Injection and production optimization of Well JZ in Jintan Salt Cavern Gas Storage

Well JZ is the first pilot test well in Jintan Salt Cavern Gas Storage, and so far, it has been put into operation for 5 years. It is shown from the latest cavity measuring with sonar and the mechanical characteristics analysis that the current injection and production pattern of Well JZ can't meet the demand of cavity stability and the roof of the cavity partially collapsed. In this paper, finite element numerical simulation software was applied to conduct injection and production mode optimization and mechanical stability evaluation and analysis on the latest cavity shape of Well JZ. It is indicated that the operation pressure range of injection and production is optimized from the initial 7-17 MPa to the current 10-17 MPa. The dwell time of the minimum operation pressure is quantified, and it shall be not longer than 10 days. The operation of the cavity can be kept safe by conducting 6 peaking shavings each year. It is necessary to control the daily cavity operation pressure drop below 0.5 MPa and keep the gas production rate at 50×10⁴ m³/d. In order to ensure the safe operation and fine management of Jintan Salt Cavern Gas Storages, it is of great significance to optimize the operation pressure range and condition based on different cavity shapes.