Geochemical pyrolysis, petrographical analysis and burial history reconstructions of the Kazhdumi Formation in the Hendijan and Soroosh oil fields, northwestern Persian Gulf

Abstract

The Kazhdumi Formation is one of the most important source units throughout the Persian Gulf and surrounded areas that mainly formed from dark, organic rich shales and marls. In this study, source characteristics of the Kazhdumi successions in the Hendijan and Soroosh oilfields (northwestern Persian Gulf) are evaluated using the Rock-Eval pyrolysis, vitrinite reflectance analysis and one-dimensional thermal modeling. The Rock-Eval data suggest good to very good and poor to fair hydrocarbon potentials for the studied formation in the Hendijan and Soroosh oil fields, respectively. In addition, pyrolyzed data reveal that the successions mainly contain kerogen type II in the Hendijan and kerogen type III in the Soroosh oil fields. Also the Tmax values and vitrinite reflectance measurements show that the Kazhdumi Formation has reached to the oil generation phase in the Hendijan, whereas this formation is immature in the Soroosh Field. Moreover, reconstructions of thermal history exhibit that variations in maturity are linked to the Kazhdumi burial depth and the values of basin heat flow. Eventually, the combination of results indicate that the Kazhdumi hydrocarbon generation in northwestern Persian Gulf increase considerably towards the Dezful Embayment.