| Title | Robust Framework to Evaluate Representative Heterogeneity for the Simulation of Direct-Use Geothermal Systems |
|---|---|
| Authors | Yuan Chen, Guillaume Rongier, Denis Voskov, Alexandros Daniilidis |
| Year | 2026 |
| Conference | World Geothermal Congress |
| Keywords | |
| Abstract | Fluvial clastic sequence is the typical reservoir rock to develop the project of Direct Use Geothermal Systems (DUGS). However, limited and unknown subsurface data bring challenges to accurately characterize the geology of the fluvial depositional environment and to capture the details of the sand body distribution and connectivity. We utilize the process-based modeling (PBM) approach (Flumy) and object-based modeling approach (OBM) (Fluvsim) to develop a robust framework to evaluate the heterogeneity representation of the fluvial depositional environment. An ensemble of geological models with different global net-to-gross ratios (N/G) is created using PBM and OBM. The generated high-resolution models aim to cover a wide range of N/G from 30% to 85% which is typical for Dutch geothermal sediments. Then a static analysis using the Lorenz coefficient and the Dykstra-Parsons permeability values shows a large range of variability for both PBM and OBM models. This wide range of heterogeneity levels leads to a broad variation in system lifetime during 100 years of thermal production. We also find that the OBM and PBM converge to nearly the same distribution of predicted system lifetime when the global N/G is 85%. We find the N/G ratio threshold is between 80% to 85%. Different upscaling techniques are applied to the selected models using both PBM and OBM. Compared to harmonic and geometric averaging techniques, the arithmetic averaging shows better dynamic solutions closer to the fine-resolution results. However, there is inconsistency in production temperature when we apply arithmetic upscaling for both PBM and OBM models. |