Abstract: Underground petroleum storage caverns with the containment of groundwater is one of the methods for storage of petroleum. In the construction process of large water sealing petroleum storage caverns, the appearance of engineering excavation changes the surcharge, runoff and drainage conditions of the local groundwater and disturbs the equilibrium of groundwater seepage field. To ensure the water sealing effects, it is necessary to research the fractured rock mass permeability characteristics and space-time evolution behaviors of groundwater seepage field around underground storage caverns. In the engineering background of the first under-construction large water sealing petroleum storage caverns in China, the three-dimensional groundwater numerical simulation is performed using the method of equivalent continuum and permeability tensor theories combined with analysis of in-situ test data. Under anisotropic conditions, groundwater level change is predicted during different construction progresses. The analysis and prediction results show that groundwater level drops and some zero-water head regions appear when excavation is performed without water curtain; the water sealing effects cannot be guaranteed. During operation period, groundwater table rises to 35 m and tends to be stable. The water sealing system is verified. The studied results have theoretical value and important guidance for water sealing evaluation of underground petroleum storage caverns.

Key words: underground water sealing petroleum storage caverns, numerical simulation, anisotropy, seepage field, water sealing