Authors: Sergey F. KHAFIZOV graduated from Gubkin Russian State University of Oil and Gas in 1987. He is Doctor of Geological and Mineralogical Sciences, professor, member of the Russian Academy of Natural Sciences and AAPG, head of the Geology of Hydrocar- bon Systems Department at Gubkin Russian State University of Oil and Gas (National Research University). He is specialist in the field of oil and gas fields exploration. He is author of 4 monographs and more than 60 scientific publications in Russian and international perio- dicals. E-mail: khafizov@gubkin.ru
Rebaz Abdalaziz HAMA AMIN graduated from University of Sulaimani in 2012 and Gubkin Russian State University of Oil and Gas (National Research University) in 2016. He is post-graduate student at the Department of Geology of Hydrocarbon Systems at Gubkin Russian State University of Oil and Gas (National Research University). His scientific interests are related with geochemical studies of oils and source rock samples and basin modeling. He is author of 2 scientific publications. E-mail: Rebaz_1989sa@yahoo.com
Natalia N. KOSENKOVA graduated from Lomonosov Moscow State University in 1980. She is Candidate of Geological and Mineralogical Sciences, associate professor of the Department of Geology of Hydrocarbon Systems at Gubkin Russian State University of Oil and Gas (National Research University). She is specialist in the field of oil and gas fields exploration. She is author of 4 monographs and more than 20 scientific publications in Russian and international periodicals. E-mail: N.N.Kosenkova@gubkin.ru
Marina I. TRUNOVA graduated from Gubkin Russian State University of Oil and Gas in 1982. She is Candidate of Geological and Mineralogical Sciences, associate professor of the Department of Geology of Hydrocarbon Systems of Gubkin Russian State University of Oil and Gas (National Research University). She is specialist in the field of oil and gas fields exploration. She is author of more than 20 scientific publications. E-mail: mtrunova@gmail.com
Abstract: Gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS) methods are used to analyze crude oils obtained from Mil Qasim (MQ-1) and Sarqala (S-1) oilfields of south-eastern part of Iraqi Kurdistan using different biomarkers coefficients. Biomarkers characterization are used to provide information on the source of the organic matter, depositional environment, degree of maturity, age determination of the crude oils and their correlation between each other. The used data include normal alkanes and acyclic isoprenoids distributions, terpans, hopanes, steranes and diasternes aliphatic biomarkers, the distribution of aromatic biomarkers naphthalenes, dibenzothiophene, phenanthrene, methyldibenzothiophenes and stable carbon isotope. The oil samples from Mil Qasim and Sarqala oilfields are characterized by a low Pr/Ph ratio (< 1,0), a relatively low oleanane ratio, abundance of moderate C27 regular steranes and diasteranes, a relatively high C30 sterane index, the presence of tricyclic terpenes, relatively high dibenzothiophene / phenanthrene ratios, high CPI ratio (≥ 1,0) and high Ph/nC18 ratio. All of the above parameters indicate that the source rocks represented by calcareous marls were deposited under anoxic — reducing marine environments with type II of organic matter and were generated at moderate stage of maturity. All of the age diagnosed biomarker parameters indicate that the source of oils in Mil Qasim and Sarqala oilfield are the Lower Cretaceous formations (Balambo-Qamchuqa formations). Two samples of oil from the Mil Qasim field (MQ-1) and oil samples from the Sarkal field (S-1) show an excellent oil-oil correlation based on the comparison of biomarker characteristics.<
Index UDK: 550.4+553.98(55)
Keywords: biomarker, correlation, Iraqi Kurdistan, organic matter, oil, depositio- nal environment, maturity of the oil
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