Abstract: The reserve in underground gas storage is one of the key factors enginners take into consideration in designing the gas storage. Guided by exsting gas reservoir theory, a new and suitable for general condition method is put forward aimed at the limitation of calculating dynamic reserve method, including materialbalance method, productivity decline method and unstable well test analitical method, first, from analyzing the lithologic stress of cover rocks in the gas storage, the breaking pressure of the rocks is calculated (i.e., the limit pressure when the storage contains gas), the maximum storing pressure of the storage is 0.7～0.8 times of limit pressure, so the maximum reserve and dynamic reserve of the storage can be determined, case study indicates the method is operable, a new idea is presented to determine the reserve of the storage.

Key words: underground gas storage, effective stress, fracture pressure, reserve, original formation pressure