Applied Geosciences - Geohydromodelling

Research

Geohydromodelling is the development and application of numerical simulation codes for a characterization of the natural or man-made induced hydraulic, mechanical, thermal and geochemical processes (THMC-processes). Aim is the quanti-fication of the governing processes and their interactions to enhance the process understanding and the prognosis of the induced effects due to subsurface use.

Model development

Model development concentrates on the development and implementation of numerical methods in the open source code OpenGeoSys. OpenGeoSys is an object- and process-oriented scientific software for the numerical solution of coupled multi-field problems (THMC-processes) and hydro-systems. Main area is the simulation of reactive non-isothermal transport processes for one- and multi-phase systems. Current work covers:

  • Methods for the simulation of temperature dependent kinetically limited reactions during degradation of contaminants as well as dissolution or precipitation pf minerals in contact with ground water
  • Methods for the simulation of geochemical equilibrium reactions at high temperature and salinity conditions
  • Coupling of OpenGeoSys and the geochemical simulators PhreeqC and ChemApp
  • Coupling of OpenGeoSys and the reservoir-simulator ECLIPSE (©Schlumberger) for the simulation of large scale reactive multiphase flow
  • Development of detailed models for geothermal heat extractors
  • Implementation and application of methods from high performance computing

 

 THMC

 

Application studies

Aim of the model application studies are the characterization, quantitative description and prognosis of non-isothermal flow and reactive transport process occurring in the subsurface. Applications are both on the laboratory as well as the field and reservoir scale. Application areas are:

  • The detailed simulation of laboratory and field experiments for process characterization, optimization and parameter identification
  • Simulation of energy- (e.g. methane or hydrogen) or CO₂-storage in the subsurface and the induced reactive flow and transport processes and geomechanic effects
  • High resolution simulation of borehole heat extractors
  • Prognosis of ground water contamination and biodegradation processes and of contaminated site remediation
  • Simulation and assessment of monitoring- and site investigation strategies
  • Application of high performance computing methods for reservoir scale simulations

 

tank_square.jpg

Fig.1: Bench-scale experimantal and numeric simulation of solutes in heterogeneous porous media on the laboratory scale (Figure: E. Ballarini, in Ballarini, E., Bauer, S., Eberhardt, C. & Beyer, C., 2014. Evaluation of the Role of Heterogeneities on Transverse Mixing in Bench-Scale Tank Experiments by Numerical Modeling. Groundwater, 52(3), 368–377, doi:10.1111/gwat.12066)

 

co2_portrait.jpg

Fig. 2: Analysis and validation of pressure monitoring in a virtual CO2 storage formation (Figure: K. Benisch, in Benisch, K. and Bauer, S., 2013. Short- and long-term regional pressure buildup during CO2 injection and its applicability for site monitoring. International Journal of Greenhouse Gas Control 19, 220-233, doi: 10.1016/j.egypro.2013.06.260.)

 

Brine vs CO2

Fig. 3: Numerical model of the convection flow in the subsurface induced by the chemical reaction of injected CO2 with brine and parent rock. After 1000 years of  equilibrium reaction, the brine density increases by 23 gl-1 due to salinity  alterations. The model space measures 87.5 m by 35.0 m. The top 10.0 m of the model space are discretized with 0.05 m by 0.05 m, the lower 25.0 m with 0.05 m by 0.10 m (Figure: A.B. Mitiku and S. Bauer).