Thermal effects on geologic carbon storage

The final publication is available at Springer via http://dx.doi.org/10.1016/j.earscirev.2016.12.011One of the most promising ways to significantly reduce greenhouse gases emissions, while carbon-free energy sources are developed, is Carbon Capture and Storage (CCS). Non-isothermal effects play a major role in all stages of CCS. In this paper, we review the literature on thermal effects related to CCS, which is receiving an increasing interest as a result of the awareness that the comprehension of non-isothermal processes is crucial for a successful deployment of CCS projects. We start by reviewing CO2 transport, which connects the regions where CO2 is captured with suitable geostorage sites. The optimal conditions for CO2 transport, both onshore (through pipelines) and offshore (through pipelines or ships), are such that CO2 stays in liquid state. To minimize costs, CO2 should ideally be injected at the wellhead in similar pressure and temperature conditions as it is delivered by transport. To optimize the injection conditions, coupled wellbore and reservoir simulators that solve the strongly non-linear problem of CO2 pressure, temperature and density within the wellbore and non-isothermal two-phase flow within the storage formation have been developed. CO2 in its way down the injection well heats up due to compression and friction at a lower rate than the geothermal gradient, and thus, reaches the storage formation at a lower temperature than that of the rock. Inside the storage formation, CO2 injection induces temperature changes due to the advection of the cool injected CO2, the Joule-Thomson cooling effect, endothermic water vaporization and exothermic CO2 dissolution. These thermal effects lead to thermo-hydro-mechanical-chemical coupled processes with non-trivial interpretations. These coupled processes also play a relevant role in “Utilization” options that may provide an added value to the injected CO2, such as Enhanced Oil Recovery (EOR), Enhanced Coal Bed Methane (ECBM) and geothermal energy extraction combined with CO2 storage. If the injected CO2 leaks through faults, the caprock or wellbores, strong cooling will occur due to the expansion of CO2 as pressure decreases with depth. Finally, we conclude by identifying research gaps and challenges of thermal effects related to CCS.Peer ReviewedPostprint (author's final draft

Numerical modelling of fluid flow and particle transport in a riugh rock fracture during shear

The effects of both translational and rotary shear on particle transport Ander coupled shear-flow test conditions in a single rouge rock fracture were numerically investigated in this thesis. A pair of digitalized surfaces of a 250x250 mm concrete rough fracture replica were numerically manipulated to simulate the translational and rotary shearing processes of the sample, using Finite Element Method (FEM). Different fluid flow situations were cosidered. For the translational shear three different flow patterns-unidirectional, bi-directional and radial-have been taken into account. For rotary shear, only the radial flow patterns have been considered. Furthermore, the effect of the fracture surface roughness on the aperture and transmissivity fields was evaluated using semi-variograms. The results of flow and particle transport simulations show that translational shear yields a channelling effect in the direction perpendicular to shear direction, creating high transmissivity channels through which the particles travelling in this direction can travel fast and without being delayed by bypassing low transmissivity areas. Bi-directional flow patterns show clearly the shortcomings of the conventional shear-flow tests in the laboratory with a unidirectional flow. In radial flow patterns, while translational shear generates an anisotropic particle transport behaviour with faster transport perpendicular to shear direction, rotary shear presents isotropic flow field and particle paths in all directions

Numerical modelling of fluid flow and particle transport in a riugh rock fracture during shear

The effects of both translational and rotary shear on particle transport Ander coupled shear-flow test conditions in a single rouge rock fracture were numerically investigated in this thesis. A pair of digitalized surfaces of a 250x250 mm concrete rough fracture replica were numerically manipulated to simulate the translational and rotary shearing processes of the sample, using Finite Element Method (FEM). Different fluid flow situations were cosidered. For the translational shear three different flow patterns-unidirectional, bi-directional and radial-have been taken into account. For rotary shear, only the radial flow patterns have been considered. Furthermore, the effect of the fracture surface roughness on the aperture and transmissivity fields was evaluated using semi-variograms. The results of flow and particle transport simulations show that translational shear yields a channelling effect in the direction perpendicular to shear direction, creating high transmissivity channels through which the particles travelling in this direction can travel fast and without being delayed by bypassing low transmissivity areas. Bi-directional flow patterns show clearly the shortcomings of the conventional shear-flow tests in the laboratory with a unidirectional flow. In radial flow patterns, while translational shear generates an anisotropic particle transport behaviour with faster transport perpendicular to shear direction, rotary shear presents isotropic flow field and particle paths in all directions

