Skip to Main content Skip to Navigation
Journal articles

Non-Fickian dispersion in porous media : 2. Model validation from measurements at different scales

Abstract : We aim at testing and validating a mobile-immobile mass transfer model from a set of single-well injection withdrawal tracer tests in a heterogeneous porous aquifer. By varying the duration of the injection phase, different volumes of aquifer are investigated by the tracer. Hence, we focus the transport model validation not only on reproducing a single breakthrough curve (BTC) but also on the model's capacity to predict the amount of mixing as a function of the volume visited by the tracer. All the BTCs are strongly asymmetric, as expected when dispersion is controlled by diffusive mass transfers between the mobile water and the immobile water part of the porosity. However, the BTC cannot be modeled by a conventional mobile-immobile mass transfer model with a simple power law memory function. To account for that, we implement a continuous time random walk model in which the transition time distribution y (t), which is related to the excursion time probability of the tracer in the immobile domain, is a dual-slope power law distribution. The model best fits the BTC data set with a transitional regime controlled by y(t) t2 and an asymptotic regime characteristic of the conventional double-porosity model with y(t) t1.5 . This work emphasizes that high-resolution concentration measurement and multiple-scale tracer tests are required for assessing solute dispersion models in heterogeneous reservoirs and for subsequently obtaining reliable predictions.
Document type :
Journal articles
Complete list of metadatas

Cited literature [29 references]  Display  Hide  Download

https://hal-insu.archives-ouvertes.fr/insu-00373698
Contributor : Isabelle Dubigeon <>
Submitted on : Wednesday, June 29, 2016 - 10:50:36 AM
Last modification on : Friday, April 5, 2019 - 8:14:53 PM
Long-term archiving on: : Friday, September 30, 2016 - 10:59:25 AM

File

Borgne_et_al-2008-Water_Resour...
Publisher files allowed on an open archive

Identifiers

Citation

Tanguy Le Borgne, Philippe Gouze. Non-Fickian dispersion in porous media : 2. Model validation from measurements at different scales. Water Resources Research, American Geophysical Union, 2008, 44, pp.W06427. ⟨10.1029/2007WR006279⟩. ⟨insu-00373698⟩

Share

Metrics

Record views

377

Files downloads

303