Abstract:Taking the geological conditions of a water-sealed petroleum cavern group as an example,a 2D FEM model is established.Based on the saturated unsaturated non-constant flow numerical theory,the effects of permeability coefficient,initial groundwater level and rainfall recharge on the surrounding rock water level of the cavern group are studied.The results show that:(1)The smaller the permeability coefficient of surrounding rock,the less obvious the drop of groundwater level,and the more favorable the formation of water seal conditions;for the rock mass with higher permeability,the initial water level increase has little effect on the formation of water seal conditions. (2)The smaller the permeability coefficient of surrounding rock,the larger the hydraulic gradient around the cave.The hydraulic gradient of the surrounding rock of the caverns on both sides is larger than that of the middle cavern.The initial water level has little effect on the hydraulic gradient of the surrounding rock. (3)Affected by the excavation drainage,the water level of the surrounding rock of the cavern is reduced rapidly,and the rainfall recharge does not have a significant impact on the groundwater level,but the formed suspension saturation zone still has a certain retardation effect on the escape of oil and gas.