Hydrogeological monitoring of mined rock storages
The purpose of the hydrogeological monitoring of operational storage facilities is to check that the hydrogeological conditions required to hydrodynamically confine the stored product are permanently met.
The monitoring process has two aspects:
- the short term: a descriptive approach (curves showing the monitoring parameters) and daily checks of the tightness criterion of the storage facilities.
- the medium-long term: an interpretative approach using graphs showing the criteria calculated using the measured parameters (piezometric levels, hydraulic potential of the pressure cells in the rock, operational data of the storage facilities, data on the influence of external factors). By examining these calculated criteria, it is possible to keep track of the long-term hydrogeological conditions around the storage facilities and to prevent any phenomena that could ultimately endanger the safety of the works. These phenomena include mainly the effects of plugging or unplugging in the rock around the caverns or in the water curtains.
The data required for monitoring purposes and the parameters are available at all times in a database containing the history of each storage facility.
Monitoring the hydraulic overload in the life cycle of the storage facilities.
The data required for monitoring purposes and the parameters are available at all times in a database containing the history of each storage facility.
Geometric parameters of the pressure cells. By calculating this indicator and comparing it with other indicators, it is possible to keep track of the hydrogeological characteristics in the rock around the storage facilities.
In addition to the long-term monitoring of the water tightness of storage facilities, Geostock also provides other services, such as:
- the definition and supervision of the diagnostic and maintenance of the piezometric monitoring networks,
- diagnostic studies of the hydrodynamic tightness devices on existing storage facilities,
- the definition and supervision of works to improve the hydrodynamic sealing devices,
- training in the hydrogeological monitoring of storage facilities for operators and site managers,
- the development of digital models to understand the impact of the storage facilities on their environment (in particular when they are located in the vicinity of other industries using the water resources) or to check whether the operating parameters can be changed.
Modelling of two underground storage caverns by the Feflow® (DHI-WASY) software to identify and quantify plugging phenomena in the water curtain boreholes and the roofs of the caverns.
- development of hydrogeological models of the caverns using the construction data.
Example of a hydrogeological model of a storage facility (from Goldschneider Alexandra, Morruzzi Justine, Bodin Jean-Luc, Amantini Eric, Vaskou Philippe (2009) ; Coupled geological and hydrogeological models in fractured systems: understanding interactions between underground storages and their rockmass, Hydroinformatics in hydrology, hydrogeology and water resources, International Association of Hydrological Sciences. Joint convention, Hyderabad , INDIA, vol. 331, pp. 449-458)