Geochemical investigation of Kazhdumi and Pabdeh formations suggest a shaly and carbonate lithology as well as a suboxic-anoxic marine depositional environment for both formations. On the other hand, the thermal maturity of the Kazhdumi Formation is equivalent to the mid of oil window while thermal maturity-related parameters show that the Pabdeh Formation has not entered the oil window. Biomarkers are indicative of derivation of the four oil samples from a carbonate-shaly or marly Source rock. Also, thermal maturity-related biomarkers reflect a peak mature stage for all of the four samples. Different values of oleanane index in oil samples is implying a more significant role of the Pabdeh Formation in hydrocarbon embedded in 36, 56, 55 wells in compare to well number 22. In general, oil-Source correlation introduces both Kazhdumi and Pabdeh formations as Source rocks for the crude oils.

Source rock is one of main elements in petroelum system. In order to investigate a petroleum system in an oil region, it's necessary to recognize the characteristics of Source rocks. In this study the Source rocks of the Darkhovain oil field in Abadan plan are investigated. In this way, gamma rays and sonic log are used and Source rock zones separated in Pabdeh, Garu, Gotnia, Najmeh, Sargelu and Nyriz formations. These zones sampled and total organic carbon of samples determined with rock Eval analysis. Acording to rock Eval results, Sargelu and Garu zones have good to excellent total organic carbon and good to moderate genetic potential. These zones have more thickness then the other zones. Kazdumi Source rock samples show range of good to very good in total organic carbon and a range of moderate to good in genetic potential. Pabdeh, Sarvak and Surgah samples are poor in organic matter and have low genetic potential. Acording to this study, Sargrlu and Garu zones are main Source rocks and Kazdumi and Nyriz zones are minor Source rocks in Darkhovain field.

The Khaviz oil field located in Dezful embayment is one of Iran’ s southwest oil fields. In this study, a total of 28 cutting samples from Kazhdumi formation (well No. KZ1, Khaviz oil field) were subject to geochemical investigation using rock-Eval pyrolysis for the first time. The results of pyrolysis indicated that Kazhdumi Source rock has significant hydrocarbon production potentiality and already entered the oil generation window. As inferred from the diagram of OI versus HI, Kazhdumi Source rock contains organic matter type II kerogen deposited in paralic environment with anoxic to suboxic conditions. Using the diagram of S2 versus TOC, the absorbed carbon content, neutral carbon, and active carbon were calculated to be 0. 42, 0. 39, and 2. 43 wt. % respectively.

Despite the fact that kerogen decomposition has not been yet very well understood, it is possible to obtain kinetic parameters which correlate with both empirical and natural geologic data by pyrolysing samples in closed and open systems. In this study, in order to determine hydrocarbon Source rocks kinetic parameters, synthetic maturation by using open pyrolysis system (rock-Eval) was used. In order to determine the equation of the real pyrolysis temperatures, the rock-Eval pyrolysis oven was calibrated against three standard samples. Three Source rock samples from three well known Iranian Source rock formations namely Pabdeh, Garu and Kazhdumi were anafyzed at temperature rates of 25, 15, 10 and 5°c/min and their kinetic parameters including activation energy distribution, Arrehnus coefficient and the amount of generated hydrocarbon were determined.

To evaluate the relationship between total organic carbon (TOC) and rock-Eval S2 (petroleum potential) of petroleum Source rocks, a total of 180 outcrop samples from the black organic matter–rich facies of Mesozoic strata from a locality of southwest of Iran were investigated using rock-Eval VI pyrolysis and Leco Carbon Analyzer. The linear regression is applied to determine the correlation between Leco TOC and rock-Eval S1 and S2. The accuracy of the proposed model by this method has approximately 95% conformity according to the rock-Eval S2 and Leco TOC data (TOC=0.492 + 0.174 S2). Then, by using the P value method, it was determined that TOC is a function of S2 and S1 only causes the fluctuations. By means of sensitivity analysis of TOC with respect to S1 and S2, it was shown that TOC has a linear relationship with S2 and does not have any noticeable correspondence to S1. The result of this study can be used to evaluate petroleum potential (S2) of organic matter–rich facies by using TOC obtained by Leco Carbon Analyzer. For the studied samples from the organic matter-rich facies, organic carbon richness is a quality and quantity index of petroleum potential.

