Effect of fracture characteristics on DNAPL-water flow in rock fractures

W.M.S.B. Weerakone, R.C.K. Wong

In the proceedings of: GEO2011: 64th Canadian Geotechnical Conference, 14th Pan-American Conference on Soil Mechanics and Geotechnical Engineering, 5th Pan-American Conference on Teaching and Learning of Geotechnical Engineering

Session: Geoenvironmental Engineering

ABSTRACT: This study investigates the influence of fracture properties on Dense Non-Aqueous Phase Liquids (DNAPL)-water flow in rock fractures. The aperture distributions of fractures in sandstone and shale specimens of Alberta Paskapoo Formation were obtained from X-ray Computed Tomography (CT) technique. Then, geostatistical parameters of each aperture distribution were estimated, and isotropic or anisotropic nature of the aperture distributions were identified. Equiprobable aperture distributions were generated from stochastic simulation to observe the effect of anisotropy of aperture distribution on DNAPL migration parameters. First, pore-scale single-phase flow was simulated in generated fractures using classical Local Cubic Low (LCL) approach. Then, DNAPL-water two-phase flow process was simulated in each generated fracture by utilizing the invasion percolation approach. The effects of anisotropy of aperture distributions on the main flow parameters, the fracture permeability and capillary pressuresaturation relationship, were determined from the results of the simulated flow processes.

RÉSUMÉ: Cette étude a examiné l'influence des propriétés des fractures sur les phases liquides denses non-aqueux (DNAPL) - particulièrement l'écoulement le long de fractures de roche. La distribution des ouverture des fractures dans des spécimens de grès et de schiste de la formation Paskapoo en Alberta ont été examinés utilisant la technique de la tomographie rayon X (CT). Puis, des paramètres geostatistiques de chacune des ouvertures ont été estimés pour en identifier la nature isotrope ou anisotrope. Des distributions d'ouverture d'équiprobable ont été produites pour observer l'effet de l'anisotropie sur les paramètres de migration du DNAPL. Premièrement, l'écoulement monophasé dans les fractdu DNAPL a été simulé dans chaque fracture produite en utilisant l'approche de percolation d'invasion. Les effets de l'anisotropie des distributions d'ouverture sur les paramètres principaux d'écoulement, la perméabilité de la fracture et rapport de pression-saturation capillaire, ont été déterminés à partir des résultats de simulation.

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Cite this article:
W.M.S.B. Weerakone; R.C.K. Wong (2011) Effect of fracture characteristics on DNAPL-water flow in rock fractures in GEO2011. Ottawa, Ontario: Canadian Geotechnical Society.

@article{GEO11Paper799,author = W.M.S.B. Weerakone; R.C.K. Wong ,title = Effect of fracture characteristics on DNAPL-water flow in rock fractures,year = 2011}