METHYLATED DICYCLIC AND TRICYCLIC AROMATIC-HYDROCARBONS IN CRUDE OILS FROM THE HANDIL FIELD, INDONESIA

Twenty-three C1- to C3-napthalenes and seventeen C1- and C2-phenanthrenes have been determined in six crude oils from the Handil field. Tentative identifications of individual C2-phenanthrene isomers based on gas chromatographic-mass spectrometric (GC-MS) analysis could be proved by combined use of high performance liquid chromatography (HPLC) and high resolution spectrofluorimetry in an n-alkane matrix at 15 K (Shpol'skii effect). Based on quantitative isomer distributions of alkylnapthalenes and alkylphenanthrenes and the maturity parameters derived therefrom, consistently high maturities of Handil oils assumed in earlier studies are confirmed. The Methylphenanthrene Index (MPI 1) indicates an origin of the oils from source rocks having a present depth of more than 3400 m, which is deeper than previously assumed. Minor discrepancies in the aromatic distributions, possibly due to volatility fractionation, apparently are unrelated to migration distances. © 1990.