Identification of dominant seepage channels in fractured rock masses of underground water-sealed oil storage: a case study

Identification of dominant seepage channels in fractured rock masses is one of the main challenges to ensure the safety of water-sealed oil storage caverns and reduce water inflow in the caverns. Based on the testing of a water curtain system and discrete element modeling, an identification method for the dominant seepage channel is developed. In this method, the dominant seepage borehole is defined by the seepage characteristics of high permeability, good connectivity, and preferential seepage. Furthermore, the discriminant criterion for these three characteristics is established. The identification method is applied to an underground water-sealed oil storage project. The dominant seepage borehole is identified, and the location of the dominant seepage channel is predicted. In addition, the identification results are verified by statistical data of high-groundwater flow rate areas in the oil storage caverns. The verification results show that 86.7% of the dominant seepage channels predicted by the identification method match the high-groundwater flow rate areas in the surrounding rock fracture of the oil storage cavern, which demonstrates the effectiveness of the proposed identification method. The results can provide useful references for similar underground water-sealed oil storage projects in the identification of dominant seepage channels in fractured rock masses.

Automated summary

This study developed an identification method for dominant seepage channels in fractured rock masses and applied it to an underground water-sealed oil storage project. The verification of the identification results demonstrates the effectiveness of the method, providing valuable references for similar projects in the design and operation.