OpenGeoSys Summer School 2019

Environmental Geotechnics

29.08-06.09.2019, Hangzhou, China

Schedule (tentative)

Module description

Porous Media Mechanics (Thomas Nagel)

Contents: At the beginning of the course, the theoretical foundations of OGS will be revisited. These include the Theory of Porous Media as a continuum mechanical framework for modelling multiphysical problems in porous multiphase materials. Going from general theory to specific coupled problems we will highlight the treatment of solid and fluid mechanics in environmental geotechnics as well as heat transport coupled to reactive solid-gas interactions in energy storage applications. The finite element method used for solving such problems in OGS will be reviewed along with schemes for time integration and process couplings. The teaching will involve both theoretical concepts and equations, but also show where to find and how to read these equations in the OGS source code. 

Geomechanics (Thomas Nagel / Ning Zhang)

Contents: After the general introduction, a special focus will be put on introducing a general interface for material models for solids. The integration of inelastic constitutive models in implicit finite element software such as OGS will be discussed and illustrated on elasto-plastic as well as visco-plastic material models. Some specific models used for the simulation of rock salt behaviour will then be introduced and form the basis for the subsequent exercised using OGS. The users will see how to set up and run mechanical and thermo-mechanical analyses of rock salt using OGS for applications in nuclear waste disposal as well as gas storage in salt caverns for energy storage applications.

OGS Development (Olaf Kolditz / Wenqing Wang)

Contents: The main part of the training course is about using OGS for applications in environmental geotechnics such as geothermal energy, nuclear waste management, and energy storage in the subsurface. In addition we will also give an insight and overview of the OGS development concept and platform. This should enable the course participants to become an active part within the OGS developer community.
This course part includes:
- Setting up OGS development environment (Git, CMake, Conan etc.)
- OGS compilation (also on parallel computing infrastructure)
- OGS benchmarking procedure
- OGS documentation
We will also explain the novelty of the OGS-6 framework and the transition process from OGS-5 towards the new platform.

DECOVALEX (Wenqing Wang / Olaf Kolditz)

Contents: Coupled thermal-hydraulic-mechanical (THM) processes in the host rock of nuclear waste repositories or in geothermal reservoirs are the common phenomena. These phenomena have to be well investigated for the safety of nuclear waste repositories or for the production efficiency and the life span of the geothermal reservoirs. Such investigation can be performed by the means of experiments and numerical modelling. The experiments, which mock the real facilities, are normally conducted in the small scale level within a limit period due to their huge costs. Then the numerical methods are applied to simulate the experiments in order to calibrate the material properties of the host rocks and validate the applied numerical models. At the end the coupled THM processes in the real applications can be predicted by the numerical simulations with calibrated material properties and the validated numerical models. This is exactly the purpose of the DECOVALEX (Development of Coupled Models and Their Validation Against Experiments) project, and this is also the charming of the numerical modelling.
In this course we will introduce
1. the mathematical theory of coupled THM processes,
2. the finite element method for coupled THM processes,
3. how to use OpenGeoSys to simulate the coupled THM processes with a simple 2D THM example about a real nuclear waste repository described in Step 4 of Task E of the DECOVALEX 2019. With the example, we will also introduce how to conduct parallel computing by using OpenGeoSys.

Geothermal Systems (Haibing Shao)

Contents: As geothermal energy is increasingly utilized as a renewable and low-carbon energy source, numerical tools are increasingly utilized to characterize and quantify coupled processes in geothermal reservoirs. In this context, the training course will be divided into two parts, one for the shallow geothermal utilization, and the other for high-enthalpy geothermal exploration process.
In the first day, theory of heat transport in porous and fractured media will be introduced. The governing equations Borehole Heat Exchangers will be explicitly explained. A practical numerical model on shallow geothermal energy extraction will be introduced and simulated with the OpenGeoSys software. Analysis will be conducted to quantify the amount of sustainably extractable geothermal energy. Attendants of the lecture will be given specific questions to be solved with the numerical tools at hand. In the second day, the lecture will focus on the development of high-enthalpy geothermal reservoir for electricity productions purposes. The fundamental theory of steam table and geothermal power generation system will be introduced. The lecture material will also cover the general work flow of reservoir engineering and development. Attendants will be given a series of exercises to help understand this development process.
Both part of the training program will intensively be coupled with numerical simulations on the OpenGeoSys platform. Attendants are expected to bring their own laptops to construct and simulate coupled processes in geothermal reservoirs.