Evaluation of the hydrocarbon-generating potential of the Shiranish formation of the Euphrates fault trough using the Rock-Eval method

UDK: 553.98.061.82:550.84

DOI: 10.24887/0028-2448-2025-6-29-33

Key words: source rocks, Euphrates fault trough, Shiranish formation, Rock-Eval method, oil and gas potential

Authors: . Jomaa (Gubkin University, RF, Moscow); A.S. Kurushina (Gubkin University, RF, Moscow); S.F. Khafizov (Gubkin University, RF, Moscow); K.I. Dantsova (Gubkin University, RF, Moscow)

The article presents the results of studying the rocks of the Shiranish formation using the Rock-Eval method. The hydrocarbon-generating potential of rocks and the origin of organic matter were assessed; the patterns of organic matter maturation were identified. Based on the obtained geochemical parameters, the Shiranish formation was divided into two subformations: the lower Shiranish formation (LSF) and the upper Shiranish formation (USF). USF in turn was subdivided into two submembers: USF-1 and USF-2. The analysis of rocks indicates the presence of oil source intervals in the lower part of the USF-1. The USF is characterized by a kerogen type from II to II-III, as well as constantly increasing contents of total organic carbon (TOC) and the hydrogen index (HI). In contrast, LSF is characterized by a kerogen type II-III and lower TOC and HI values. The oxygen index (OI) values in the rocks of the LSF are significantly higher than in the USF. All studied rock samples of the Shiranish formation, collected from seven wells located in the Euphrates fault trough, are oil source rocks. The degree of maturity varies from immature OM in the eastern and northeastern fault troughs to mature OM towards the central fault trough, which is located in the main oil generating zone.

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