Siberian Federal University

The transformations of resin-asphaltene components of heavy crude cracking products under conditions simulating in- situ hydrothermal upgrading were studied. It was found that the depth of resin and asphaltene transformation increases with increasing process duration and temperature. The presence of water slows down reactions that lead to the formation of gaseous by-products (a reduction of up to 44 % rel.) and, as a result, to the accumulation of oils. Optimum process conditions are achieved at a temperature of 300 °C, a duration of 24 hours, and a water: oil ratio of 3:7. It is shown that, with the specified aquathermolysis parameters, the total content of high-molecular components (resins and asphaltenes) decreases by almost 32 % rel. The patterns of change in the calculated structural- group characteristics of average resin and asphaltene molecules indicate the intensification of condensation reactions. In particular, their acceleration is indicated by the enlargement of individual structural blocks of resin and asphaltene molecules up to 12 hours, including an increase in the number of aromatic rings, as well as the number of sulfur atoms and carbon atoms in aliphatic fragments. Subsequently, the largest resin and asphaltene molecules are sequentially transformed into densification products, the yield of which does not exceed 0.38 % by weight after 24 hours of aquathermolysis. After this, the molecular weight of the “newly formed” resin-asphaltene components, the number of aromatic and naphthenic rings, and the number of heteroatoms in their structure decrease