Source rock potential, crude oil characteristics and oil-to-source rock correlation in a Central Paratethys sub-basin, the Hungarian Palaeogene Basin (Pannonian basin)

Eocene and Lower Oligocene rocks are potential source for crude oil accumulations in the Hungarian Palaeogene Basin. To enhance understanding of hydrocarbon system, this study (i) assesses petroleum formations, (ii) characterises rock facies accumulated oils, (iii) provides an oil-to-source correlation. Rock-Eval data samples from three boreholes (W–1, W–9 W–12) show that most formations mature at depths exceeding 2.1–2.5 km. The coal-bearing Kosd Formation includes good to excellent gas- (and oil-) prone rocks. overlying Buda Marl is typically organic matter-lean but contains oil-prone with up 2.3 wt% TOC a fair borehole W–9. Tard Clay W–12 reaches 1.9 shows HI values 440 mg HC/g TOC, characterising deposits as Based on low contents, Kiscell not considered rock. Molecular parameters 12 indicate shaly deposited marine/brackish environment. Salinity stratification, causing development oxygen-depleted conditions, likely. matter dominated by aquatic biomass, including algae, dinoflagellates chemoautotrophic bacteria. Minor angiosperm-dominated was transported into basin shoreline. Specific V-shaped compound-specific carbon isotope patterns n-alkanes observed oils extracts prove dominant differences between biomarker ratios related vertical lateral variations within Formation. slightly more than W–12.