Details zur Publikation |
| Kategorie | Textpublikation |
| Referenztyp | Zeitschriften |
| DOI | 10.1002/2015wr017852 |
| Titel (primär) | The impact of pore structure and surface roughness on capillary trapping for 2-D and 3-D porous media: comparison with percolation theory |
| Autor | Geistlinger, H.; Ataei-Dadavi, I.; Mohammadian, S.; Vogel, H.-J. |
| Quelle | Water Resources Research |
| Erscheinungsjahr | 2015 |
| Department | BOPHY |
| Band/Volume | 51 |
| Heft | 11 |
| Seite von | 9094 |
| Seite bis | 9111 |
| Sprache | englisch |
| UFZ Querschnittsthemen | RU1 |
| Abstract | We study the impact of pore structure and surface roughness on capillary trapping of nonwetting gas phase during imbibition with water for capillary numbers between 10−7 and 5 × 10−5, within glass beads, natural sands, glass beads monolayers, and 2-D micromodels. The materials exhibit different roughness of the pore-solid interface. We found that glass beads and natural sands, which exhibit nearly the same grain size distribution, pore size distribution, and connectivity, showed a significant difference of the trapped gas phase of about 15%. This difference can be explained by the microstructure of the pore-solid interface. Based on the visualization of the trapping dynamics within glass beads monolayers and 2-D micromodels, we could show that bypass trapping controls the trapping process in glass beads monolayers, while snap-off trapping controls the trapping process in 2-D micromodels. We conclude that these different trapping processes are the reason for the different trapping efficiency, when comparing glass beads packs with natural sand packs. Moreover, for small capillary numbers of 10−6, we found that the cluster size distribution of trapped gas clusters of all 2-D and 3-D porous media can be described by a universal power law behavior predicted from percolation theory. This cannot be expected a priori for 2-D porous media, because bicontinuity of the two bulk phases is violated. Obviously, bicontinuity holds for the thin-film water phase and the bulk gas phase. The snap-off trapping process leads to ordinary bond percolation in front of the advancing bulk water phase and is the reason for the observed universal power law behavior in 2-D micromodels with rough surfaces. |
| dauerhafte UFZ-Verlinkung | https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=16933 |
| Geistlinger, H., Ataei-Dadavi, I., Mohammadian, S., Vogel, H.-J. (2015): The impact of pore structure and surface roughness on capillary trapping for 2-D and 3-D porous media: comparison with percolation theory Water Resour. Res. 51 (11), 9094 - 9111 10.1002/2015wr017852 |
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