Study on the Efficiency of Radio-Frequency Electromagnetic Field for Heat Treatment of Heavy Oil and Bitumen

Abstract

In recent years, the use of high-frequency electromagnetic fields has become a widely used technology for heating of complex hydrocarbon systems such as heavy oil and bitumen. The urgency of this technology is connected with the fact that for these systems, it is important not only to reduce the viscosity by heating, but to a greater extent to destroy stable structures of high-molecular hydrocarbon compounds, which is achieved by the effect of electromagnetic radiation. The most effective method of giving not only heat but also a “destructive” effect in such media is a heating by radio-frequency electromagnetic field. The advantage of this heating method as compared with the other types of treatment is that it involves large volume of liquid and the speed of the process is very high. In the present work the results of experimental study and numerical modeling of heat and mass transfer in high viscosity hydrocarbon liquid, which viscosity and thermal conductivity are temperature dependent, under induction heating and heating by radio-frequency electromagnetic field considering the thermal convection are presented. The thermal motion of the heavy hydrocarbon liquid with temperature-dependent viscosity and thermal conductivity in the space between two coaxial cylindrical tubes with various methods of heating has been studied. The comparative efficiency of the radio-frequency electromagnetic field heating in comparison to the induction heating of a heavy hydrocarbon liquid system was shown by mathematical modeling. It was proved that in both cases the single vortical flow structure is formed in the whole volume of the liquid, which expands as the liquid reaches fluidity temperature. However, radio-frequency electromagnetic heating provides a more homogeneous redistribution of heat and prevents local overheating of the liquid, which is observed in the process of induction heating. Besides, in the case of induction heating, a three times weaker in power consumption source is required for adequate heating; this fact indicates that radio-frequency electromagnetic heating is significantly more efficient when dealing with high-viscosity hydrocarbon liquids in comparison to the induction heating.

AAPG Datapages/Search and Discovery Article #90259 ©2016 AAPG Annual Convention and Exhibition, Calgary, Alberta, Canada, June 19-22, 2016