Observations of the impact of rock heterogeneity on solute spreading and mixing
File(s)
Accepted version
Author(s)
Boon, M
Bijeljic, B
Krevor, S
Type
Journal Article
Abstract
Rock heterogeneity plays an important role in solute spreading and mixing in hydrogeologic systems. Few observations, however, have been made that can spatially resolve these processes in 3-D, in consolidated rocks. We make observations of the spatially resolved steady state concentration of a sodium iodide solute while flowing brine through cylindrical rock cores using X-ray CT imaging. Three rocks with an increasing level of heterogeneity are chosen: a Berea sandstone, a Ketton carbonate, and an Indiana carbonate. The impact of heterogeneity on solute transport is analyzed by: (1) quantifying spreading and mixing using metrics such as the transverse dispersion coefficient, the dilution index, the reactor ratio, and the scalar dissipation rate and (2) visualizing and analyzing flow structures such as meandering, flow-focusing, and flow-splitting using isoconcentration contour maps. The transverse dispersion coefficient, Dt, and the variation in Dt throughout the rock core, increases with Peclét number (Pe) and rock heterogeneity. The reactor ratio indicates that mixing is Fickian for the Berea sandstone and Ketton carbonate, but diverges for the Indiana carbonate. The temporal evolution of the scalar dissipation rate, a measure of the mixing rate, remains close to that of Fickian mixing for the Berea and Ketton rocks but not for the Indiana. Heterogeneous rock features are observed to cause meandering, focusing, or splitting of the plume depending on Pe.
Date Issued
2017-06-08
Date Acceptance
2017-05-14
Citation
Water Resources Research, 2017, 53 (6), pp.4624-4642
ISSN
0043-1397
Publisher
Wiley-Blackwell
Start Page
4624
End Page
4642
Journal / Book Title
Water Resources Research
Volume
53
Issue
6
Copyright Statement
© 2017. American Geophysical Union. All Rights Reserved.
Sponsor
Qatar Shell Research and Technology Center QSTP LLC
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000405997000008&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Grant Number
490000724
Subjects
Science & Technology
Life Sciences & Biomedicine
Physical Sciences
Environmental Sciences
Limnology
Water Resources
Environmental Sciences & Ecology
Marine & Freshwater Biology
TRANSVERSE DISPERSION COEFFICIENTS
MULTICOMPONENT REACTIVE TRANSPORT
POROUS-MEDIA
LATERAL DISPERSION
SCALAR DISSIPATION
PACKED-BEDS
DILUTION
FLOW
VISUALIZATION
PERMEABILITY
Publication Status
Published