Onsite recovery of heavy-oil is primarily done by thermal methods. The aim of these methods is to reduce viscosity of heavy oil to deploy it towards injection well. Unfortunately, these methods maybe inadequate for certain economic criteria and subject to environmental limitations. Additionally, they may not be compatible with certain types of reservoirs, examples: shales, deep reservoirs, etc. Recently, interest was devoted to electromagnetic heating with radiofrequency (RF) to overcome some of these problems. A theoretical model has been provided for Heavy Oil Recovery through RF waves which compete with the existing methods of EOR by thermal heating. A set of governing equations has been provided with an experimental model that proves the method more efficient than others. As a result, the interaction of an oscillating polar molecule with its neighbours takes place and it generates frictional heat, which raises the temperature of the medium.
In general, the EM heating process relies on preferential absorption of EM energy as the means of increasing temperature of dielectric materials. The ability of an EM wave to conduct energy to a medium is determined by the molecular composition of the medium. If the medium holds mobile molecules with molecular dipole moments, then torque is exerted on the polar molecules by the passing Electromagnetic waves and the alignment of dipole moments with the oscillating electric fields of the electromagnetic waves take place. As a result, the temperature of the medium is raised due to heat generated by friction as continuous encounters between oscillating polar molecules happen. Microwaves are very much effective to produce heat by getting sufficiently absorbed by the materials. Since crude oil is not a good absorber of microwaves, microwave receptors like activated carbon, nano-metal oxides, and polar solvents should be used to make the microwave process faster. Hence, further research is needed to implement the enhanced metal-nanoparticle incorporating electromagnetic heating (EMNIEH) at the field scale. In this case, the main question is how to inject nanoparticles into reservoir through the wellbore hole during EM heating.
Electromagnetic Heating is very much a substitute to aqueous thermal EOR methods for heavy oil recovery from shale reservoirs or high clay content or deep reservoirs. This technology can also be implemented in complex geological system as it is relatively less expensive and better for the environment. A theoretical model allows us to take stock of how we can optimize and increase the use of EM waves and RF to efficiently deploy it onsite.