Study of Stratigraphy, Biostratigraphy, Microfacies, Diagenesis, Sequence Stratigraphy and Reservoir Potential of the Fahliyan Formation in the Marun Oil Field, Zagros Basin, Southwest Iran

Fahliyan Carbonate Formation with the age of Neocomian (Lower Cretaceous) is a main reservoir of Khami Group and is extended in whole Zagros Basin. The equivalent formation of Fahliyan Formation in Saudi Arabia, Bahrain and Qatar is Yamama Formation and in Kuwait from older to earlier; Makhul, Minaghish and Ratawi Formations (Setudenia, 1978). Considering Fahliyan performance as a high-quality reservoir and Marun Oil Field as one of the top biggest oil fields in Dezful Embayment, southwest Iran, a detailed study looked quite necessary in this area. This research was mainly done based on petrographic methods. Moreover, well logs were used as a subsidiary tool to assess the reservoir potential of microfacies. After recognition of microfacies and evaluation of lateral and vertical variations (using Walter’s law) depositional model of Fahliyan Formation was proposed. At the final stage, compartments with more reservoir potential were proposed. Generally speaking, the main tasks done through this study are: Study of microfossils (benthic foraminifera and algae), Relative age determination of Fahliyan Formation (based on age of microfossils), Study of different kinds of microfacies, Study of depositional environment, Study of diagenetic processes and Assessment of microfacies with reservoir potential using thin sections and well logs.