Catalytic Activity of Nickel and Iron Sulfides in the Degradation of Resins and Asphaltenes of High-Viscosity Oil in the Presence of Carbonate Rock Under Hydrothermal Conditions

A study was made of the laws of transformation of the composition of high-viscosity oil under hydrothermal conditions in a porous medium of carbonate rock in the presence of transition metal sulfides formed in situ from an organically soluble precursor. It was determined that the catalysts provide a significant degree of degradation of asphaltenes. When using a catalyst containing nickel and iron in equal proportions, the viscosity becomes an order of magnitude lower than that of the initial oil and reaches a minimum value of 1360 mPa s. Owing to the presence of two different metals in the mixed catalyst makes, a wider range of carbon–heteroatom bonds in resins and asphaltenes of high-viscosity oil can be involved in in the conversion processes. Reducing the viscosity of oil under reservoir conditions makes it possible to increase oil recovery and decrease the carbon footprint of the produced oil due to an increase in the H : C atomic ratio.