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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Modellierung und experimenteller Nachweis von Zusammenhängen zwischen Parametern des Vernadelns, der Faseroberfläche und des Porenvolumens von dreidimensionalen Vliesstoffen

Schimanz, Barbara. Unknown Date (has links) (PDF)
Techn. Universiẗat, Diss., 2005--Chemnitz.
2

Einfluss der Pedogenese auf die räumliche Porengeometrie und damit verbundene hydraulische Transporteigenschaften in Böden aus Braunkohlenaschen /

Kastler, Michael. January 2006 (has links)
Universiẗat, Landw. Fak., Diss.--Halle, 2005.
3

The influence of physico-chemical surface properties and morphological and topological pore space properties on trapping (CCS) and recovery efficiency (EOR): a micromodel visualization study

Golmohammadi, Saeed 26 October 2023 (has links)
We theoretically and experimentally investigate the impact of pore space structure, wettability, and surface roughness on the displacement front, trapping, and sweeping efficiency at low capillary numbers. The microstructure of (i) 2D geologically-realistic media (2D natural sand and sandstone), (ii) a topological 3D-2D-transformation (2D sand analog), and (iii) geometrically representative media (Delaunay Triangulation) were studied over a wide range of wettability from water-wet to oil-wet systems provided by using various fluid-pairs. We observed the transition (compact to fractal) in the displacement front caused by local instabilities identified by Cieplak and Robbins. The trapping efficiency of 2D natural microstructures showed a non-monotonous dependency on wettability, whereas a crossover from no trapping to maximal trapping was observed in 2D patterns of circular grains. For the first time, we compared identical experimental microstructures with simulation, capturing the key elements of the invasion process. We demonstrated that corner flows occur particularly in low-porosity media, where the smaller grain-grain distance hindered the corner-flow bridging. These insights could improve the CO2 geological storage and Enhanced Oil Recovery processes.
4

Investigations on the influence of pore structure and wettability on multiphase flow in porous medium using x-ray computed tomography: Application to underground CO2 storage and EOR

Zulfiqar, Bilal 28 May 2024 (has links)
Capillary trapping plays a central role in the geological storage of CO2, oil recovery, and water soil infiltration. The key aim of this study is to investigate the impact of surface properties (wettability, roughness, heterogeneous mineral composition) on the dynamics of quasi-static fluid displacement process and capillary trapping efficiency in porous medium. We concluded that for homogeneous wet smooth glass beads surfaces, a transition in fluid displacement pattern occurs from a compact (for θ < 90°; imbibition process) to a fractal front-pattern (for θ > 90°; drainage process) leading to a crossover in capillary trapping efficiency from zero to maximum. The impact of surface roughness on capillary trapping efficiency was also studied, and an opposite trends in terms of wettability dependency was observed. Rough natural sands surfaces depicts a non-monotonous wettability dependency, i.e. a transition from maximal trapping (for θ < 90°) to no-trapping occurs (at θ = 90°), followed by an increase to medium trapping (for θ > 90°). For a fractional-wet media, the percolating cluster of hydrophobic sediments (connected hydrophobic pathways) characterize the fluid displacement pattern and trapping efficiency.

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