Seawater intrusion into an underground water-sealed oil storage cavern: Effects of water curtain system, hydraulic conductivity and dispersivity

Abstract

The construction of underground facilities in coastal area usually results in seawater intrusion, which affects the service life of underground facilities. Considering the effects of different water curtain systems, hydraulic conductivity, and dispersivity, the dynamic seawater intrusion characteristics of an underground water-sealed oil storage cavern in coastal area have been obtained by numerical simulation based on multi-physical field coupling theory. The results show that in terms of the extent and scope of seawater intrusion, compared with only setting horizontal water curtain, adding vertical water curtain is more effective in controlling seawater intrusion; as the depth of the vertical water curtain increases, the effect of preventing seawater intrusion is better. When the equivalent hydraulic conductivity is the same and the anisotropy ratio of hydraulic conductivity increases, the extent of seawater intrusion is weaker; when the anisotropy ratio of hydraulic conductivity is the same and the equivalent hydraulic conductivity increases, the extent of seawater intrusion is weaker. As the longitudinal dispersivity becomes larger, the extent of seawater intrusion is weaker. The water-sealed safety and water inflow of the underground water-sealed oil storage cavern have been analyzed. The research results could provide a theoretical basis for the seawater intrusion problem faced by the construction of underground water-sealed oil storage caverns in coastal area, and have a certain guiding effect on the excavation of underground facilities in coastal area.