Integration of Concentrating Solar Heat into Oil and Gas Operations for Increased Sustainability

According to Eni's mission to reach carbon neutrality in the countries where it operates, the development of renewable energy could be a key element in the company's strategy for evolving the business model towards a low carbon scenario. In this context, concentrating solar technology can provide a real solution in order to goal the carbon neutrality. Solar thermal energy could be an alternative source to the fossil fuel in industrial processes and also in the oil&gas sector, where the upstream operations (dewatering, stabilization, sweetening…) require substantial amounts of heat. Usually this heat is easily produced by combustion of natural gas available at the oil&gas site. Concentrating Solar Heat (CSH) technology allows to produce process heat by using specific collectors that concentrate the solar radiation onto a receiver where a heat transfer fluid is heated at medium/high temperature. A thermal energy storage can be added to the solar field to increase the solar fraction and reducing so the CO2 emissions. The fraction of thermal energy not covered by the CSH plant can be provided by a fossil source that acts as a back-up. With this in mind, a pre-feasibility study was carried out for the integration of a medium temperature(∼200-300°C) concentrating solar plant with or without a thermal storage system and a back-up gas heater in an oil&gas site located in North Africa. The solar heat partially replaces the duty necessary to the heat exchangers that heat the crude to guarantee the separation from water and best stabilization. Reflective areas of the solar field and total occupancy, thermal energy production during the year, solar multiple and preliminary evaluations of cost of investment are presented. Obviously, the reduction of CO2 emission increases with the solar fraction but the competitiveness and cost-effectiveness of the integration strongly depend on the local cost of natural gas, the presence of government incentives, CO2 credit tax, etc. In any case the proposed solution represents an important step towards energy transition.