Saturate biomarkers and aromatic sulfur compounds in oils and condensates from different source rock lithologies of Kazakhstan, Japan and Russia

Representative petroleums from the seven basins of Kazakhstan, Russia and Japan were analyzed using gas chromatography with dual FID/FPD and GC/MS. The present study has shown that the deviation in relative concentrations of aromatic sulfur compounds in petroleums could be related to the type of source rock. All oil samples were classified into three groups on the basis of the relative abundance of aromatic sulfur compounds, biomarker distribution and lithology of source rock. The first group of oils, derived from carbonate source rocks, is rich in aromatic sulfur compounds such as methylbenzothiophenes (MBT) and methyldibenzothiophenes (MDBT), and poor in dibenzothiophene (DBT) compared to methylated homologs. The second group, derived from siliceous and siliceous-carbonate source rocks, contains various types of benzothiophenes and dibenzothiophenes, including DBT. The third group, originating from argillaceous rocks, has lower concentrations of aromatic sulfur compounds and especially of methylated benzothiophenes.