CFD Modeling of Heat Transfer in Oil Filling and Offloading of SDPSO Storage Tank

Abstract

A deepwater Spar Drilling Production Storage Offloading (SDPSO) floating system that consists of a classic Spar hull with dry–tree production, oil storage and offloading has been proposed for offshore oil exploitation. One of the key features of the SDPSO is the oil storage system, which includes the mid–section of the classic spar hull for oil storage providing a large storage capacity of more than 500,000 barrels of oil. In the working condition, oil storage tank is fully filled with oil and seawater, the storage and offloading of oil are achieved by seawater displacement and oil–water separation. However, a seawater displacement oil storage system does raise the problems of stability of the oil–water interface, possible sludge contamination of the water and corrosion of the internal surface of the storage tank during oil filling and offloading operations. It is clear that sludge deposit and corrosion effect are closely related to the temperature distribution of crude oil and seawater inside the tank. Therefore, it is necessary to investigate hot–oil/cold–water heat transfer in the SDPSO oil storage tank during both operations and storm conditions. For this purpose, CFD modeling and numerical studies were performed for a simplified oil storage system of the SDPSO platform in an effort to gain better understanding of the heat transfer problem.