Details zur Publikation

Kategorie Textpublikation
Referenztyp Zeitschriften
DOI 10.1002/2015WR018254
Titel (primär) Pore-scale displacement mechanisms as a source of hysteresis for two-phase flow in porous media
Autor Schlüter, S.; Berg, S.; Rücker, M.; Armstrong, R.T.; Vogel, H.-J.; Hilfer, R.; Wildenschild, D.
Quelle Water Resources Research
Erscheinungsjahr 2016
Department BOPHY
Band/Volume 52
Heft 3
Seite von 2194
Seite bis 2205
Sprache englisch
Keywords hydrology; oil recovery; multiphase flow; integral geometry
UFZ Querschnittsthemen RU1
Abstract The macroscopic description of the hysteretic behavior of two-phase flow in porous media remains a challenge. It is not obvious how to represent the underlying pore-scale processes at the Darcy-scale in a consistent way. Darcy-scale thermodynamic models do not completely eliminate hysteresis and our findings indicate that the shape of displacement fronts is an additional source of hysteresis that has not been considered before. This is a shortcoming because effective process behavior such as trapping efficiency of CO2 or oil production during water flooding are directly linked to pore-scale displacement mechanisms with very different front shape such as capillary fingering, flat frontal displacement, or cluster growth. Here we introduce fluid topology, expressed by the Euler characteristic of the nonwetting phase (χn), as a shape measure of displacement fronts. Using two high-quality data sets obtained by fast X-ray tomography, we show that χn is hysteretic between drainage and imbibition and characteristic for the underlying displacement pattern. In a more physical sense, the Euler characteristic can be interpreted as a parameter describing local fluid connectedness. It may provide the closing link between a topological characterization and macroscopic formulations of two-phase immiscible displacement in porous rock. Since fast X-ray tomography is currently becoming a mature technique, we expect a significant growth in high-quality data sets of real time fluid displacement processes in the future. The novel measures of fluid topology presented here have the potential to become standard metrics needed to fully explore them.
dauerhafte UFZ-Verlinkung https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=17479
Schlüter, S., Berg, S., Rücker, M., Armstrong, R.T., Vogel, H.-J., Hilfer, R., Wildenschild, D. (2016):
Pore-scale displacement mechanisms as a source of hysteresis for two-phase flow in porous media
Water Resour. Res. 52 (3), 2194 - 2205 10.1002/2015WR018254