In this study 44 Sedimentary rock samples from the Amadeus Basin, in southern portion of the Northern Territory, Australia, were analyzed by two well-proven organic geochemical methods: rock-Eval (RE) pyrolysis and gas chromatography–mass spectrometry (GC-MS) analysis. These techniques were used to obtain independent parameters on organic matter composition, its thermal maturity, and environment of deposition. This study reveals a close concordance between rock-Eval pyrolysis data and polycyclic biomarkers parameters such as steranes.RE pyrolysis in conjunction with GC-MS analysis show that the Amadeus Basin sediments contain a variable but notable organic-rich facies in the Horn Valley siltstone and prove an unequivocal evidence for Type-II organic matter, which lies dominantly to the peak stage of the conventional oil window (end of diagenesis-middle of catagenesis). The case study from the Amadeus Basin shows that these methods remain undoubtedly suitable for a good assessment of the petroleum potential of Source rocks and rapid geochemical characterization of sedimentary organic matter, and can be used in other similar basins.

Organic geochemical evaluation of the Madbi Formation as the main Source rock of the Al-Jawf Basin, NE Central Yemen was the main objective of this study. The organic geochemical methods used in the study include: rock-eval pyrolysis, total organic carbon, and optical measurements as the vitrinite reflectance and thermal alteration index. In this study, 67 well core and side-well core samples of the H-1 and K-1 exploratory wells of the Al-Jawf Basin were analyzed to calculate the several organic geochemical and optical parameters. The obtained results show the presence of strong Source rock probabilities within the Madbi Formation in this basin. The results are classified into three categories: poor, fair, and good Source rocks, with a mixed marine Kerogen type II/III and continental Kerogen type III. The maturation of Source rocks was affected by heating and re-cycling of heat events during the Cretaceous and Tertiary periods. This interpretation is strongly related to the breakup of the southern Gondwanaland and the opening of the Red Sea and Gulf of Aden. Based on the evaluation of the Source rocks, the shale, calcareous shale, and claystones of the Madbi Formation are considered the main Source rocks in this basin. According to the present study, the hydrocarbon potentiality is good to fair grade in the Al-Jawf Basin.

The Persian Gulf among the areas with the greatest potential for exploration and development of hydrocarbon reservoirs in the word. The Gadvan Formation (Barremian to Early Aptian) is one of the formations with good Source rock potential in this region. In this article, the hydrocarbon potential of the Gadvan Formation is investigated in the Iranian sector of the Persian Gulf. For this purpose, a total of 87 samples was taken from the Gadvan Formation in the 18 oil fields are analyzed by rock-Eval pyrolysis. The thickness of the Gadvan Formation ranges from 35 to 354 meters. The Formation reaches a thickness of 354 m in the southern part of the study area and also in the Strait of the Hormuz. The results of rock Eval pyrolysis indicate that the Gadvan Formation was deposited in a marine environment and its organic matter is mainly composed of kerogen III and II/III. The TOC ranges from 0.26 to 2.16 wt. % and the average TOC content of the Gadvan Formation is 0.97 wt. %. TOC content increases toward the west of the Persian Gulf. Tmax values range from 410 to 458°C, and in 86% of the samples the Tmax is less than 435oC.Moreover, a burial history and thermal maturity investigation were performed on the Gadvan Formation in 3 oil fields to assess its thermal maturity and evolution through time. The results confirm the rock Eval results and indicate that the Barremian to Early Aptian-aged Gadvan Formation is currently immature in the center part of the Persian Gulf and reached to the early range of maturity for oil generation in the margin.

With respect to distribution of Surmeh Formation in Persian Gulf region, this formation may act as candidate Source rock for hydrocarbon accumulation in this region. A comprehensive geochemical analysis including rock-eval Pyrolysis, Gas Chromatography (GC), Gas Chromatography–Mass Spectrometry (GC-MS), was carried out on cuttings, in order to determine its hydrocarbon potentiality. Based on rock-Eval data, the organic matter of the Surmeh formation is type II and III kerogen, with low maturity being at the end of diagensis stage. It exhibits a poor Source rock characterization with low content of TOC. A close similarity can be seen, between organic matter extracted from Surmeh sample with that of oil sample collected from Upper Dariyan, Lower Dariyan and Maudud reservoir in the field. Biomarker results indicate that an open marine and few terrestrial input Source rocks deposited in an anoxic condition with carbonate origin. Based on geochemical investigations Surmeh Formation isn’t suitable Source rock in the study area locally. Biomarker derived from rock extracts and trapped oils indicated that they share the same origin and were stained by laterally migrating oils from distant area.