Alex Hansen NTNU-UiO Porous Media Laboratory, Norway
Title: A New Kind of Thermodynamics for Two-Phase Flow in Porous Media
Abstract: Homogenization is the standard approach to upscaling immiscible two-phase flow in porous media from the pore scale to the Darcy scale. The trouble with homogenization techniques is that they can only produce averages of existing variables and not new types of variables.
Statistical mechanics does produce new types of variables when scaling up thermal systems from the molecular scale to the continuum scale. Temperature is an example of such a variable. It connects the mechanistic description at the molecular level with a thermodynamic description at the continuum level. The trouble with statistical mechanics is that it demands equilibrium. Immiscible two-phase flow in porous media is not an equilibrium process.
It is, however, possible to map immiscible two-phase flow in porous media onto an equivalent equilibrium process through a trick. This makes it possible to formulate a version of statistical mechanics for this problem.
This leads to a thermodynamics-like description at the Darcy scale where the fluid velocities play the roles of internal energy and free energies. New variables such as the agiture – a temperature equivalent – emerge.
Another emergent variable at the Darcy scale is the co-moving velocity. This variable has no equivalent in ordinary thermodynamics. The co-moving velocity has many interesting properties, many of which remain mysterious. Perhaps the most surprising one is that it leads to a differential equation between the relative permeabilities. The simplest solution to this equation gives the Corey relative permeabilities.
Bio: Alex Hansen did his undergraduate work at the University of Oslo and his PhD in theoretical physics at Cornell University (1986), followed by postdoctoral positions at Ecole Normale Supérieure in Paris and the University of Cologne. He was CNRS Chargé de Recherche at the University of Rennes 1 in 1992-1994 before being appointed professor of physics at the Norwegian University of Science and Technology (NTNU) in Trondheim. In 2017, Hansen became director of the newly created PoreLab which is a center of excellence funded by the Research Council of Norway and shared between the NTNU and the University of Oslo. Hansen is member of the Norwegian Academy of Sciences and Letters, the Royal Norwegian Society of Science and Letters, and the Norwegian Academy of Technical Sciences. He received a Dr. h. c. degree from the University of Rennes 1 in 2009. Hansen’s main research interests concern the intersection between fluid dynamics and statistical mechanics in porous media.
Title: Inertia, non-equilibrium, and momentum conservation in porous media
Bio: Ivan Lunati is a physicist with interests that span theory, scientific computing, and experiments. He holds a degree summa cum laude from the University of Milan and a PhD from ETH Zurich. He has been Swiss National Science Foundation professor at the University of Lausanne, where he founded and led the Multiphase and Hydrosystems group, and worked on many theoretical and computational aspects of porous media (e.g., interface dynamics and pore-scale processes; soil evaporation; multiscale/multiphysics modeling; machine learning for uncertainty quantification). In 2020, he joined Empa, where he is currently the Head of the Laboratory for Computational Engineering, which is committed to integrate mechanistic simulations, data-driven modeling, and experiments. His current research is intrinsically interdisciplinary and embraces, in addition to porous media, atomistic simulations, artificial intelligence, electro-optical diagnostic, network science, epidemiology, and virus transport.
Lucia Mancini ZAG - Slovenian National Building and Civil Engineering Institute, Slovenia
Title: Advanced multi-scale and multi-modal three-dimensional imaging and modelling of flow properties in porous rocks
Abstract: The textural and geometrical properties of pore networks, including pore size distribution, shape, connectivity, and tortuosity, play a crucial role in the storage and migration of geofluids within porous reservoir rocks. Variability in these properties arises from primary depositional conditions, diagenetic processes, and deformation, posing significant challenges for reservoir characterization and planning in energy exploitation or CO2 storage scenarios. Accurate volume estimation and fluid transport properties are essential and can be derived through the integration of outcrop analogues, core samples, and petrophysical analysis. The recent advances in X-ray and neutron 3D imaging techniques in static and dynamic conditions, coupled with computational fluid dynamics, can offer a deeper understanding of how the pore network properties influence fluid transport. In addition, dual porosity/permeability synthetic models can be constructed to evaluate the impact of macrofractures on storage and transport in porous carbonate reservoir analogues at the microscale. In this talk the results of several case studies will be presented.
