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ON THE NATURE OF HYDROCARBONS IN SERPENTINITES

S. V. Shadrina 1, A. A. Redina 2, E. A. Romanov 1

1 OOO Koretest servis, Tyumen, Russia; 2 V.S.Sobolev Institute of Geology and Mineralogy SB RAS, Novosibirsk, Russia

The article presents the unique results of the study and photographs of the core of serpentinites saturated with hydrocarbons (HC). During the core study, the rock mineral composition was investigated, the order of mineral formation as well as the nature of serpentinite saturation with hydrocarbons was determined,pyrolytic analysis of samples was carried out, and the geothermal history of rocks was assessed. The model of reservoir formation in serpentinites and metasomatites based on them, time and stage of its filling with HC was proposed. It was identified that the serpentinite massif at a certain stage of alteration is represented by a porous reservoir, transforming into a porous fractured one under the influence of tectonics. The features of structural and tectonic structure of the massif, its slaty structure, determine the alternation of sites with various reservoir types in the section. Due to the different pore sizes caused by the different mineralogicalrock composition, a natural separation of incoming HC was taken place/is taken place, as a result of of the process, an “interlayering” of intervals with different saturation – oil-saturated, gas-saturated and without saturation in the section is noted. The input of HC into the rock was pulse-coupled and is probably currently coming from deeper rocks.

Keywords: serpentinites, mineral composition, reservoir, pyrolytic studies, hydrocarbons.

DOI 10.20403/2078-0575-2023-4a-63-76

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