Isotopic and molecular characteristics of Miocene-reservoired oils of the Kutei Basin, Indonesia

Although this chemical distinction between Onshore/Shelf and Slope oils is likely to be source-defined, migration-induced compositional changes also appear to play a role. Molecular maturity ratios are inversely proportional to the relative concentrations of various oleanenes and bicadinenes in this oil set, and suggest that migration-contamination has compromised maturity assessment of these oils.