ABSTRACT
While salt structures played a central role as traps for hydrocarbons in the oil and gas industry for decades, they also serve as host rocks for salt solution mining, caverns, and other underground storages. Salt rock formations are therefore an important host rock for storing strategic oil and gas reserves, compressed air, and hydrogen and thus an essential part of the energy transition. At the same time, salt formations are currently considered host rocks for the storage of radioactive waste in many countries. Mining processes in the industrial projects mentioned above describe a thermomechanical load and induce stresses in the salt and overburden rocks. The induced stress must be analyzed as it can affect the integrity of the host rock. Together with other natural (e.g., tectonics, glaciation) and anthropogenic (e.g., neighboring caverns) loading events, the behavior of the underground storage becomes even less predictable, and we need the support of thermomechanical models. With the help of these models, we can identify critical parameters and localize characteristic high-stress regions within the host rock. Here, we present an interdisciplinary approach with examples from current studies, in which we include microstructural and lab-scale observations and their uncertainties in the rheological model of the salt rock and compute the stress state for typical salt formations and various scenarios.
