Clay Stability in Liquids: Effect of Aluminum Oxide and Zinc Oxide Nanoparticles

Abstract

In the petroleum industry, clay is a major composition of water and oil based drilling fluids, but other additives are introduced to enhance rheological properties. One of such additives includes aluminum oxide (Al₂O₃) and zinc oxide (ZnO) nanoparticles which have been reported to improve drilling fluid characteristics. However, the effect of these nanoparticles on the stability of clays in different liquid mediums needs to be investigated.
In this work, the effect of Al₂O₃ and ZnO nanoparticles on the stability of clays in distilled water, brine of 30g/l salinity, ethanol and diesel is studied in quiescent column of liquids in the absence and presence of crude oil. Results show that Al₂O₃ and ZnO nanoparticles enhance clay instability in liquids; in fact, clays are more stable in liquids in the absence of these two kinds of nanoparticles than in their presence. In order not to enhance clay instability in liquids, it is suggested that Al₂O₃ and ZnO nanoparticles be used cautiously and possibly with other kinds of nanoparticles that promote particle stability in fluids. Further studies in determining the effect of organic matters on clay stability is encouraged since observations are inconsistent especially in the references cases where nanoparticles are absent.