Impact of velocity correlation and distribution on transport in fractured media: Field evidence and theoretical model - INSU - Institut national des sciences de l'Univers Access content directly
Journal Articles Water Resources Research Year : 2015

Impact of velocity correlation and distribution on transport in fractured media: Field evidence and theoretical model

Abstract

Flow and transport through fractured geologic media often leads to anomalous (non-Fickian) transport behavior, the origin of which remains a matter of debate: whether it arises from variability in frac-ture permeability (velocity distribution), connectedness in the flow paths through fractures (velocity correla-tion), or interaction between fractures and matrix. Here we show that this uncertainty of distribution-versus correlation-controlled transport can be resolved by combining convergent and push-pull tracer tests because flow reversibility is strongly dependent on velocity correlation, whereas late-time scaling of break-through curves is mainly controlled by velocity distribution. We build on this insight, and propose a Lagran-gian statistical model that takes the form of a continuous time random walk (CTRW) with correlated particle velocities. In this framework, velocity distribution and velocity correlation are quantified by a Markov pro-cess of particle transition times that is characterized by a distribution function and a transition probability. Our transport model accurately captures the anomalous behavior in the breakthrough curves for both push-pull and convergent flow geometries, with the same set of parameters. Thus, the proposed correlated CTRW modeling approach provides a simple yet powerful framework for characterizing the impact of veloc-ity distribution and correlation on transport in fractured media.

Domains

Earth Sciences
Fichier principal
Vignette du fichier
kang-et-al-2015.pdf (1.75 Mo) Télécharger le fichier
Origin : Publisher files allowed on an open archive
Loading...

Dates and versions

insu-01119364 , version 1 (23-02-2015)

Identifiers

Cite

Peter K. Kang, Tanguy Le Borgne, Marco Dentz, Olivier Bour, Ruben Juanes. Impact of velocity correlation and distribution on transport in fractured media: Field evidence and theoretical model. Water Resources Research, 2015, 51 (2), pp.940-959. ⟨10.1002/2014WR015799⟩. ⟨insu-01119364⟩
206 View
350 Download

Altmetric

Share

Gmail Facebook X LinkedIn More