Hubs and clusters approach to unlock the development of carbon capture and storage – Case study in Spain

Many countries have assigned an indispensable role for carbon capture and storage (CCS) in their national climate change mitigation pathways. However, CCS deployment has stalled in most countries with only limited commercial projects realised mainly in hydrocarbon-rich countries for enhanced oil recovery. If the Paris Agreement is to be met, then this progress must be replicated widely, including hydrocarbon-limited countries. In this study, we present a novel source-to-sink assessment methodology based on a hubs and clusters approach to identify favourable regions for CCS deployment and attract renewed public and political interest in viable deployment pathways. Here, we apply this methodology to Spain, where fifteen emission hubs from both the power and the hard-to-abate industrial sectors are identified as potential CO2 sources. A priority storage structure and two reserves for each hub are selected based on screening and ranking processes using a multi-criteria decision-making method. The priority source-to-sink clusters are identified indicating four potential development regions, with the North-Western and North-Eastern Spain recognised as priority regions due to resilience provided by different types of CO2 sources and geological structures. Up to 68.7 Mt CO2 per year, comprising around 21% of Spanish emissions can be connected to clusters linked to feasible storage. CCS, especially in the hard-to-abate sector, and in combination with other low-carbon energies (e.g., blue hydrogen and bioenergy), remains a significant and unavoidable contributor to the Paris Agreement's mid-century net-zero target. This study shows that the hubs and clusters approach can facilitate CCS deployment in Spain and other hydrocarbon-limited countries

Social and environmental aspects of the energy transition

The need to promote a swift, efficient and fair energy transition to clean, secure and efficient energy production, storage, transport, and consumption is a major challenge for the future of the planet ( EC 2020 ). Currently, massive emissions of greenhouse gases ( particularly CO2 ) and other pollutants are changing global climate, and the lasts report of the Intergovernmental Panel on Climate Change ( IPCC 2018 ) advised that keeping the temperature increase below 1.5 ºC will require drastic, urgent and internationally coordinated actions. These initiatives will greatly affect advanced economies, characterized by high energy consumption, which should seek for clean and secure local energy sources, but they are also highly relevant for quickly developing countries, whose biodiversity, natural resources and standards of living are at risks due to over exploitation of local resources or to accumulation of waste products of energy production technologies coming from elsewhere. These processes of transition, though, have generated a variety of social and environmental impacts and, at the same time, have triggered complex questions about sustainability and social acceptance ( i.e. Sánchez-Zapata et al. 2019 for wind and solar energy production in Spain ). Social and environmental aspects of the transition to clean, secure and efficient energy production, storage, transport, and consumption should then be fully incorporated into research on new energy sources to ensure its sustainability.Peer reviewe

CO2 Long-term Periodic Injection Experiment at Mont Terri (CO2LPIE).

Peer reviewe

11th EGU Galileo Conference: Solid Earth and Geohazards in the Exascale Era Consensual Document