Bio: Dr. Mancini is a material science physicist who has lead the TomoLab facility (two instruments) at Elettra devoted to microfocus X-ray Computed Tomography since 2005. Since May 2022 she has been working as senior researcher in the Department of Materials of the Slovenian National Building and Civil Engineering Institute in Ljubljana (Slovenia). Her research activity deals with: hard 2D and 3D X-ray imaging of solid and liquid materials, application to the morphological and textural characterization of geomaterials (e.g. igneous, reservoir and metamorphic rocks, paleontological studies, …), innovative materials (e.g. composites, light concrete, green batteries, …), natural and cultural heritage studies (e.g. paleo-teeth and fossil bones, ancient musical instruments, insects in amber, ...), in situ and real-time CT experiments under high-temperature, mechanical testing, operando conditions. The investigation methods are mainly absorption and phase-contrast X-ray and neutron imaging often combined with X-ray and neutron diffraction and scattering-based techniques. She has a strong background in 3D/4D data processing and analysis and, in this framework, since 2002 has been coordinating the Pore3D project for the development and maintenance of a software library devoted to the processing and quantitative analysis of CT images (https://github.com/ElettraSciComp/Pore3D).
Title: Validating computational models for carbon storage
Abstract: As is common for subsurface applications, the planning and operation of geological carbon storage relies heavily on computational models. Arguably, several decades of experience from the extraction of subsurface resources support the validity of these tools, in particular during the active carbon dioxide injection and early post-injection phase. However, validation of long-term carbon storage performance, on the time-scales of hundreds of years after injection, cannot directly be justified by either existing engineering practice nor natural analogues.
The FluidFlower validation and forecasting study was specifically designed to provide validation data for carbon storage. Moreover, by conducting a multi-institutional and multidisciplinary double-blind study, we were able to address the forecasting skill of the carbon storage simulation community. In this talk we give an overview of the results of the study, both from the perspective of model validation and assessment of forecasting skill.
Bio: Professor Jan Martin Nordbotten is a mathematician with a strong interest for interdisciplinary collaborations. He completed his PhD at the age of 22 as the youngest ever in Norway, and became a full professor at the age of 27. As early as in his PhD, he worked simultaneously on numerical analysis, while collaborating with environmental engineers on issues related to CO2 storage. Since then, he has established interdisciplinary collaborations in biology (theoretical evolution), ecology (water-plant dynamics), geosciences (multiphase subsurface flows, deformation), biomedicine (image processing, fluid dynamics) and computer science (image rendering). Nordbotten has co-authored papers with over 130 researchers, and was the primary author on the first text-book on modelling and simulation of CO2 storage.
Title: Orthogonally different mineral reactions, same outcome of permeability reduction: How can this be?
Abstract: Sustainable energy technologies that involve subsurface gas storage require reliable containment of buoyant fluids. An example is geologic carbon sequestration in which large volumes of CO2 are injected deep underground into porous formations with overlying caprocks. Storage security could be jeopardized if fractures exist, so strategies are needed to seal permeable flow paths. In our work, two orthogonally different mineral reaction scenarios were explored. In one case minerals precipitated and in the other case minerals dissolved, but both cases had the same outcome of reduced fracture permeability. How can this be? In the first case, vein minerals from a mudrock sample of the Wolfcamp formation provided insights about syntaxial mineral growth in a fracture. Dolomite and other carbonate minerals had precipitated in the fracture, closing it off to fluid flow. In the second case, a carbonate-rich shale was reacted leading to calcite dissolution along fracture surfaces. Subsequent compression from normal stress collapsed the altered layer, sealing the fracture and reducing permeability. These studies show that multiple mineral reaction mechanisms can achieve fracture sealing and permeability reduction, a favorable outcome in subsurface applications where the goal is to reduce leakage risks.
Bio: Catherine Peters is the Magee Professor of Geosciences and Geological Engineering, in the Department of Civil & Environmental Engineering at Princeton University. Dr. Peters is an expert in environmental chemistry and geochemistry, known for her leadership in sustainable energy technologies. She is a Fellow of the Association of Environmental Engineering and Science Professors (AEESP), and served as president in 2002. She is Editor-in-Chief of Environmental Engineering Science. She teaches courses in environmental chemistry, energy and the environment, and sustainable design.
