Geochemical evaluation of oils in the Sarvak and Darian reservoirs in Resalat and Reshadat oil fields in the Persian Gulf

In order to determine the physico-chemical characteristics of oils from upper Sarvak and Dariyan formations, 4 oil samples collected from Reshadat and Resalat oilfields were analyzed. Physical properties of oils (e.g. the API gravity), indicates that Dariyan oil in both Resalat and Reshadat oilfield is similar to (with low pour points and high sulfur contents) the oils from Sarvak reservoir. Based on geochemical results, Dariyan and Sarvak oils exhibits paraffinic oil characteristics; and probably originated from a common source rock. No oil alteration like biodegradation and leaching has been recognized in these reservoirs. According to the concentration of Ni and V and Ni/V ratios, in studied oils, it seems the migration of hydrocarbon to these reservoirs taken place from Jurassic strata (Upper Surmaeh Formation).