Design of water curtain control system of underground water seal oil cavern

Widely building of the large span underground water seal oil caverns must gradually propose more stringent requirements of the design level of oil caverns. The large span underground water seal oil cavern not only needs to rely on the natural conditions of the buried groundwater, but must also relies on the water curtain hole installed around the cavern in a certain pressure to provide a stable water injection pressure to prevent oil leakage. The normal water curtain system can be improved to function more powerfully and economically. The improvement benefits from the theory of flow closed loop proposed and critical storage pressure given according to the theory. Details of the new water curtain system layout and its variable function according to requirement alternation are described. Taking a large domestic underground oil cavern as an example, comparison of seepage of fractured rock of different design is analyzed under the three-dimensional stress field using FLAC3D codes. Combining the relationship between the effective stress of infiltration formation and water pressure around the caverns, the analysis proves that the new layout not only meets the demand of water sealing effect and prevents oil leakage while reducing cavern inflow, but also improves the rock stability and engineering emergency safety.