Model validation and stability analysis for operation projects in Jintan Salt Cavern for strategic oil storage of China

Underground salt cavern oil storage reservoirs have been adopted in many countries because of their long service life, limited space requirements, and low investment cost. In contrast, the use of salt caverns for oil storage is rarely seen in China. Currently there is only one underground salt cavern strategic oil storage reservoir under planning and construction, in the city of Jintan, Jiangsu province. To help understand the thermodynamic behaviors of oil and brine in the salt cavern, a heat and mass transfer model between oil/brine and the cavity wall of the rock salt cavern and a creep contraction model of the salt cavern cavity are established in this paper. These models are based on thermodynamic theory, percolation theory, and creep theory. The combined model is further validated against measurement data collected from rock salt cavern oil storage reservoirs in other countries. With this model, the stability of the oil storage cavern can be explained, and the impacts of typical projects, as described in the Jintan oil storage reservoir development report, can be analyzed. Furthermore, optimal control strategies for the oil storage reservoir under different operating conditions are obtained. The developed model, together with the analytical results, can provide technical guidelines for the construction and operation of a salt cavern strategic oil storage reservoir.