For power and flow calculations in ThermoGIS for geothermal energy, DoubletCalc1D is used. For HT-ATES, however, 3D (buoyancy) effects play an important role, which is why DoubletCalc3D is used for ThermoGIS-HT-ATES. DoubletCalc3D is a software developed by TNO that calculates how much water can be pumped at a given pumping capacity, for a given doublet and subsurface in 3D. It uses a simple (layered) subsurface model and a standardised doublet. DoubletCalc3D (including the GUI called ROSIM) is currently available on request via: rosim@tno.nl The figure above shows the ROSIM-DoubletCalc3D subsurface model in ThermoGIS-HT-ATES. The properties of the clay layers are fixed. The properties of the storage aquifer are based on the input maps.
The table below shows the values for the properties of the storage aquifer and clay layers. The values for rock matrix conductivity (4 W/mK), water thermal conductivity (0.6 W/mK), water density (1000 kg/m3) and rock density (2700 kg/m3) are the same for all cells.
| Depth (m-NAP) | Thickness (m) | Perm xy (mD) | Perm z (mD) | Temperature (°C) | Porosity (%) | Net-to-gross (-) | Salinity (ppm) | |
|---|---|---|---|---|---|---|---|---|
| clay layer overburden | top depth aquifer - 100 | 100 | 20 | 2 | 11 + depth * 0.34 | 0.1 | 1 | 70000 |
| storage aquifer | <input grid> | <input grid> | <input grid> | perm xy * anisotropy (user input) | <input grid> | <input grid> | <input grid> | 70000/1500 × depth |
| clay layer underburden | bottom depth aquifer + 100 | 100 | 20 | 2 | 11 + depth * 0.34 | 0.1 | 1 | 70000 |