Modeling of dense nonaqueous phase liquid entrapment and dissolution in variable aperture fractures
2009 (English)In: Proceedings of TOUGH2 Symposium 2009, Lawrence Berkeley National Laboratory, Berkeley, California, 2009Conference paper (Refereed)
This study investigates dense non-aqueous phase liquid (DNAPL) entrapment and dissolution in single, variable-aperture fractures. Log-normally distributed aperture fields with local permeabilities following the cubic law are assumed. Special attention is given to the capillary pressure-liquid saturation function to account for the specific drainage and wetting characteristics of fractures. DNAPL migration and immobilization is modeled by using the iTOUGH2/T2VOC models, and dissolution is simulated using the TMVOC model. Multiple realizations with different sets of aperture statistics and fracture inclination angles are analyzed.
The results suggest that the entrapment geometry of DNAPL in a heterogeneous fracture is highly sensitive to the aperture statistics. Larger correlation length or standard deviation produces a wider range of total entrapped DNAPL volume. Modeling of different fracture inclination angles reveals that gravity force plays an important role as well. Subsequent dissolution modeling shows that mass transfer will also be strongly influenced by the different DNAPL entrapment architectures corresponding to the different aperture correlation lengths and standard deviations.
Place, publisher, year, edition, pages
Lawrence Berkeley National Laboratory, Berkeley, California, 2009.
Oceanography, Hydrology, Water Resources Earth and Related Environmental Sciences
IdentifiersURN: urn:nbn:se:uu:diva-120367OAI: oai:DiVA.org:uu-120367DiVA: diva2:303222
TOUGH2 Symposium 2009