Refine
Document Type
- Article (17)
- Other (4)
- Monograph/Edited Volume (1)
- Postprint (1)
- Review (1)
Is part of the Bibliography
- yes (24)
Keywords
- PHREEQC (6)
- reactive transport (6)
- digital rock physics (4)
- elastic properties (3)
- heterogeneity (3)
- micro-CT (3)
- numerical simulation (3)
- Code_Aster (2)
- Mont Terri (2)
- carbon dioxide (2)
Institute
- Institut für Geowissenschaften (24) (remove)
The computational costs associated with coupled reactive transport simulations are mostly due to the chemical subsystem: replacing it with a pre-trained statistical surrogate is a promising strategy to achieve decisive speedups at the price of small accuracy losses and thus to extend the scale of problems which can be handled. We introduce a hierarchical coupling scheme in which "full-physics" equation-based geochemical simulations are partially replaced by surrogates. Errors in mass balance resulting from multivariate surrogate predictions effectively assess the accuracy of multivariate regressions at runtime: inaccurate surrogate predictions are rejected and the more expensive equation-based simulations are run instead. Gradient boosting regressors such as XGBoost, not requiring data standardization and being able to handle Tweedie distributions, proved to be a suitable emulator. Finally, we devise a surrogate approach based on geochemical knowledge, which overcomes the issue of robustness when encountering previously unseen data and which can serve as a basis for further development of hybrid physics-AI modelling.