capture and storage, a demonstration of its safety is needed through the implementation of reliable risk management methods. One important aspect of risk management is the development of mitigation measures that prevent any risk to the environment or human health. This paper presents a database that includes a set of risk mitigation measures, their description and main properties, and references. They are organised in connection with a detailed approach of risk events developed into bow-tie diagrams by BRGM. The goal of the database is to help the setting up of corrective measure plans that will be mandatory for all projects under the European directive on CO2 storage.

Energy Procedia, 2009

The present study provides a set of numerical tools for modeling the geomechanical aspects relate... more The present study provides a set of numerical tools for modeling the geomechanical aspects related to the safety of geological CO2 storage, namely, caprock damage and fault reactivitation due to reservoir pressure rise. Large scale finite element models are used to describe the injection process. The change of the effective stress field is investigated. Different cracking mechanisms are considered to

Energy Procedia, 2011

... Geophysics 2007, v. 72, 2, pp. WA3 WA12. [16] K. Michael, A. Golab, V. Shulakova, J. Ennis-Ki... more ... Geophysics 2007, v. 72, 2, pp. WA3 WA12. [16] K. Michael, A. Golab, V. Shulakova, J. Ennis-King, G. Allinson, S. Sharma et al., Geological storage of CO 2 in saline aquifers - A review of the experience from existing storage operations, Inter. ... 1782-1797. [19] C. Levesque. ...

Assessment of Vulnerability to Natural Hazards, 2014

Energy Procedia, 2011

For carbon dioxide capture and storage to make an effective contribution in reducing greenhouse g... more For carbon dioxide capture and storage to make an effective contribution in reducing greenhouse gas emissions, a large number of storage sites will be required. Safety will have to be demonstrated for each of these sites. We present in this paper a simple and flexible framework to assess ...

Energy Procedia, 2011

A leakage of CO 2 from a geological storage site into an aquifer exploited for human use could ra... more A leakage of CO 2 from a geological storage site into an aquifer exploited for human use could raise concerns about potential changes of groundwater quality. We use the reactive transport code TOUGH2-ECO2N/TOUGHREACT in order to apprehend the possible geochemical ...

Natural Hazards, 2011

This paper presents a methodology to represent and propagate epistemic uncertainties within a sce... more This paper presents a methodology to represent and propagate epistemic uncertainties within a scenariobased earthquake risk model. Unlike randomness, epistemic uncertainty stems from incomplete, vague or imprecise information. This source of uncertainties still requires the development of adequate tools in seismic risk analysis. We propose to use the possibility theory to represent three types of epistemic uncertainties, namely imprecision, model uncertainty and vagueness due to qualitative information. For illustration, an earthquake risk assessment for the city of Lourdes (Southern France) using this approach is presented. Once adequately represented, uncertainties are propagated and they result in a family of probabilistic damage curves. The latter is synthesized, using the concept of fuzzy random variables, by means of indicators bounding the true probability to exceed a given damage grade. The gap between the pair of probabilistic indicators reflects the imprecise character of uncertainty related to the model, thus picturing the extent of what is ignored and can be used in risk management.

Energy Procedia, 2011

This paper deals with the electrical resistivity monitoring of the Ketzin CO2 injection pilot (CO... more This paper deals with the electrical resistivity monitoring of the Ketzin CO2 injection pilot (CO2ReMoVe EC project) through time-lapse CSEM measurements. There, 3 boreholes about 800 m deep have been especially designed for current injection at reservoir (sandstone) depth. CO2 is directly injected in a saline (∼240 g/l) aquifer. Prior modelling results indicated that the increase of electrical resistivity generated by the

