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Understanding the formation of rapid degassing chimneys in sedimentary stacks using supercomputing

Applicant Räss Ludovic
Number 178075
Funding scheme Early Postdoc.Mobility
Research institution
Institution of higher education Institution abroad - IACH
Main discipline Geophysics
Start/End 01.07.2018 - 31.12.2019
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All Disciplines (2)

Discipline
Geophysics
Fluid Dynamics

Keywords (6)

Methane hydrates; Poromechanics; High-Performance Computing; Multi-phase flow; Numerical modelling; Hydro-Mechanical coupling

Lay Summary (French)

Lead
Les formations rocheuses sédimentaires constituent une partie importante des bassins sédimentaires ainsi que des marges continentales passives. La porosité non-négligeable de ces formations leur confère un potentiel de réservoir convoité, autant en termes d’exploration que de stockage. En particuliers dans les régions subpolaires, les bassins sédimentaires contiennent d’importantes quantités de gaz tel le méthane, stocké sous forme d’hydrates, un mélange de gaz et d’eau glacé. Suite à un changement des conditions locales de pression et/ou de température, les hydrates de méthanes peuvent sublimer et relâcher d’importantes quantités de méthane gazeux. De récentes études géophysiques reportent la migration de ces gaz via des « chenaux » tubulaires. Alors que la source ainsi que les volumes relâchés sont activement monitorées, les mécanismes de migration du gaz sous forme de chenaux tubulaires restent quant à eux, partiellement énigmatiques.
Lay summary

Contenu et objectifs du travail de recherche

Je propose d’utiliser des modèles numériques multi-phases afin d’apporter des éléments de réponse quant aux potentiels mécanismes de transferts de fluides verticaux dans les roches sédimentaires. Je suggère que la formation ainsi que la propagation localisée des fluides ainsi que des gaz contenus dans les pores des roches serait dû à des interactions hydromécaniques. Afin de vérifier ces hypothèses, je propose d’implémenter des modèles à haute résolution utilisant une approche de calcul à haute performance sur des supercalculateurs. Une étude systématique des paramètres importants me permettra d’isoler les concepts clé contrôlant un transfert rapide et localisé des fluides et des gaz. Je propose finalement des générer des sismogrammes synthétiques dans les modèles obtenus afin de corréler ces derniers avec des données géophysiques de terrain. Le travail de recherche proposé lie des méthodes computationnelles de calcul à haute performance avec des méthodes géophysiques afin de comprendre les mécanismes physiques qui gouvernent la formation de chenaux de dégazage dans les roches poreuses de nombreux bassins sédimentaires.

Contexte scientifique et social du projet de recherche

Ce travail générera des connaissances nouvelles quant à la compréhension des mécanismes physiques de transferts localisés de fluides et gaz dû à un couplage de processus hydrologiques et mécaniques. Une meilleure compréhension de ces processus permettra de potentiellement réduire les impacts de gaz à effets de serre, tel le méthane, sur l’Homme et la société, ainsi que d’apporter de possible outils quant à la thématique du changement climatique.

Direct link to Lay Summary Last update: 24.04.2018

Responsible applicant and co-applicants

Publications

Publication
Efficient parallel random field generator for large 3-D geophysical problems
Räss Ludovic, Kolyukhin Dmitriy, Minakov Alexander (2019), Efficient parallel random field generator for large 3-D geophysical problems, in Computers & Geosciences, 131, 158-169.
Modelling thermomechanical ice deformation using a GPU-based implicit pseudo-transient method (FastICE v1.0)
RässLudovic, LiculAleksandar, HermanFrédéric, PodladchikovYuri Y., SuckaleJenny, Modelling thermomechanical ice deformation using a GPU-based implicit pseudo-transient method (FastICE v1.0), in Geoscientific Model Development, 1.

Collaboration

Group / person Country
Types of collaboration
Alexander Minakov/CEED UiO Oslo Norway (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Bryan Davy/GNS Science Lower Hutt New Zealand (Oceania)
- in-depth/constructive exchanges on approaches, methods or results
Lowell Stott/USC Los Angeles United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
JuliaCon 2019 Talk given at a conference Porting a Massively Parallel Multi-GPU Application to Julia: a 3-D Nonlinear Multi-Physics Flow Solver 22.07.2019 Baltimore, MD, United States of America Räss Ludovic;
PASC19 Talk given at a conference Nonlinear multi-physics 3-D solver: from CUDA C + MPI to Julia 12.06.2019 Zurich, Switzerland Räss Ludovic;
EGU General Assembly 2019 Talk given at a conference Efficient solvers for multi-physics applications on HPC systems 08.04.2019 Vienna, Austria Räss Ludovic;
GPU Technology Conference Talk given at a conference Resolving Spontaneous Nonlinear Multi-Physics Flow Localisation in 3-D - Tackling Hardware Limit 17.03.2019 San Jose, CA, United States of America Räss Ludovic;
AGU Fall Meeting 2018 Talk given at a conference Towards efficient iterative matrix-free solvers 09.12.2018 Washington DC, United States of America Räss Ludovic;
AGU Fall Meeting 2018 Talk given at a conference Towards efficient iterative matrix-free solvers 09.12.2018 Washington DC, United States of America Räss Ludovic;


Self-organised

Title Date Place
Swiss Geocomputing Centre - Kick-off workshop 15.10.2018 Lausanne, Switzerland

Knowledge transfer events

Active participation

Title Type of contribution Date Place Persons involved
Stanford Earth Skillshare Talk 10.05.2019 Stanford, CA, United States of America Räss Ludovic;


Abstract

Sedimentary rocks are present all over the world and form large sedimentary basins on continental shelves. Since they are porous rocks, their available fluid-filled pore space exhibits a large storage potential and is used as reservoir in CO2 and wastewater storage operations. Sedimentary rocks also naturally sequestrate enormous quantity of gas, principally as condensed ice-like compound of gas and water, called gas hydrates. Since the hydrate stability zone occupies a narrow region of pressure-temperature space, a change in ocean circulation in response to climate warming may lead to a massive release of greenhouse gases to the ocean and atmosphere. Accurate prediction of fluid-rock interactions is essential to constrain the gas migration and help to identify safe storage sites. We therefore need to understand how gas released from hydrates rapidly migrates in offshore sediment stacks and how that relates to the vertical chimneys and pockmarks widely observed on continental shelves.I propose to address these questions employing high-resolution, three-dimensional numerical models that couple multi-phase flow to deformation of the sedimentary porous rocks. Using my strong expertise in high-performance computing, I will implement a three-phase flow formulation accounting for porous compacting sediments, liquid water and compressible gas in efficient, scalable and parallel solvers that use the latest supercomputing technology. I will systematically investigate the relevant parameters that trigger the formation of highly permeable chimneys as a natural outcome of the coupled model. I plan to produce synthetic seismograms of the forward models and to compare them to recent high-resolution 3D geophysical seismic data. The proposed research aims at a quantitative understanding of the physical mechanisms that govern formation of rapidly degassing chimneys in sedimentary rocks by linking high-performance computing to high-resolution geophysical imaging.
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