The weathering properties of four unique crude oils from Australia

This paper reports on the results of weathering studies conducted on four light crude oils from production platforms on the northwest shelf of Australia. The laboratory weathering included both evaporative weathering and emulsification studies. The fresh oils and their topped residues were subjected to a battery of physical and chemical characterization analyses. Detailed analyses were performed for n-alkanes by GC/FID and for mono- and polycyclic aromatic hydrocarbons and phenols by GC/MS. The water-in-oil emulsion formation properties of these oils and their topped residues were investigated at two environmentally significant temperatures (13 and 20°C). The results of the analyses indicate that these oils are very different compositionally and have a wide range of physical and chemical properties. The emulsification properties of these oils and their weathered residues ranged from oils that have very rapid water uptake to oils having no water uptake. Unexpectedly, the very waxy oils had very little water uptake and did not form stable water-in-oil emulsions.