ProSalz

in Germany, salt deposits are particularly important as an industrial raw material and energy store. However, in active potash and rock salt mining, contact with groundwater in the area of geological fault zones can lead to the formation of cavities in the salt rock. These pose a considerable risk. Fluids migrate through faults into the salt rock and cause a loosening of the rock formation through leaching. This can lead to subsidence with considerable damage to the protected material above ground and the mine building. The aim of the ProSalz project was to improve the process understanding of reactive multiphase transport in the transition zone between cavernous structures and solid rock.

UGS GmbH partnered in a BMBF-supported research project to improve understanding of cavern development in challenging geological conditions. No direct observations of the fluid-salt rock transition zone are possible in caverns. Comparable structures in mining operations therefore served as analogues for investigating processes in the salt rock. Extensive field and lab geochemical and geophysical measurements were conducted. Models were then created on various scales, and sensitivity analyses were carried out in geochemical and hydrodynamic parameter space. With the help of the measurement data obtained, it was finally possible to create and calibrate more complex models in order to map both the chemical and hydromechanical behaviour of cavernous structures and assess their mechanical stability.

The project results were of particularly relevant to both science and industry. Reliable forecasts are essential for the expansion of new energy storage technologies in the course of the energy transition – from construction and operation to the long-term storage of salt caverns. In potash and salt mining, better process insights enhance exploration and predictions of fluid intrusions and saline spread.

More information can be found at ProSalz: GFZ and EGU2018-10314.pdf

Project duration: 1 July 2017 to 30 June 2020

Project management/funding body: Projektträger Jülich/Federal Ministry of Education and Research (BMBF)