Abstract:The changes in the global climate and their far-reaching consequences for the
world population are gaining increasing public, political, and scientific attention.
Several methods for reducing the emissions of the main greenhouse gases
carbon dioxide (CO2), methane (CH4), and laughing gas (N2O) are being
considered. Injecting and storing the most important greenhouse gas CO2
in deep geological formations (e.g. aquifers, exploited gas and oil reservoirs)
is one option that is being discussed seriously.
The application of this method, also called CO2 sequestration, raises questions,
many of which are still open:
- Which problems can arise during the injecting process of carbon dioxide in
deep geological formations?
- What preconditions are necessary to guarantee long-term storage?
- How does the CO2 migrate in which geological conditions?
- Which effects can fractures, faults, or wells have on CO2 storage?
- What is the storage capacity of a given CO2 reservoir?
To carry out estimations and answer these and other questions, it is necessary
to develop physical-mathematical model concepts for the processes that take place
in the subsurface. In this connection, the following aspects are significant:
- Description of the CO2 fluid properties.
- Description of the properties of the multiphase multicomponent system
(brine, CO2) based on thermodynamic theory.
- Taking into account the occuring phase states and corresponding primary
After the physical-mathematical model concept has been developed, it has to be
transformed into numerical algorithms. It is planned to extend the program
MUFTE_UG by the properties mentioned. Subsequently, the model concept will be
checked by carrying out simulations.
In this project, a final step is to be the analysis and assessment of the
influence of physical parameters (porosities, permeabilities, capillary
pressure-saturation relationships, etc.) on the processes during CO2 injection
and storage in geological formations.