Modeling solute diffusion in the presence of pore-scale heterogeneity: method development and an application to the Culebra dolomite member of the Rustler Formation, New Mexico, USA.
J Contam Hydrol
; 48(3-4): 253-76, 2001 Apr.
Article
em En
| MEDLINE
| ID: mdl-11285934
ABSTRACT
Previous studies have revealed the presence of pore-scale variability in diffusivity in the Culebra (dolomite) member of the Rustler Formation, NM. In this study, eight laboratory-scale diffusion experiments on five Culebra samples were analyzed using a methodology for modeling solute diffusion through porous media in the presence of multiple matrix diffusivities, Dp. A lognormal distribution of Dp is assumed within each of the lab samples. The estimated standard deviation (sigma d) of ln(Dp) within each sample ranges from 0 to 1, with most values lying between 0.5 and 1. The variability over all samples leads to a combined sigma d in the range of 1.0-1.2, which is consistent with the distribution of independently determined formation factor measurements for similar Culebra samples. A comparison of our estimation results to other rock properties suggests that, at the lab-scale, the geometric mean of Dp increases with bulk porosity and the quantity of macroscopic features such as vugs and fractures. However, sigma d appears to be determined by variability within such macroscopic features and/or by micropore-scale heterogeneity. In addition, comparison of these experiments to those at larger spatial scales suggests that increasing sample volume results in an increase in sigma d.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Carbonato de Cálcio
/
Geologia
/
Magnésio
/
Modelos Teóricos
Tipo de estudo:
Prognostic_studies
País/Região como assunto:
America do norte
/
Mexico
Idioma:
En
Revista:
J Contam Hydrol
Assunto da revista:
TOXICOLOGIA
Ano de publicação:
2001
Tipo de documento:
Article
País de afiliação:
Estados Unidos