Determination of operating pressure limit for injection-production cycle of salt-cavern gas storage in Huai'an City

Based on experimental results of physical mechanical parameters for rock salt of storage area in Huai'an City, Jangsu Province, stratigraphic information and design shape information of gas storage, pressure gradient principle and relevant technical regulations are used to determine initial value of the upper and lower limits for internal pressure. Then FLAC 3D software is used to conduct constant pressure rheological analysis and analogue simulation for overall process of internal pressure change in the salt-cavern injection-production cycle. By analyzing the simulation law of maximum principal stress and volume shrinkage in the salt-cavern and comprehensively considering analog computation results and relevant foreign experience, it is suggested that taking 12 MPa to 26 MPa internal pressure for injection-production cycle of the typical well in Huai'an storage area is available. The research results will provide a certain reference to the gas storage operation and assessment in long-term stability of complex underground large buried depth salt-cavern gas storage.