Adjusted models for aquifer thermal energy storage (ATES) systems simulations

ATES systems can be coupled with various types of building facilities providing heating, cooling and thermal energy storage. The thermal performance and dynamical simulations of ATES systems should be provided based on local structural and parametric framework.

A static model, which can correctly represent the geological nature of the reservoir, is necessary in order to achieve a reliable evaluation and assessment through numerical simulations.

Recent 3D static geomodels from petroleum exploration built for R&D purposes of Department of Energy Resources AGH University of Krakow were adjusted for further geothermic and energy storage fields (ATES, CO₂ sequestration) purposes.

These parametric geomodels are very complex, handling large quantities of input data. A typical static modelling workflow comprises 6 main phases of modelling, starting from database building, through structural modelling, facies modelling, petrophysical modelling, up to volume and reserves calculations and risk assessment.  

One of the examples is a performance simulation of ATES in the Lower Cretaceous reservoir in Central Poland, where a regional Petrel© static parametric model was prepared prior to dynamic simulations in Feflow© software. A methodology of fitting Petrel’s structural and parametrical model to Feflow requirements were prepared.

The basic surfaces constraining the geometrical framework of the dynamic model — in particular top and base on the Lower Cretaceous — were extracted from the regional model. The square part of this model was extracted and subsequently converted into formats applicable in Feflow©. Further assumptions were made for geological and thermal parameters.

In result, the ATES systems can be simulated as a doublet of multilayer wells, which applies a pre-defined extraction or injection nodes along a well screen. The dynamic model was divided in sub-layers of variable thickness. The porosity in the Lower Cretaceous formations was set according to geological static

model. The thermal model of the area was then validated and compared with the geological static model. The performance of ATES simulation was conducted for 30 years according to its specific demand profile.