The anisotropic seepage analysis of water-sealed underground oil storage caverns

• The seepage of water-sealed underground oil storage caverns was studied.
• A analytical method to calculate the anisotropic permeability tensor is presented.
• The direction of permeability can be determined through fracture network simulation.
• The value of permeability can be modified based on field test results.

The analysis of the seepage field in fractured rock mass is very important to the design of an underground oil storage project and must be done in the primary stage. A novel analytical method to calculate the anisotropic permeability tensor of an initial seepage field is presented in this paper. Fracture network simulation and results of water-pressing injection tests are used for the development of analytical method. As an example, the proposed method is used to model initial and subsequent seepage fields of Dalian water-sealed underground oil storage caverns project. The changes in the seepage field during the construction and operation periods are investigated adequately. The results indicate that this design meets the requirements for the groundwater level and the vertical hydraulic gradient, although their distributions in the two periods are different, the proposed method is acceptable for the anisotropic seepage analysis.