Rock salt behavior: From laboratory experiments to pertinent long-term predictions

In the energy transition context, salt caverns are probably the most promising storage solution that promotes the development of intermittent renewable energies, due to their flexible and high deliverability. However, their design is still challenging since it should account for their entire lifetime, from rapid cycling exploitation to centuries of abandonment. The key to an optimal design is a constitutive model for rock salt that ensures pertinent short and long-term predictions. In this paper, we confront the results of five experimental campaigns conducted on different salts with existing rheological models. This confrontation proved that the studied models are capable of describing laboratory tests, however their predictions for the long term are either too conservative or overly optimistic. In practice, conservative or optimistic approaches do not ensure the optimal design of the facility. For this reason, we propose a new constitutive model that provides pertinent long-term predictions while interpreting satisfactorily short-term and long-term laboratory tests.