Influence of Porous Medium Characteristics and Measurement Scale on Pore-ScaleDistributions of Residual Nonaqueous-Phase Liquids. (Reannouncement with New Availability Information)

摘要

A series of experiments was performed to characterize the morphologicdistribution of nonaqueous-phase liquids (NAPL's) at residual saturation as a function of porous medium size. Morphologic characterization of NAPL distributions was accomplished using a novel in situ polymerization technique. The porous medium consisted of glass beads. Blob length, volume and shape characteristics were determined for each experiment, and pore size distributions were determined through capillary pressure-saturation experiments. Both the blob length and pore size distributions were fitted to a van Genuchten function. Both blob length and pressure-saturation data could be scaled with the same averaged porous medium characteristics. The blob length distributions were found to be wider than the pore size distributions. Estimates of representative elementary volumes (REV's) were generated from statistical analysis using a van Genuchten cumulative frequency distribution function for blob length and an empirical function for blob volume as a function of blob length. Simulations were also performed using a Monte Carlo method. The size of the REV needed for a given level of prediction of the residual saturation level was found to increase as a function of mean particle volume for the similar media used in this study. Extrapolation of the analysis suggests the REV will increase as uniformity decreases. Nonaqueous-Phase Liquids(NAPL), Representative Elementary Volumes(REV).