Geochemical investigation and mineral matrix effect on probable source rock's potentiality during pyrolysis in the Rag-e-Safid oilfield, southwest Iran.

In this study, 45 drilling cuttings of Pabdeh and Kazhdumi formations in Rag-e-Safid oilfield, in southern Dezful Embayment, were analyzed by Rock-Eval instrument. S2 vs. TOC plot revealed that kerogen type in this oilfield predominantly is Type II. Significant S2 adsorption by matrix in Pabdeh (2.5-4 mg HC/gr rock) and Kazhdumi (7-12 mg HC/gr rock) formations is due to low maturation as well as low gas-oil ratio potential factor. Amount of TOC directly influences the mineral matrix effect on hydrocarbon adsorption on Pabdeh Formation. Live organic carbon in Pabdeh and Kazhdumi formations was in the range 0.22-2.29% and 1.7-2.25% by weight, respectively, which showed said formations have fair to excellent potential for petroleum generation. Transformation ratio of kerogen in studied formations was low (0.07-0.15), so these formations have not generated significant amount of petroleum as is supported by low Tmax data. GORP factor in studied formations (0.2-0.5) reveal that their oil generation potential is higher than gas generation potential. Considering to iso TOCoil and TOCgas maps, when Pabdeh Formation was deposited, basin in northwest and southeast was deeper than central part of the oilfield.