Effect of fracture aperture variations on the dispersion of contaminants

Abstract

The observed transport of a nonsorbing solute in a naturally fractured rock was characterized at very high resolution using computed tomography scanning to determine the fracture aperture distribution. The observed breakthrough curve of the solute at various flow rates were compared with the predicted breakthrough curve using the fracture's geostatistics and small perturbation analysis, as well as direct numerical simulation of flow through the fracture using the measured fracture aperture distribution. The experimentally determined fracture transmissivity and dispersivity were within the factor of 2 of those predicted using either the small perturbation method or explicit numerical modeling of breakthrough.