Optimisation of water wells improves the efficiency of recharge and energy storage

Flow behaviour in partially-penetrating wells

Maximising pumping efficiency depends crucially on a minimal influence on the hydraulic field during re-injection. Fast High Volume Infiltration (FHVI) wells are increasingly being used for this purpose: partially-penetrating filters with a very limited filter length. In his research, KWR researcher Jan van Lopik compared the flow behaviour around an FHVI well with that around a fully-penetrating well in the same aquifer. He conducted extensive field trials (including the injection of both bromide and heat tracers) and model simulations. In addition, the influence of the nonlinear flow in wells of this kind was mapped out on the basis of column experiments. The flow velocity of groundwater means that turbulent flow is a possibility and Darcy’s law is therefore not applicable.

Photo and schematic representation of field test for a flow field around a FHVI

Optimisation of recovery efficiency

The research also included an investigation of whether multiple partially-penetrating infiltration and extraction filters in a single borehole can improve the recovery efficiency of thermal energy in high temperature storage systems. Numerical simulations in the SEAWAT code for MODFLOW were used to investigate the possibility of preventing the density-driven flow of the infiltrated hot water in this situation. The research showed that major gains in recovery efficiency can be achieved if the well system is designed on the basis of an accurate description of the variability in the vertical permeability of the soil.

Dr. Jan van Lopik receives his doctorate diploma from his promotor at Utrecht University, Professor Ruud Schotting