Giant, halite-dominated salt accumulations are common on Earth. Throughout the human history, they have been mined for their salt that was used for animal nutrition, food conservation, de-icing etc. Compared to the other rocks, halite itself is quite a peculiar material characterized by:
- a low density;
- a low permeability;
- a high solubility in water and;
- a high thermal conductivity.
In response to long-term geological stress, it undergoes plastic deformation, in other words it flows, within a more brittle subsurface. This results in complex geological structures that have drawn the attention of the oil and gas industry in the 20th century (you can see here a brief history of salt tectonics). Its properties mentioned previously make halite layers an excellent seal against fluids migration.
The structures shaped by salt tectonics provide traps where the fluids accumulate, allowing the formation of a fluid reservoir. If nowadays these reservoirs are primarily investigated for oil and gas resources, they can also be used for underground storage of CO2, nuclear wastes, compressed air and hydrogen energy storage, which are coming increasingly important topics for the energy transition.
The structures shaped by salt tectonics provide traps where the fluids accumulate, allowing the formation of a fluid reservoir. If nowadays these reservoirs are primarily investigated for oil and gas resources, they can also be used for underground storage of CO2, nuclear wastes, compressed air and hydrogen energy storage, which are coming increasingly important topics for the energy transition.