International Workshop on Geomechanics and Energy, 2013

ABSTRACT Even though reservoirs targeted for CO2 storage are expected to be located in low-deform... more ABSTRACT Even though reservoirs targeted for CO2 storage are expected to be located in low-deformed tectonic settings, they can still present reservoir-scale faulted structures. Such faulting at the medium sub-seismic scale can play a significant role regarding several risk issues related to the injection-induced fluid pressure increase (fluid compartmentalization, loss of integrity in reservoir–caprock systems potentially associated with triggered seismicity and generation of leakage pathways). Yet, the characterization of the hydro-mechanical behaviour of such reservoir-scale fault structures is still lacking mainly due to the necessary seismic resolution ranging from 1 to 10 m at the reservoir scale (i.e. the “sub-seismic region”). The objective of the present study is to gain a deeper understanding of the shear reactivation of such structures subjected to pore pressure increase induced outside the CO2 injection zone. The present study relies on the combination of geological outcrop surveys in a carbonate analogue for CO2 storage reservoir (southern France) and fully coupled hydro-mechanical finite-element two-dimensional simulations. A special attention was paid to the influence of the characteristics of two specific fault components: 1. damage zone geometry and 2. fault core architecture (curvature and number of curved branches).

Energy Procedia, 2014

A possible risk of geomechanical nature related to deep injection of CO 2 is the shear reactivati... more A possible risk of geomechanical nature related to deep injection of CO 2 is the shear reactivation of faults, hence potentially leading to the creation of new leakage pathways and eventually inducing earthquakes felt at the surface. Current practices to evaluate fault stability in the domain of CO 2 storage still remain limited regarding two issues: 1. Faults are complex and heterogeneous geological systems, which do not correspond to discrete surfaces as already postulated by many authors. Reservoir-scale faults in a priori low-deformed reservoirs targeted for CO 2 storage can present high complex architecture, which might influence the hydro-mechanical behaviour of the fault system; 2. Chemical interactions (dissolution and precipitation processes, chemically-induced weakening, etc.) between CO 2 -enriched brine and the minerals constituting the fault zone can affect the mechanical stability and the transport properties of the faulted/fractured system. The research project FISIC (www.anrfisic.fr, funded by the French National research Agency) intends to overcome those limitations by accurately modelling the hydro-chemo-mechanical complexity of a fault zone. The main goal is to improve the stability analysis of a fault both undertaking pressure increase and alteration due to the presence of an acidic fluid. The progress of this research project is presented here.

Greenhouse Gases: Science and Technology, 2014

Methodologies for quantitative risk assessment regarding CO 2 storage operations are currently 16... more Methodologies for quantitative risk assessment regarding CO 2 storage operations are currently 16 scarce mostly because of the lack of experience in this field and the relatively significant 17 uncertainty degree regarding the subsurface intrinsic properties and the processes occurring 18 after the injection starts. This paper presents a practical approach designed to perform a 19 quantitative risk assessment in an uncertain context. Our approach is illustratedon a realistic 20 case study (Paris basin, France), conceived to be representative of the level of information 21 available in the early stages of a project.It follows the risk assessment principles from the 22 international standard(ISO 31000:2009), whichare adapted to account for the specificities and 23 challenges of subsurface operations. After the establishment of the context of the specific case 24 study, the main risks were identified and we analysed two different risk scenarios(risk of brine 25 2 leakage from an abandoned well, riskof subsurface use conflict).These scenarios were 26 selected to give a comprehensive overview of different types of analysis in terms of available 27 data, modelling tools and uncertainty management methodologies.The main benefit of this 28 paper is to proposeanapproach, based on existing risk assessment standards, best practices and 29 analysis tools,which allows an objective quantitative risk analysis taking into account the 30 uncertainties, and therefore enablesa fully informed decision-making whileevaluating risk 31 acceptability. 32 33 3

Energy Procedia, 2014

ABSTRACT In the present study, we applied two strategies for improving the use of InSAR/PSI techn... more ABSTRACT In the present study, we applied two strategies for improving the use of InSAR/PSI techniques for long-term monitoring ground surface deformation induced by CO2 injection areas presenting a large cover of vegetation (agricultural fields, forests, etc.). The first approach relies on advanced processing techniques using the Diffuse-Scatterers-like (DS) technique. Our test case is a potential French test site presenting a vegetated cover not very adapted for the application of InSAR techniques. Though our algorithm remains under development, its application to the test-case revealed the limitations of DS-like techniques in areas presenting extended forest cover (i.e. of very low coherence). A second strategy relies on the optimization of the number and positions of Corner Reflectors (CR) regarding risk-oriented monitoring objectives: regional-scale surveillance, local anomaly (e.g. abandoned well) with known or unknown spatial locations. Using the deformation rate at KB-501 well at In-Salah as a reference solution, we showed that a network of moderate number of CR (density of 0.5 CR/km2) was sufficient to reveal the deformation information for both the regional-scale surveillance and the local anomaly with known location. Yet, detecting an anomaly with unknown location remains very difficult unless installing a very dense CR network (100 CR over an area defined by a radius of 4 km).

