DBPapers
DOI: 10.5593/sgem2017H/15/S06.024

FEATURES OF THE CHANGE IN THE COMPOSITION OF SOLID ASPHALTITE IN THE HYDROTHERMAL-CATALYTIC CONDITIONS

G. P. Kayukova, A. A. Al-Muntaser, I. Abdrafikova, A. V. Vakhin, V. P. Antipenko
Thursday 23 November 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgemviennagreen.org, SGEM2017 Vienna GREEN Conference Proceedings, ISBN 978-619-7408-26-3 / ISSN 1314-2704, 27 - 29 November, 2017, Vol. 17, Issue 15, 187-194 pp; DOI: 10.5593/sgem2017H/15/S06.024

ABSTRACT

The paper reveals the distinctive features of the change in the composition of natural bitumen - asphaltite from from the sandstones of the Permian sediments of the Spiridonovsky field in the territory of Tatarstan, in model experiments at a temperature of 250 °C, characteristic for steam-thermal impact on the formation, and the pressure in the system of not more than 2 MPa. The choice of low pressure is due to the fact that bituminous rocks in the Permian sediments occur at relatively shallow depths in the near-surface deposits of the sedimentary strata, which necessitates the development of special technologies for their extraction. The experiments used natural iron oxide - hematite. As a part of the products of asphaltite conversion under the influence of hydrothermal-catalytic factors, the content of hydrocarbons almost 4-fold, the content of alcohol-benzene resins and asphaltenes decreases. The content of benzene resins increases somewhat. The composition of asphaltite proved to be less stable than of heavy oils from age-old sediments, apparently due to special conditions for the formation of its composition in natural conditions under the influence of secondary low-temperature biochemical processes that led to the accumulation of thermally unstable resinous-asphaltene components. Compared with the original asphaltite, in the products of the experiment, the content of alkanes of composition C10-C30 substantially increases with an obvious predominance of homologues with an even number of carbon atoms in the molecule. The product is characterized by a lesser degree of aromaticity and content of sulfoxide groups. Asphaltenes increase the concentration of free radicals (R*), compared with the content of vanadyl ions (VO2+), and the morphology of their surface significantly changes. The increase in the structure-group composition of products of oxygen-containing groups corresponding to alcohols and ethers confirms the course of oxidative cracking processes under the given conditions. The results of the studies showed the possibility of upgrading the composition of solid bitumen - asphaltite in in situ conversion by diluting its composition with lighter newly formed hydrocarbons, due to the destruction of its high molecular weight components.

Keywords: asphaltite, composition, properties, genesis, hydrothermal processes, hematite.