Experimental Investigation on the Comprehensive Performance of Radio Frequency Heating Technology for Heavy Oil Recovery

Several numerical simulations of RF heating have been carried out previously on the estimation of heavy oil recovery capabilities. Experimental efforts, however, are needed to comprehensively evaluate the performance of RF heating technology. In this study, an RF heating experimental system with the maximum output power of 20 kW is designed. In this system four special custom-made experimental pipes provide the space where the interaction between EM waves and oil sands occurs. Temperature data are recorded continuously by fiber optic temperature sensors. Initially, the temperature profiles of oil sands and quartz sands at 10 kW are obtained. Afterward, the step changes in temperature of pipes bottoms are captured to investigate the drop process of heavy oil. The influences of different powers and distances from the antenna on temperature and recovery ratio are analyzed. Finally, according the measured data, the calculation for the energy to oil ratios under various combinations of time and power is done to evaluate the energy consumption of RF heating technology. Experimental results indicate that the power increase contributes to improve the oil sands temperature, shorten the time required for heavy oil to flow and cause high average recovery ratio. The capability of oil sand to absorb EM waves is stronger than that of quartz sands. Additionally, the effects of distance from antenna on average recovery ratio are in good agreement with the change rules of temperature. There exists an optimal combination of heating power and time that makes the lowest value of energy to oil ratio.