Numerical models have been calculated to study the feasibility of monitoring a supercritical CO 2... more Numerical models have been calculated to study the feasibility of monitoring a supercritical CO 2 injection in a deep saline aquifer by means of electromagnetic (EM) methods operated from the ground surface (EM being taken here in a broad sense, including DC electrical methods). Given the similarity of the problem with oil exploration, it can be anticipated that the transmitter/receiver array appropriate for CO 2 monitoring should be similar to that used in CSEM, i.e. a grounded current injection and a grid of sensors at the surface.

Several teams have proposed to follow the variation of electrical resistivity at depth in order t... more Several teams have proposed to follow the variation of electrical resistivity at depth in order to monitor the CO2 injection. This approach seems especially relevant in the case of CO2 injection in saline reservoir where the CO2 plume is expected to generate a strong increase of the electrical resistivity. Due to its greater density, supercritical CO2 occupies a much smaller

In the scope of a scenario-based risk analysis, this study aims to quantify and rank various type... more In the scope of a scenario-based risk analysis, this study aims to quantify and rank various types of epistemic uncertainties that enter into the derivation of fragility functions for common buildings. Using a numerical model of a test structure (a reinforced concrete five-story building with infill panels on the first two floors), a first type of uncertainty is introduced, consisting of the mechanical properties of the materials (i.e. Young's modulus and compressive strength for concrete, and Young's modulus and yield strength for steel). The area of longitudinal reinforcement is also modified in the model, to generate various damage mechanisms for the same structure, depending on which floor first experiences failure. Finally, another source of epistemic uncertainty is studied, by comparing different types of fragility models: fragility curves derived from dynamic analyses and fragility functions generated from a capacity spectrum approach (i.e. use of a set of natural response spectra to identify a series of performance points from the capacity curve). To this end, a ranking of the importance of different sources of uncertainty in the vulnerability analysis (i.e. mechanical properties, structural models and fragility models) is conducted by computing, for each uncertainty source, the Sobol' indices (i.e. the main effects and total effects of each source of uncertainty). This variancebased sensitivity technique presents the appealing features of both exploring the influence of input parameters over their whole range of variation and fully accounting for possible interactions between them. Nevertheless, addressing the issue of sensitivity to model uncertainty implies paying special attention to the appropriate treatment of different types of input parameters, i.e. continuous for mechanical properties or categorical in the case of fragility models. This is achieved by relying on recent advances in functional variance decomposition. For all these types of models, a uncertainty analysis in terms of the predicted number of damage buildings is carried out for a series of hypothetical scenarios.

Energy Procedia, 2009

The development of a methodology for defining safety criteria for CO 2 geological storage, realis... more The development of a methodology for defining safety criteria for CO 2 geological storage, realised under the ongoing CRISCO2 project, is depicted in this paper. Generic lists of eleven risk events and nine types of targets are proposed to serve an expert panel for identifying risk scenarios. Assessing the effects of risk events and comparing targets exposure to critical thresholds should lead to setting safety requirements. We focus on simple modelling, such as abacuses, analytical or semi-analytical models. An uncertainty management framework completes this methodology. Further work will concentrate on effectively deducing safety criteria.

Energy Procedia, 2011

The large-scale development of carbon geological storage requires the safety demonstration of thi... more The large-scale development of carbon geological storage requires the safety demonstration of this technology. The European Directive on the geological storage of carbon dioxide specifies the safety strategy to be adopted. Notably, a corrective measure plan is required in order to mitigate the potential “significant irregularities”. In this paper, we describe one measure that could be applied in case of

