Geochemistry Study for Maturity Indeks of Duri and Minas Crude Oil, Riau

The crude oil sample from Duri and Minas oil well (OSM-1) was fractionated into saturated and aromatic hydrocarbon and residu. The saturated hydrocarbon were characterized by using gas chromatografi (GC), whereas aromatic hydrocarbon were determined by gas chromatography-mass spectrometry (GC-MS). The biomarker composisiton indicated that Duri and Minas crude oil was derived from higher plant (terrestrial) with high wax content for Duri and lower for Minas, it also showed that Minas crude oil was deposit from difftrent deposional environment conditions. The thermal maturity of Minas crude oil was determined by maturity parameters from aromatic hydrocarbons such as methylpenantrene index (MPI) and vitrinite reflectance equivalent (VRE). The result indicated that the crude oil from Minas oil well (OSM-1) has value of MPI-1, MPI-2, MPI-3 and VRE of 0.82, 0.89, 1.02 and 0.89% respectively. The showed that Minas Crude oil has haigh level of maturity.