oa Origin and Maturity Assessment of Oils and Source Rocks from the Eastern Part of Drava Depression, Croatia

In the present study, six crude oils from the eastern part of the Drava depression (Benicanci, Bokšic, Kucanci, Crnac, Števkovica and Obod) were investigated to define origin, depositional environment and thermal maturity. The study utilized bulk parameters, gas chromatography (GC) of “whole” oil and gas chromatography-mass spectrometry (GC-MS) of biomarkers and phenanthrene derivatives.

Although crude oils from the eastern part of the Drava depression have different bulk properties (e.g. API gravity, sulphur content, pour point), according to the biomarker “fingerprints” all analysed oils have the common origin and were generated from source rocks containing a mainly marine organic matter with same input of terrestrial components.

Biomarkers indicate the similarity in the origin and maturity of the crude oils from the eastern part of the Drava depression with the determined source rocks in this area.