Correlative geochemical study of crude oils from southeastern and southern parts of the Pannonian Basin

Abstract

Several crude oils from the southeastern Yugoslav part of the Pannonian Basin are correlated for the first time on the basis of many bulk and specific parameters. The investigations involved 15 oils from oil-gas fields A and B and oil field C from the Banat depression and oil field D from South Bačka depression, and four oils from recently discovered oil shows E (the Kostolac depression). On the basis of structural group analysis and other bulk parameters such as API gravity, contents of asphaltenes and sulfur, as well as content of n-alkanes and pristane to phytane ratio, the examined oils are classified into four groups. However, the distributions and relative abundances of n-alkanes, isoprenoids (C19, C20), steranes, tricyclic terpanes and pentacyclic triterpanes, obtained by capillary GC and computerized GC-MS analysis, suggest classification of the examined oils into only two genetic types: A-D and E1-E4. The oils are of relatively high maturity. They are not biodegraded, except for both oils from field D and the oil A9. © 1987.