Concentrating Solar Power Applied to EOR: High Temperature Fluid Circulation for Enhancing the Recovery of Heavy Oil Available to Purchase

Over the last decade there were new focuses for the use of renewable energies to enhance the recovery of fossil fuels in a cleaner and effective manner. In this paper a technical-economical feasibility study on the integration of Concentrating Solar Power (CSP) technology into the enhanced recovery of heavy oil from complex field by thermal method is reported. A hot fluid directly heated by solar energy is continuously circulated into a closed circuit through the reservoir to increase and sustain the reservoir temperature. The aim is to increase the potential production of unconventional reserves by lowering the oil viscosity. In the analyzed configuration, the closed loop is positioned in a heating well separated by the production well. Size and geometry of the circuit were optimized. A case study was chosen and the preliminary dimension and efficiency of the solar plant as well as the expected increases on oil production were estimated for different scenarios (different hot fluid temperatures, different percentages of the total thermal energy supplied by the solar resource). The results showed that it is possible to greatly enhance the recovery of heavy oil by this thermal method. Besides the estimated recovery is higher than those achievable by electrical heating as it is possible to reach very high temperatures (390°C) of the circulating oil. This thermal method represents also an efficient exploitation of the solar energy for EOR applications. From the economic point of view, the results are encouraging also if the comparison with a fossil solution is very sensitive to the location of the plant (different direct solar irradiance) and the gas price. As solar plant requires large land, for off-shore applications the described thermal method is suitable only if a fossil fuel is employed to heat the oil.