Sedimentary Environment, Diagenesis of Sarvak Formation in the Zagros Basin, Iran

In this research, we investigated the environment of a carbonate ramp formation called Pabdeh from the Paleocene to the end of the Oligocene, a part of carbonate reservoirs in the Zagros basin. For this purpose coring samples and cutting were employed from every two meters of the desired formation. Petrographical studies of ۱۵۹ thin sections identified four lithofacies: (i) Oligosteginid-Echinoid Wackestone and Packstone (Microfacies ۱) (ii) Oligosteginid Wackestone and Packstone (microfacies ۲) (iii) Rudist-Echinoderm Packstone and Grainstone (Microfacies ۳), and (iv) Benthonic Foraminiferal (Calcareous) Mudstone (microfacies ۴). The results of the petrographic study showed that the Sarvak Formation was deposited in a homoclinal carbonate-ramp depositional environment. Additionally, this study showed that the Sarvak Formation is subjected to various diagenetic processes shaping its reservoir characteristics. These processes include bladed calcite crystals, blocky cement, sparry calcite, rimed calcite overgrowths, and fibrous isopachous formations occurring at different stages and environments. Also, Fracturing significantly influences reservoir quality by enhancing permeability and connecting pore spaces, particularly observed in carbonate and siliciclastic rocks of the Sarvak Formation. Understanding these diagenetic processes is crucial for reservoir characterization and hydrocarbon exploration in the Sarvak Formation.

کلیدواژه ها:

Sarvak Formation ، Diagenesis ، Sedimentary Environment