A Review of Evaporite Beds Potential for Storage Caverns: Uncovering New Opportunities

Salt caverns serve as underground storage for crude oil, natural gas, compressed air, carbon dioxide, and hydrogen. Key stages of cavern development for storage purposes include design, construction, storage, and abandonment. The design phase addresses optimal cavern shape, size, pillar dimensions, number of caverns, the impact of interbeds, and cyclic loading while considering the creep behavior of salt and the mechanical behavior of surrounding layers. During this phase, geological factors such as depth, thickness, and the quality of salt are considered. For construction, two main methods—direct leaching and reverse leaching—are chosen based on design specifications. The storage stage includes the injection and withdrawal of gases in a cyclic manner with specific injection rates and pressures. After 30 to 50 years, the caverns are plugged and abandoned. The geological limitation of salt domes makes it essential to look for more bedded evaporites. This study provides a comprehensive review of bedded evaporites, including their origin and depositional environment. The stability of caverns in all these stages heavily relies on geomechanical analysis. Factors affecting the geomechanics of bedded salts such as mineralogy, physical properties, and mechanical properties are reviewed. A list of bedded evaporites in the U.S. and Canada, including their depth, thickness, and existing caverns, is provided. Additionally, this study discusses the main geomechanical considerations influencing design, solution mining, cyclic loading, and abandonment of caverns in bedded salt caverns.