# A Review of Evaporite Beds Potential for Storage Caverns: Uncovering New Opportunities
## 4 Conclusions and Future Research  
Future energy needs, such as cleaner energy production, secure energy storage, CO\({}_{2}\) emission reduction, and managing demand fluctuations, require expanded options for energy storage. Historically, salt caverns in halite formations have been widely considered for this purpose due to advantages like effective gas containment, self-healing properties, and high deliverability/injectivity rates. Yet halite is not the only evaporite mineral suitable for cavern storage. Other evaporite minerals, such as potash and trona, exhibit comparable behavior. All three--halite, potash, and trona--can be extracted through solution mining, which leaves a cavern for storage purposes. From a geomechanical perspective, these minerals display creep behavior; although, this investigation revealed some differences in the creep behavior among the three. Each mineral is deposited in bedded evaporite form. Despite their similarities, potash and trona deposits have primarily been considered for mineral extraction. The findings of this research suggest an additional advantage for these bedded evaporites--beyond their commercial value--by highlighting their potential for cavern storage, aligning with the growing need for more storage capacity.  
Thus, this review paper underscores the importance of bedded evaporites not previously considered for cavern construction and subsequent storage, specifically potash and trona. It provides a comprehensive overview of evaporites, including their origin, depositional environment, and constituent minerals--factors that influence the physical and mechanical properties of bedded evaporites. To illustrate the potential for cavern development and storage, we present a list of bedded salts, including the number of caverns and their usage in the U.S. and Canada. This paper also reviews key rock properties, particularly those affecting the geomechanical behavior of caverns. Finally, a detailed review of the geomechanics of bedded salts through various stages of design, solution mining, cyclic loading, and abandonment is presented. Additional research on the following topics could further enhance our understanding of evaporite formations and unveil new opportunities for underground gas storage:  
1. Salt caverns have been used for storage purposes due to their unique properties. However, exploring additional evaporite beds, such as potash and trona, could expand opportunities for energy storage.
2. The mineralogy of salt, potash, and trona caverns plays an important role in their physical and mechanical behavior. While the mineralogy of these beds is well understood, more studies focusing on physical and mechanical properties are necessary for broader applications.
3. It is important to understand how different physical and mechanical properties affect solution mining and the stability of caverns in different evaporite beds. Reliable data on density, porosity, and permeability in potash and trona beds are currently limited and should be prioritized.
4. Developing innovative design approaches compatible with the nature of bedded salts will improve storage functionality and practicality.
5. Geochemical aspects, alongside geomechanical factors, are critical for cavern stability and must be considered in the design, operation, and abandonment phases.  
Although this study focused on three evaporite deposit types, future research should address how the characteristics of stored materials influence evaporite properties.
* Investigating geochemical reactions and microbial effects on cavern integrity in different bedded evaporites is recommended, considering the specific mineralogy, type of stored gas, and in situ microbial communities.
* Coupling these geochemical insights with geomechanical consideration will offer a broader perspective on cavern integrity in various bedded evaporites, which is an essential gap to be addressed in future research.