Improvement of the quality of heavy crude oil and reducing the concentration of asphaltene hydrocarbons using microwave radiation during acidizing.

Acidizing boosts healthy production, while microwave radiation techniques and hybrid methods are emerging to enhance hydrocarbon extraction and oil production efficiency. This research systematically investigated the interaction between microwave radiation and working acid on crude oil. Crude oil samples were positioned adjacent to an acid solution and subsequently subjected to microwave radiation at power levels of 1300 W (100% Microwave) and 780 W (60% Microwave) for durations of 1, 2, and 3 min. A comprehensive suite of analyses was performed, including viscometric assessments, interfacial tension measurements, density measurements, asphaltene quantification via extraction tests, sludge analysis, nuclear magnetic resonance (NMR) spectroscopy, pH measurements, and Fourier transform infrared spectroscopy (FTIR). The results indicate that the polarity of both the crude oil and the acid solution enhances the absorption of microwave radiation. FTIR analysis revealed an increase in polar functional groups relative to non-polar groups, suggesting significant molecular interactions; the NMR test also proves this trend. Furthermore, viscometric and surface tension tests demonstrated that increased polarity correlates with enhanced microwave absorption. The combined method, which is characterized by the simultaneous presence of polar acid solution and an electromagnetic field, led to alternating fluctuations (increase and decrease) of surface tension, viscosity, density, pH, and sludge during the tested process. It also caused a decrease in the concentration of asphaltene hydrocarbons; the reason for these intermittent changes is the simultaneous effects of changes in the strength of acid solutions and increasing or decreasing the power of microwave radiation at a particular time.