Enhanced Oil Recovery by In-Reservoir Hydrogenation of Carbon Dioxide Using Na-Fe 3 O 4.

In-situ conversion of carbon dioxide into value-added products is an essential process in terms of heavy oil upgrading and utilization of the main anthropogenic greenhouse gas. In this paper, we discuss a synthesis of sodium-coated magnetite (Fe₃O₄) particles for in-reservoir hydrogenation of CO₂. The performance of the obtained catalyst was tested in upgrading of heavy oil in a High Pressure/High Temperature (HPHT) reactor imitating the reservoir conditions during steam injection techniques. The experiments were conducted for 48 h in a CO₂ environment under the steam temperature and pressure of 250 °C and 90 bar, respectively. The results showed irreversible viscosity reduction of oil from 3931 mPa^.s to 2432 mPa^.s after the degassing of unreacted carbon dioxide. The content of resins in the composition of upgraded oil was significantly altered from 32.1 wt% to 19.01 wt%, while the content of aromatics rose from 32.5 wt% to 48.85 wt%. The GC-MS results show the presence of alkyl benzenes and phenanthrenes, which were initially concentrated in resins and asphaltenes, in the aromatics fraction of upgraded crude oil. Thus, Na-Fe₃O₄ exhibits promising results for in-situ heavy oil upgrading through the hydrogenation of carbon dioxide, which contributes not only to the reduction of greenhouse gas emissions, but also enhances heavy oil recovery. [ABSTRACT FROM AUTHOR]