STRUCTURAL-ANALYSIS OF WEATHERED OIL FROM KUWAITS ENVIRONMENT

An average molecular structural analysis was applied to the oils extra cted from a sediment at Shuaiba in June 1995, and from soils at Jaidan in November 1993 and November 1994, Sabriya in November 1993 and Nove mber 1994, and the heavy fraction (boiling point >340 degrees C) of Ku wait crude oil. Using the results of elemental analysis, average molec ular weight measurement, H-1 and C-13 NMR analyses, an average molecul ar structure was estimated on the saturate-free fraction of each sampl e, and the variation of the average molecular structures was discussed . All average molecules of saturate-free fractions included only one f used ring system, 35-42 total carbons, 52-64 hydrogens, 10-14 aromatic carbons, and 1 sulfur atom, which included benzothiophene or dibenzot hiophene type structure. The oil samples from the soils included 1-2 o xygen atoms. The oil from Sabriya in November 1994 had more naphthenic rings than any other oils, indicating its further degradation. From t he comparison of the average molecular structural parameters, it becam e clear that oils in soils degraded by condensation, aromatization, cy clization, and oxidation reactions. In contrast with those oils, oil i n sediment degraded by the formation of naphthenic rings and the decre ase in aliphatic chains, which suggested some effects of microorganism s. (C) 1998 Elsevier Science Ltd.