Upgrading of ultra-viscous oil using iron based catalyst under microwave radiation

Metal-containing catalyst particles formed within the reservoir exhibit the capability to absorb microwave (MW) radiation, thereby enhancing the efficiency of MW field impact on the conversion intensity of heavy oils. The exposure of the Ashalcha oil samples to the microwave field was conducted for varying durations, ranging from 5 to 30 min. A catalyst precursor, iron tallate, was synthesized and loaded with 0.2 % metal and 2 % oil. The products of catalytic MW-radiation were analyzed by viscosimetry, SARA, GC-MS, molecular mass determination, FTIR-spectroscopy. Through experiments conducted with varying exposure durations, it was observed that a 30-minute MW radiation led to a noteworthy 50 % reduction in oil viscosity compared to its initial state. A decrease in the molecular weight of Ashalcha field oil by approximately 35 % was identified when using the catalyst precursor at the magnetic field maximum, compared to the original oil. Moreover, the addition of the catalyst facilitated a more uniform and rapid heating of oil samples during microwave thermolysis. As a result, this combined approach triggered the emergence of n-C10, C11, and C12 hydrocarbons within the saturated fraction, alongside alkylbenzenes C10–C13 and alkyltetralins C11–C13 within the aromatic fraction. It was also shown that, following microwave exposure of oil-saturated rock from the Ashalcha field in the presence of the catalyst, the specific surface area increased from 96.26 mm²/mm³ to 100.62 mm²/mm³ after treatment.