Gas leak loss and dynamic monitoring determination of underground gas storage

It is important to take close observation over the gas inlet and outlet process or leak of gas storage and verify gas preservation in the storage for gas production and injection operation of underground gas storage to ensure gas supply capacity. This paper analyzes the possible leak loss of gas storage including internal and external leak, and leak loss caused by increasing cushion gas quantity, and emptying of injection well, surface pipeline, equipment or gas production and injection system, and also describes the dynamic monitoring on injection process of current gas storage. It is pointed out that such dynamic parameters as pressure and temperature of gas production and injection well need to be recorded. Besides, monitoring the sealing performance of gas storage cover, well cementing quality and casing sealing performance are necessary. The paper briefly introduces such monitoring methods for gas storage as neutron logging, temperature logging and rotor flowmeter and proposes the dynamic monitoring on gas leak by observing changeable shut-in pressure and pressure changes with gas storage, which provides the theoretic foundation and technical support to the engineering practices of China's gas storage.