The 11th Galileo Conference in Barcelona (May 23-26, 2023) addressed Exascale computing challenges in geosciences. With 78 participants from 15 countries, it focused on European-based research but welcomed contributions from worldwide institutions. The conference had four sessions covering HPC applications, data workflows, computational geosciences, and EuroHPC infrastructures. It featured keynote presentations, poster sessions, and breakout sessions, including Master Classes for 22 Early Career Scientists supported by EGU. This document represents the consensus among participants, capturing outcomes from breakout sessions and acknowledging diverse opinions and approaches.The 11th Galileo Conference of the European Geosciences Union (EGU) focused on "Solid Earth and Geohazards in the Exascale Era." This abstract presents the main outcomes and conclusions from the conference breakout sessions, which aimed to provide recommendations for the future of solid earth research. The discussions highlighted the challenges and opportunities associated with high-performance computing (HPC) in solid earth sciences. The key findings include the need for collaboration between computer scientists and solid earth domain-specific scientists, the importance of portability software layers for different hardware architectures, the adoption of programming models for easier development and deployment of applications, the necessity of HPC training at all career stages, the improvement of accessibility and authentication mechanisms for European machines, and the readiness of urgent computing services for natural catastrophes. The conference also emphasized the significance of sustainable funding, software engineering best practices, and the development of modular and interoperable codes and workflows. Overall, the conference provided insights into the current status of computational solid earth research and offered recommendations for future advancements in the field.European Geosciences Union (EGU), the EuroHPC Center of Excellence for Exascale in Solid Earth (ChEESE) under Grant Agreement No 101093038 (https://cheese2.eu), and the European Union's Next Generation/PRTR Program through grant PCI2022-134973-2.Peer reviewe

Renewable Energy Production

Coordinator: Hernán Míguez.Peer reviewe

Caprock Integrity and Induced Seismicity from Laboratory and Numerical Experiments

CO2 leakage is a major concern for geologic carbon storage. To assess the caprock sealing capacity and the strength of faults, we test in the laboratory the rock types involved in CO2 storage at representative in-situ conditions. We use the measured parameters as input data to a numerical model that simulates CO2 injection in a deep saline aquifer bounded by a low-permeable fault. We find that the caprock sealing capacity is maintained and that, even if a fault undergoes a series of microseismic events or aseismic slip, leakage is unlikely to occur through ductile clay-rich faults. © 2017 The Authors. Published by Elsevier Ltd.V.V. acknowledges financial support from the “TRUST" project (European Community's Seventh Framework Programme FP7/2007-2013 under grant agreement n. 309607) and from “FracRisk" project (European Community's Horizon 2020 Framework Programme H2020-EU.3.3.2.3 under grant agreement n. 640979). R.M. acknowledges partial support from the Center for Geologic Storage of CO2, an EFRC funded by the U.S. DOE, Office of Science, BES, under Award DE-SC0C12504.Peer reviewe

CO2 injection in liquid state as an efficient storage concept for reducing greenhouse gas emissions

Deep geological formations have a great potential to significantly reduce carbon dioxide (CO2) emissions to the atmosphere through both geologic carbon storage and geothermal energy. Geologic carbon storage permits storing large amounts of CO2, in the order of tens of millions of tons of CO2 per storage site. However, it may be argued that the economic costs are excessively high and that a CO2 should be utilized somehow to make injection profitable. A promising solution is to use CO2 as circulating fluid to produce geothermal energy because CO2 is more efficient than water. We propose to inject CO2 in liquid state, rather than in supercritical conditions, which are the conditions at which CO2 will stay once it equilibrates with the pressure and temperature of storage formations. Liquid CO2 has a higher density than supercritical CO2, which significantly reduces the required compression energy at the wellhead because CO2 flows downwards mainly by gravity. If liquid CO2 injection is combined with production of supercritical CO2 from the storage formation a thermosiphon is created, which permits circulating CO2 at a minimum operational costs and generate carbon-free geothermal energy. The potential downside of liquid CO2 injection is that the rock around the injection well is cooled down, which generates contraction and thermal stress reduction, which eventually could reactivate fractures or even promote hydraulic fractures. We assess the geomechanical stability of the caprock as a result of this cooling and find that a stress redistribution occurs around the cooled region, which tightens the caprock. Overall, liquid CO2 injection is an energetically efficient injection concept that can permit both reducing CO2 emissions to the atmosphere and to generate geothermal energy. The targeted audience are scientists and engineers interested in geothermal energy and coupled processes occurring in the subsurface.Peer reviewe