大型地下水封石油洞库渗流场时空演化特征研究

地下水封石油洞库是利用饱水岩体密封性进行石油储存的方式。在地下水封石油洞库的建设中，由于工程体的出现，改变了区域地下水的补给、径流和排泄条件，干扰了原来平衡的地下水渗流场，为保证地下石油洞库的水封效果，需进行裂隙岩体渗透特性及地下水渗流场时空演化研究。以国内首个在建的大型地下水封石油储库为工程背景，结合现场试验数据分析，运用等效连续介质的方法，采用裂隙岩体各向异性渗透张量，建立三维地下水数值模拟模型，预测不同施工进程时地下水位的变化。分析预测结果表明：在地下洞室开挖过程中，无水幕条件下地下水位逐渐降低，主洞室部分区域出现零水头压力区，无法保证水封性；模拟运营期水幕巷道施加定水压力，地下水位上升至设计高度35 m且趋于稳定，可以满足水封效果要求。研究结果对地下石油洞库的水封性评价具有一定的工程意义和理论价值。

Space-time evolution behaviour of seepage field around a large underground petroleum storage caverns with groundwater curtaining

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.