Title: Simulating flow and solute transport in subsurface environments: From pore-scale to beyond
Abstract: Research of the multi-scale, multi-phase, and multi-processes system is of great interest in understanding subsurface environments. However, the coupled flow and transport processes are complex yet challenging for model development and utilization. There have been numerous object-oriented and easy-to-use models/codes across scales to facilitate consistency, continuity, and reproducibility in subsurface research. In addition, pioneer efforts on upscaling also inspire the development of hybrid multi-scale models. It is then critical to intercompare codes and approaches for their evaluation or validation, and propel discussions for optimizing the codes and the development of the next-generation numerical approaches. In this talk, we present a suite of at-scale and multi-scale models that we developed and utilized in recent years for simulating flow and transport processes, with intercomparison and benchmarking cases, including: (1) pore-scale models for simulating flow, solute transport and biofilm growth in porous media; (2) Darcy-scale models for simulating thermo-hydrological processes in frozen soils; (3) regional-scale groundwater models for simulating groundwater-surface interactions; (4) hybrid multi-scale models (pore- to Darcy-scale) for numerical upscaling.
Bio: Xiaofan Yang is the Assistant Dean and Professor in Hydrology of the Faculty of Geographical Science at Beijing Normal University (BNU), China. She holds a BEng from Tsinghua University (China), a MSc from KTH (Sweden) and a PhD from Kansas State University (USA). Before joining BNU, she was a Scientist at the Pacific Northwest National Laboratory (PNNL) of the U.S. Department of Energy (US DOE). Her research interests include subsurface hydrology, computational hydrology and multiscale modeling and simulations, with specific focus on reactive transport modeling, groundwater modeling, flow and reactive transport in porous media. She is currently the Vice President of the Terrestrial Working Group of the International Arctic Science Committee, member of the National Chapter Committee of the InterPORE, and serves as the Associate Editor of Journal of Hydrology: Regional Studies and Hydrological Processes as well as the Editor of Journal of Contaminant Hydrology.
Title: Physical Insights into Phase Transition and Capillary Transport in Porous Media with In-situ NMR-MRI Characterization
Abstract: Interfacial transport and phase transition are essential for a large variety of energy and sustainability applications, while in-situ characterization provides instrumental ways of probing and enhancing thermal-fluid transport in porous media. In this talk, I will share our recent progresses on water evaporation and ice melting in homogeneous and heterogeneous opaque porous media, by utilizing non-destructive nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI). By characterizing the amplitude variation of NMR transverse relaxation time T2, we find that cavitation occurs across the entire porous media along with the water evaporation from open surface. Disconnected void clusters at different depths in the porous medium are also observed from MRI scanning and optical images. These evidences confirm the occurrence of cavitation in porous media because the water is stretched to metastable state by large capillary pressure from the evaporating meniscus. Moreover, transient T2 distributions from NMR enable us to reveal the substantial role of inherent throat and pore confinements in ice melting among various porous media. The increase in minimum T2 offers new findings on how the confinement between ice crystal and particle surface evolves inside the pores of mushy zone. The evolution of melting front and 3D spatial distribution of water content are directly visualized by a stack of temporal cross-section images from MRI, in consistency with the associated NMR results. For heterogeneous porous media like lunar regolith simulant, the T2 curves show two distinct pore size distributions with different pore-scale melting dynamics, and the maximum T2 keeps increasing throughout the whole ice melting process instead of reaching steady for homogeneous porous media. These transport and phase change physics opens up new avenues to develop novel solutions for water-energy-food nexus and in-situ resource utilization towards deep space exploration.
Bio: Prof. TieJun (TJ) Zhang is a Professor of Mechanical Engineering at the Khalifa University and a Member of the Mohammed bin Rashed Academy of Scientists (UAE’s National Academy). He also serves as the Theme Leader of Abu Dhabi Virtual Research Institute for Sustainability (Energy). He was a Visiting Assistant Professor at the Massachusetts Institute of Technology (MIT) and a Postdoctoral Research Associate at the Rensselaer Polytechnic Institute (RPI) in USA. As one of World’s Top 2% of Scientists, he has over 160 peer-reviewed publications and multiple international patents. Prof. Zhang is the recipient of the UAE National Research Foundation University-Industry Research Collaboration Award, the Abu Dhabi Award for Research Excellence, and the US National Academy of Sciences Arab-American Frontiers Fellowship Award. He has been the Principal Investigator of many research projects (~US$15 millions) on energy, water and micro/nanotechnologies. Prof. Zhang is an Associate Editor of ASME Journal of Micro and Nano-Manufacturing. He was the co-chair (Arab-side) of the Fourth Arab-American Frontiers of Science, Engineering and Medicine Symposium between USA and 22 Arab countries (organized by the US National Academies of Sciences, Engineering and Medicine). He has been an invited reviewer for many international research proposals, doctoral dissertations and over 60 scientific journals.
