Improving the Performance of Heavy Oil Oxidation Using Oil- Soluble Copper-Based Catalysts in In Situ Combustion for the In Situ Upgrading Process

Copper tallate (Cu-Tall oil) was fabricated as a soluble catalyst in crude oil for the oxidation process of oil in in situ combustion. Catalytic efficiency of the synthesized catalyst was examined in the liquid phase by coupling thermogravimetry (TG) and Fourier transform infrared spectroscopy and in porous medium using a porous medium thermo-effect cell. Moreover, the catalyst effect on the oxidation reaction of heavy oil for in situ upgrading was studied using visual combustion tubes. The calculation of kinetics was done by different iso-conversional methods, excluding Ozawa-Flynn-Wall (OFW), Freidman, and Kissinger-Akahira-Sunose (KAS) models by TG analysis data. Results showed that activation energy for heavy crude oil oxidation on average decreased to 161, 166, and 152 kJ/mol from 191, 195, and 185 kJ/mol using OFW, KAS, and Friedman, respectively. Using Cu-Tall oil catalysts, the viscosity of the obtained oil reduced to 85 mPa center dot s from 2072 mPa center dot s during the oxidation process. A saturate, aromatic, resin, and asphaltene (SARA) analysis also revealed that the heavy oil oxidation process with a catalyst resulted in a reduction of high-molecular-weight compounds such as resins and asphaltenes to 7.18 and 1.56% from 20.98 and 5.91%, respectively, while light fractions including saturates increased from 28.79 to 43.05%. In high-temperature oxidation reactions, oil-soluble Cu-Tall oil decomposed to copper oxide nanoparticles (CuO NPs) as the active catalyst, which showed a significant temperature decrease during high-temperature oxidation. This kind of precursor has high catalytic activity and low cost that make it an acceptable catalyst to develop the oxidation of heavy oil during high rate production from heavy crude oil reservoirs.