Reducing greenhouse gas emissions through carbon dioxide storage
Carbon dioxide modelling
Mitigating climate change using carbon dioxide (CO2) geological storage requires the identification of suitable underground reservoirs which will enable CO2 to be stored economically and indefinitely without leakage to the surface.
Carbon dioxide can be stored using existing gas fields that are no longer used for production as well as in deep saline aquifers residing under layers of impervious clays and muds. When storage sites are characterised correctly, in terms of geology, chemistry and physically, storage can be targeted where there is low risk of potential paths to the surface.
CSIRO is developing computer models based on the technology and knowledge that have been used for decades by the petroleum industry to calculate and predict the movement and behaviour of injected CO2.
Understanding the migration pathways of the CO2 plume and trapping mechanisms for CO2 storage are key to reducing risk and identifying suitable storage sites for the future. The models can additionally be used to assess the potential of saline aquifers and depleted reservoirs to be used for carbon storage.
In order to determine whether it is economical and safe to inject and store CO2 at a particular site, the behaviour of the CO2 within the confines of a reservoir needs to be well understood. Data acquired from site characterisation is input into the models.
CSIRO is applying transport modelling to improve the understanding of these issues by:
- providing scenarios of CO2 migration in the reservoir
- assessing the CO2 injection strategy at different sites, providing input for evaluating the associated economics.
TOUGH2 is a multi-phase porous media solver developed by Lawrence Berkeley National Laboratory (LBNL) which is well suited to modelling the complex transport phenomena involved in CO2 subsurface migration.
CSIRO staff work closely with the LBNL to make modifications to improve the understanding of all the fluid behaviour in the subsurface.
Our research capabilities enable us to:
CSIRO is developing computer models that predict the fate of injected carbon dioxide.
- improve the fundamental understanding of phenomena that occur in CO2 storage, via numerical modelling with TOUGH2
- understand gravity currents in porous media with both homogenous and multiple layer (heterogonous) permeability
- validate modelling efforts using both laboratory scale experiments and analytical theoretical studies of gravity currents
- design CO2 well testing, which aims to measure residual saturation of particular reservoirs. Numerical simulation with TOUGH2 is used to assess the well test sensitivity to unknown reservoir characteristics, which can make the calculation of residual saturation difficult.
- apply modelling to simulate site specific reservoirs using static geo-models as input, in order to achieve short and long term likely storage outcomes
- demonstrate the 1000 year safe storage and plume migration in future storage sites.
This research will improve the understanding of CO2 migration behaviour in a general context, whilst applying the models on a case by case level.
The outcome of this research will enable the suitability of sites for CO2 storage to be assessed based on the specific geology of each site.
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Meet some of the team working in carbon dioxide modelling: