source rock

In this research, the hydrocarbon generation potential of probable source rocks was evaluated. Results of the Rock-Eval pyrolysis showed that, among the studied samples, the Pabdeh and Kazhdumi formations contained marine type-II/III kerogen and showed good to very good oil generation potential, making their organic matter (OM) immature and immature-in early oil production window, respectively. Containing mixed type-II/III kerogen, the Gadvan Formation was found to be within the oil production window, in terms of maturity, showing good hydrocarbon generation potential. The Sargelu and Garau formations were found to be dominated by type-II kerogen, exhibiting very good hydrocarbon generation potential. It was further figured out that the Garau and Sargelu formations were in the middle and late oil production window to early wet gas window, respectively. Outcomes of geochemical analyses on the studied crude samples showed that all of them were originated from the same source, with the potential source rock exhibiting a marl-carbonate lithology deposited in a reducing environment. The OM content of the probable source rock was primarily made from type-II kerogen formed in a marine environment, with evidence of intrusions by OMs dominated by terrestrial kerogen has been further observed. The studied crude samples were found to be sourced from Lower Cretaceous to Middle Jurassic source rocks with maturity levels corresponding to middle to late oil production window so that the crude samples from the Fahliyan Formation exhibited the highest levels of maturity. Sargelu and Garau formations were proposed as potential source rocks for the crudes accumulated in the Abadan Plain.

Summary The Middle Jurassic Sargelu Formation consists of gray shales and argillaceous limestones in the southwestern Iran. According to lithology, petrophysical and geochemical characteristics, Sargelu is considered as a probable active source rock in the southwestern Iran. The purpose of this paper is to evaluation of hydrocarbon generation potential of Sargelu Formation and its distribution of quantity, quality and maturity in Lorestan, Abadan plain, Dezful embayment, and northwestern Persian Gulf. The evaluation is based on Rock-Eval and vitrinite reflection results of 365 samples from 16 fields and outcrops. Geochemical parameters indicate very good hydrocarbon generation potential for Sargelu during the geological time in different parts of study area. IntroductionSeveral petroleum systems are active in the southwestern Iran and different formations are considered as first or secondary source rock for them. Sargelu Formation is one of the richest source rocks for Jurassic petroleum system in the southwestern Iran and Arabian adjusting areas. Although several researches have been evaluated petroleum potential of Sargelu in the south-west of Iran, none of them study Sargelu in a regional scale. This work assesses hydrocarbon generation of Sargelu (quantity, quality and maturity) in the regional scale in the southwestern Iran and northwestern Persian Gulf. The study area is approximately 725 km long and 350 km wide. Methodology and ApproachesThis study discusses the petroleum potential of Sargelu Formation in south west of Iran, based on data collected from different studies carried out previously. 365 Rock-Eval and 31 vitrinite reflectance data from 16 fields and outcrops were uploaded and evaluated by p.IGI.3.5.1 software. Results and ConclusionApproximately 95% of the samples have a TOC content > 1%, which is consistent with good to very good source rock potential. TOC and HI vary from 0.13 to 26.42 and from 0.9 to 1168, respectively. Samples from eastern Lorestan basin (Gashoon, region 1 to 5) indicate good to very good petroleum potential with kerogen type II, while samples from Dezful embayment and Abadan plain indicate fair to good petroleum potential with kerogen type III and II/III. Moreover, samples selected from western Lorestan basin have kerogen type III/IV. The trend of maturity of Sargelu source rock in the study area is exactly in inverse relation to TOC and HI distribution indicating Sargelu in western Lorestan basin, Dezful embayment and Abadan plain generates high amount of oil and gas during geological time with increasing its maturity.

This paper aims to investigate the hydrocarbon potential and organic matter maturity of Sarchahan and Faraghun formations between  coal layers. To do this, we implemented the kinetic parameter and Rock-Eval 6 Pyrolysis analysis methods. Results showed that moving toward the coastal Fars (Sarchahan Formation) and from south of Iran to the central part of Fars bay (Faraghun Formation), there is an increase in the maturity of the organic matter.

This paper summarizes geochemical analysis and burial and thermal history modeling of Dorood and Nowrooz oil fields located in northwestern Persian Gulf. 5 samples of Fahliyan (Yammama), Asmari and Fahlian (Manifa) reservoirs in Dorood - Kharg oil field and Kazhdumi (Nahreomr) and Kazhdumi (Burghan) reservoirs in Nowrooz oil field were analyzed geochemically. Samples are mainly paraffinic oil type. Oil in Dorood - Kharg reservoirs were originated from carbonate sulfur rich source rock but marl or calcareous shale rock is responsible for oil generation in the Nowrooz field. Isotopic studies indicate that Kazhdumi (Nahreomr) reservoir is likely contain composite oil. Based on the results of burial and thermal history modeling of Dorood and Nowrooz oil fields, the Surmeh (Arab - D) formation began to generate oil from about 125 million years ago and lies in main oil window and Kazhdumi (Dair) formation is thermally immature in Nowrooz oil field. Kazhdumi and Gadvan formations lie in early oil zone and Pabdeh formation is immature in Dorood oil field.