A Simulation Study on the High-Frequency Electromagnetic Heating Heavy Oil Reservoir and Analysis of Influencing Factors

Abstract

In the situation of continuous low oil price worldwide, the conventional thermal recovery technologies have gradually exposed the defect of low profit. Therefore, there have been increasing research interests focused on the electromagnetic (EM) heating method for enhanced heavy oil recovery. This paper proposes an application of waveguide to transmit high-frequency EM waves from the surface into the underground for heating the target area; besides, the factors affecting the EM heating effect are analyzed. Originally, a three-dimensional simplified model composed of reservoir, rectangular waveguide and resonant cavity is established. Then, the governing equations of EM field and temperature field are coupled to quantitatively describe the heating process, and at length, the effects of the operating parameters of EM heating and of the reservoir properties on temperature distribution are investigated. Simulation results are validated by the actual data obtained from laboratory experiment. For the constant reservoir properties, the increase in EM power can significantly raise the reservoir temperature and expand heating area. Although the higher EM frequency sharply heightens the reservoir temperature, the heat only penetrates limited distance. Reservoir temperature ascends as the rise of the conductivity, porosity and water saturation of the reservoir. In addition, the relative permittivity of water is a vital physical parameter during the EM heating process. Those results can provide guidance for the field-scale implementation of EM heating technology.