Aquathermolysis of heavy oil in the presence of bimetallic catalyst that form in-situ from the mixture of oil-soluble iron and cobalt precursors

Abstract

The design of highly efficient catalysts of cracking reactions for intensification of thermal enhanced oil recovery technologies is a relevant task. Moreover, the cost-effective industrial synthesis of such catalysts is very important. In this paper, we discuss the efficiency of bimetallic catalyst, which forms in-situ from the mixture of oil-soluble iron and cobalt precursors, on the processes of upgrading heavy oil in the reservoir of Tatarstan Republic (Russia). A simulation of aquathermolysis was carried out in a high-pressure reactor – autoclave at 150-250оС. The treatment time varied from 6 to 24 hours and the share of catalyst and hydrogen donor was 2 %wt. each. The phase composition of the active form of binary catalyst was estimated from the result of X-ray diffraction measurement. It is characterized by the presence of individual (Fe3O4 and Fe2O3) and mixed oxides with ideal stoichiometry – СоFe2O4. The formation of cobalt sulfide (CoS2) was observed, which indicates the destruction of C-S bonds in high-molecular components of oil. According to the results of SARA-analysis and rheology behavior, the catalyst intensifies destructive processes of resinous compounds (their content reduces more than 45%). This provides an increase in the content of saturated hydrocarbons by 16% and redistribution of aromatic fragments in hydrocarbons with hybrid structure. Thus, the reduction of dynamic viscosity by 32% was succeeded.