Energy Procedia, 2011

A prerequisite to the wide deployment of CO 2 geological storage at an industrial scale is demons... more A prerequisite to the wide deployment of CO 2 geological storage at an industrial scale is demonstrating that potential risks can be efficiently managed, which includes deploying an adequate monitoring during the injection phase and having intervention plans ready in case of major irregularity. This paper considers the injection of CO 2 into a saline formation linked to a shallower aquifer through a leaky pathway. Brine, possibly followed by CO 2 , may start migrating up through the leak if sufficient pressure buildsup in the storage reservoir. For some man-made leakages (e.g. abandoned well), and more importantly for most of the natural ones (e.g. faults, fractured zone), acting on the transfer itself (i.e. on the leaky pathway) is hardly feasible. Consequently, the corrective measure hereby investigated aims at countering the main driving force of the CO 2 upwards migration which is the pressure build-up under the leak by injecting brine into the shallower aquifer, thus creating a hydraulic barrier. Results show that this can be an efficient way to stop a leakage in less than a year instead of letting it continue for hundreds of years, even with a low and decreasing flow rate. It may also be implemented as a preventive measure, while continuing storing CO 2 .

Energy Procedia, 2011

ABSTRACT Before the full implementation of CO2 capture and storage, a demonstration of its safety... more ABSTRACT Before the full implementation of CO2 capture and storage, a demonstration of its safety is needed through the implementation of reliable risk management methods. One important aspect of risk management is the development of mitigation measures that prevent any risk to the environment or human health. This paper presents a database that includes a set of risk mitigation measures, their description and main properties, and references. They are organised in connection with a detailed approach of risk events developed into bow-tie diagrams by BRGM. The goal of the database is to help the setting up of corrective measure plans that will be mandatory for all projects under the European directive on CO2 storage.

Energy Procedia, 2009

The present study provides a set of numerical tools for modeling the geomechanical aspects relate... more The present study provides a set of numerical tools for modeling the geomechanical aspects related to the safety of geological CO2 storage, namely, caprock damage and fault reactivitation due to reservoir pressure rise. Large scale finite element models are used to describe the injection process. The change of the effective stress field is investigated. Different cracking mechanisms are considered to

Energy Procedia, 2011

... Geophysics 2007, v. 72, 2, pp. WA3 WA12. [16] K. Michael, A. Golab, V. Shulakova, J. Ennis-Ki... more ... Geophysics 2007, v. 72, 2, pp. WA3 WA12. [16] K. Michael, A. Golab, V. Shulakova, J. Ennis-King, G. Allinson, S. Sharma et al., Geological storage of CO 2 in saline aquifers - A review of the experience from existing storage operations, Inter. ... 1782-1797. [19] C. Levesque. ...

Assessment of Vulnerability to Natural Hazards, 2014

Energy Procedia, 2011

For carbon dioxide capture and storage to make an effective contribution in reducing greenhouse g... more For carbon dioxide capture and storage to make an effective contribution in reducing greenhouse gas emissions, a large number of storage sites will be required. Safety will have to be demonstrated for each of these sites. We present in this paper a simple and flexible framework to assess ...

Energy Procedia, 2011

A leakage of CO 2 from a geological storage site into an aquifer exploited for human use could ra... more A leakage of CO 2 from a geological storage site into an aquifer exploited for human use could raise concerns about potential changes of groundwater quality. We use the reactive transport code TOUGH2-ECO2N/TOUGHREACT in order to apprehend the possible geochemical ...

Natural Hazards, 2011

This paper presents a methodology to represent and propagate epistemic uncertainties within a sce... more This paper presents a methodology to represent and propagate epistemic uncertainties within a scenariobased earthquake risk model. Unlike randomness, epistemic uncertainty stems from incomplete, vague or imprecise information. This source of uncertainties still requires the development of adequate tools in seismic risk analysis. We propose to use the possibility theory to represent three types of epistemic uncertainties, namely imprecision, model uncertainty and vagueness due to qualitative information. For illustration, an earthquake risk assessment for the city of Lourdes (Southern France) using this approach is presented. Once adequately represented, uncertainties are propagated and they result in a family of probabilistic damage curves. The latter is synthesized, using the concept of fuzzy random variables, by means of indicators bounding the true probability to exceed a given damage grade. The gap between the pair of probabilistic indicators reflects the imprecise character of uncertainty related to the model, thus picturing the extent of what is ignored and can be used in risk management.