Link for citation: Cheshkova T.V., Kovalenko E.Yu., Sagachenko T.A., Min  R.S. Chemical composition of petroleum from Krapivinskoe oilfield (message 5). Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2022, vol. 333, no. 3, рр.7-14. In Rus.

The relevance. Accumulation of data on the structure of asphaltenes of methane-naphthenic oil of the Krapivinskoe oil field from the Upper Jurassic deposits in the territory of the Tomsk region is one of the conditions necessary for solving problems associated with its production, transportation, and processing. The purpose of the work is to study the composition of asphaltenes in oil from the Krapivinskoe oil field using the oxidation reaction catalyzed by ruthenium ions. The object of investigation is the fraction of high molecular weight asphaltenes that make up the bulk of asphaltene components of the Krapivinskoe oil (87,9 % rel.). Methods: selective chemical destruction of C_ar.–C bonds using the oxidation reaction catalyzed by ruthenium ions and gas chromatography-mass spectrometry. Results. It was found out that the composition of high-molecular-weight asphaltenes of methane-naphthene oil contains fragments bound to the cores of their molecules through the С_ar.–C bridges and occluded compounds. Covalently bound fragments are represented by C₅–C₁₈ n-alkanes, aromatic structures of the biphenyl type, and naphthalenes located at the periphery of asphaltene molecules. Among the occluded compounds n-alkanes, alkylcycloalkanes, steranes, terpanes, alkylbenzenes, naphthalenes, phenanthrenes, fluorenes, pyrene, chrysene, fluoranthene, biphenyls, phenylnaphthalenes, dibenzothiophenes, benzonaphthothiophenes, indole, carbazol, quinoline, benzoquinolines, phenols, dibenzofurans, and benznaphtofurans were identified. Saturated hydrocarbons are typical biological markers; they are trapped in hollow cells of macromolecular formations of asphaltenes during kerogen cracking. Aromatic hydrocarbons and heteroorganic compounds are products of thermal destruction of parent asphaltenes; they are blocked by geomacromolecules at later stages of the formation of their macrostructure. The information obtained expands the understanding of the structure of asphaltenes in oil dispersed systems, so it may be used to construct a hypothetical model of their molecules.