On Monday, December 16, 2019 Atta-ul Monem Ayaz will defend his thesis titled “Experimental and numerical investigation of cluster morphologies and dynamic during biphasic flow in porous media”. The thesis is a joint Phd thesis between the University of Strasbourg and the University of Oslo through a Cotutelle-agreement. The defense will take place at the University of Strasbourg, France.
Professor Renaud Toussaint, University of Strasbourg and PoreLab UiO, and Gerhard Schafer, University of Strasbourg, are his supervisors at the University of Strasbourg and Knut Jørgen Måløy is his supervisor at PoreLab University of Oslo.
Porous materials widely exist around us and play a role in many aspects of our life. Natural substances such as rocks and soil can often be considered to be porous materials. It is thanks to their porosity that soil allows for precipitation to migrate from the surface to ground water aquifers. Similarly in rocks such as calcite the connected pores set up pathways for mineral water to percolate through stone, allowing for changes of the chemical composition over long time scales. The work presented in this thesis is concerned with improving our understanding of the underlying mechanisms by which fluids are transported in porous media and how dense suspensions transport through a confining geometry . An improved understanding of such processes promises economical benefits such as enhanced oil recovery, and great environmental rewards, among other in terms of CO2 sequestration in sub-sea reservoirs and mapping and controlling of migrating ground water contaminants. We study mechanisms governing fluid-displacement during drainage. We show that by combining a detailed description of the pore-scale with parameters acting on the system scale, we are able to find a pressure-saturation relation which allows for upscaling of the system. Furthermore we will increase our understanding of mechanisms by which drainage occurs such as Haines jumps and snap-off. We will look at the case of deformable porous media in a cylindrical confinement within the capillary length, and study how grain-grain interactions and interactions with the confining geometry give rise to the emergence of previously unexplored patterns.