Reactivity of metastable water in hydrothermal heavy crude oil and carbonaceous compounds conversions

Abstract

© 2020. The geological reserves of ultra viscous hydrocarbons are enormous and commensurate with the world reserves of conditioned oils. The technologies currently known provide the extraction of only 10 %-15 % of the ultra-viscous hydrocarbons. The main methods of extraction are based on hydrothermal exposure aimed at reducing the viscosity of the fluid due to the injection of superheated steam into its reservoir. The work described is aimed at the study of the composition and the properties of Ashalchinskoye oil converted by hydrothermal transformation referring to the region of an anomalous change of the properties of water near its critical point in presence of carbonaceous substances. It is shown that: (i) the subcritical water has a high reactivity with respect to the molecules of tar and asphaltenes present in the super-viscous oil; (ii) the dehydrogenation and the hydrogenation reactions occur to a significant degree, and (iii) the coke formation reactions are inhibited. The thermolysis of the super-viscous oil in supercritical water in presence of carbonaceous matter goes in the direction of formation of paraffin-naphthenic compounds on the ground of significant destruction of the aromatic hydrocarbons present. The prevailing reactions and the degree of hydrocarbons conversion of super-viscous oil in sub-and supercritical water in presence of anthracene substances, iron oxides and nickel are identified.