Hydrocarbon generation potential of the Kazhdumi Formation in Tang-E Maghar and Perchestan sections compared to the other oil fields in the Zagros Basin

Investigating the hydrocarbon generation potential of the Kazhdumi Formation, as the most important oil source rock in the Zagros sedimentary basin, is of great importance. The expansion of the Kazhdumi Formation in the Zagros Basin has been associated with differences in sedimentation depth of the basin leading to varieties in sedimentary facies and the organic matter preservations. Five black shale samples from Perchestan and Tang-E Maghar sections were selected for analysis by Rock-Eval pyrolysis, and were compared to the data of 25 Kazhdumi samples from different oil fields of Nowrouz, Soroush, Azadegan and Chah-E Binak, previously studied in the Zagros Basin. Additionally, sedimentary environment and depositional conditions were investigated. Sedimentary and geochemical evidences indicate a dominant condition of high organic content shale deposition in the reducing to semi-oxidative environments. The values obtained for total organic carbon (TOC) ranged from 1.2 to 6.9%. Examination of the thermal maturity of the samples showed a wide range from the immature range to the middle oil window, which are often in the range of type II and III kerogens. Finally, the drawing of the TOC vs. S2 diagram represents the higher hydrocarbon generation potential of the Kazhdumi Formation in the Tang-E Magher section, and the TOC vs. HI diagram shows the greater oil generation in the Soroush field, compared to the other studied areas.