1D and 3D Models of the Northwest Persian Gulf’s Permo-Triassic Petroleum System

This study develops one dimensional (1D) and three dimensional (3D) basin models to evaluate the evolution of the Paleozoic petroleum system surrounding the studied gas field in the northwest Persian Gulf (i.e., offshore Iran). The system features Permo–Triassic reservoirs in the Kangan and Dalan formations (i.e., primarily dolomitic limestone, dolomite, and limestone), sourced from the Early Silurian organic-rich shales of the Sarchahan Formation and sealed by the Triassic shales and anhydrites of the Dashtak Formation. The reservoir trap is a prominent anticline associated with a Hormuz salt diapir. Using well data, seismic interpretations, and geochemical parameters, a 1D petroleum system model (PSM) was developed at a field well. It reconstructed the burial history, thermal maturity (calibrated with vitrinite reflectance), and timing of hydrocarbon generation, expulsion, migration, and entrapment. The 1D model’s results indicate that the salt-dome structure was formed by ∼200 Ma and continued growing, with Sarchahan thermal maturation initiating ∼250–300 Ma and peak hydrocarbon generation, expulsion, and migration occurring ∼150–50 Ma. The 3D PSM extends this analysis across the gas field by incorporating seismic-derived thickness variations to map migration pathways, accumulation zones, and fault influences on entrapment. The combined models highlight the role of salt tectonics, Hercynian and Zagros orogenies, and depositional sequences in system dynamics, identifying unexplored prospects in the deeper Kangan and Dalan sections. These insights reduce exploration risks and guide prospect selection in the salt-influenced basins of the Mesopotamian–Persian Gulf region, despite uncertainties in the properties of unpenetrated source rock.