Characterizing Pore‐Scale Configuration of Organic Immiscible Liquid in Multiphase Systems With Synchrotron X‐Ray Microtomography

Abstract

The objective of this study was to examine the pore‐scale distribution and morphology of organic immiscible liquid in natural porous media containing three immiscible fluids. High‐resolution, three‐dimensional images of an organic liquid (tetrachloroethene) in both three‐phase (water–air–organic liquid) and two‐phase (water–organic liquid) systems were obtained using synchrotron X‐ray microtomography. These data were used to quantitatively characterize the morphology of the organic liquid residing within columns packed with one of three natural, sandy porous media. Organic‐liquid blobs varied greatly in both size and shape, ranging from small, single spheres (≥0.03 mm in diameter) to large, amorphous ganglia with mean lengths of 4 to 5 mm. Singlets comprised the greatest number of blobs, whereas the large ganglia, while much fewer in number, comprised the majority of the organic‐liquid surface area and volume. A significant portion of the organic liquid in the three‐phase systems was observed to exist as lenses and films in contact with air. These features were not observed in the two‐phase water–organic liquid systems. The median of the blob‐frequency distributions was smaller and the variance larger for the three‐phase systems. In addition, the global specific surface areas of the organic liquid were greater for the three‐phase systems. These differences are attributed to the presence of the organic‐liquid lenses and films for the three‐phase systems.