Assessing the water-sealed safety of an operating underground crude oil storage adjacent to a new similar cavern – A case study in China

Siting a new underground water-sealed crude oil storage adjacent to an existing one is a potential way to increase the capacity of strategic energy storage. The study presented herein is a comprehensive case study to assess the water-sealed safety on this topic using monitoring data and numerical analyses. A three-dimensional geo-hydrological model was built based on a specific project calibrated using field monitoring data. The influence of the new construction on the water-sealed safety of the operating cavern was examined with numerical models by considering the effects of the layout of the new cavern. Three indicators were used to quantitatively assess the water-sealed safety of the operating cavern. The result shows that it is feasible to set a storage cavern adjacent to an operating one. The safety separation distance between two projects without a vertical water curtain can be set to 200 m. In addition, vertical water curtain was discussed to shorten the safety separation distance in practical (e.g. with site conditions limitation). The achieved results can be used to guide the design and construction of similar projects.