Predicting the fate of CO2 in geological reservoirs for modelling geological carbon storage
Lead Research Organisation:
University of Leeds
Department Name: School of Earth and Environment
Abstract
This proposal is to use natural geological examples to evaluate the fate and ultimate safety of disposing of carbon-dioxide deep underground in geological formations. Separation of carbon-dioxide from power station fuels or exhaust products, and the injection and storage of the CO2 underground in geological formations is an economical and practical way for global society to manage energy supplies while transforming to a low carbon economy. The existence of geological sites where natural carbon-dioxide has remained stored for millions of years suggests removal for more than the 10000-year period needed to protect climate maybe practical and safe. However the processes which govern the fate of carbon-dioxide in brine-filled aquifers are complex and to guarantee the safety and efficiency of the storage it is necessary to be able to predict these over the ~ 10000 year storage period, a time much longer than industry currently models reservoir processes. Many of the processes which operate on supercritical or gaseous carbon-dioxide underground may enhance its storage potential. The buoyant CO2 will dissolve in the formation brines to form denser CO2-saturated brine which will sink. The CO2-saturated brine is relatively reactive but current models suggest that the reactions with carbonate and silicate minerals in the reservoir will ultimately lead to a significant proportion of the CO2 being precipitated as carbonate minerals stored permanently. However the CO2-charged brines may also react with the caprocks which retain the carbon-dioxide and it is not known whether this will enhance the seals by mineral precipitation or degrade them by mineral dissolution. A major limitation in our ability to predict these fluid-mineral reactions is that the reactions proceed slowly at variable rates (days or months to many years) and our knowledge of the reaction rates in real field settings is very limited. This project will study fluids and gasses from natural carbon-dioxide reservoirs and, where possible, from sites where carbon dioxide is being actively injected underground, to determine the rates of the mineral-fluid reactions in natural settings. We will duplicate the reactions in laboratory experiments where it will be possible to study the processes under controlled conditions, study individual reactions from the complex set of coupled reactions which take place in the natural rocks and examine the effects of varying potential rate-controlling parameters. The ultimate objective is to inform site assessment, risk and monitoring for geological carbon storage. The research will benefit other areas of the environmental sciences where rates of kinetically-limited fluid-mineral reactions govern important processes.
Organisations
People |
ORCID iD |
Bruce Yardley (Principal Investigator) |
Publications
Allan M
(2011)
Relation between the dissolution rates of single minerals and reservoir rocks in acidified pore waters
in Applied Geochemistry
Kaszuba J
(2013)
Experimental Perspectives of Mineral Dissolution and Precipitation due to Carbon Dioxide-Water-Rock Interactions
in Reviews in Mineralogy and Geochemistry
Ostertag-Henning
(2014)
GaMin'11 - an International Inter-laboratory Comparison for Geochemical CO2 - Saline Fluid - Mineral Interaction Experiments
in Energy Procedia
Purser G
(2014)
Note: CO2-mineral dissolution experiments using a rocking autoclave and a novel titanium reaction cell.
in The Review of scientific instruments
Rosenqvist J
(2012)
Solubility of carbon dioxide in aqueous fluids and mineral suspensions at 294K and subcritical pressures
in Applied Geochemistry
Rosenqvist J
(2019)
Alkali feldspar dissolution in response to injection of carbon dioxide
in Applied Geochemistry
Description | The work carried out under this grant was intended to investigate the extent and nature of the reactions that might take place in deeply buried sedimentary rocks as a result of the injection of carbon dioxide for Geological Carbon Storage. The work has shown that existing formation waters rapidly dissolve carbon dioxide at the interface between them, but the acidity that results is very rapidly neutralised by reactions with common sandstone minerals. While these processes can be modelled quite well with existing computer models, a major difference for this type of situation is that the waters themselves are already saturated solutions of the rocks, and this changes the nature of the reactions that result and their impact on permeability, compared to a more simple model. |
Exploitation Route | The next stage for developing an understanding of how reactions will affects Geological Carbon Storage projects will be to carry out laboratory and pilot scale studies using appropriate natural rocks that are instrumented to monitor mineral-fluid reactions. |
Sectors | Energy |
Description | Our results have been used to formulate more specific studies of mineral-fluid interactions in geological carbon storage, but only limited further work has been completed to date. The results form part of the wider body of science being developed nationally in the UK to inform further development of carbon capture and storage, and we have participated in meetings of the UKCCS Research Centre to this end. |
Sector | Energy |
Impact Types | Policy & public services |
Description | Lecture to International Conference (California) |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Undergraduate students |
Results and Impact | Presented results from our laboratory investigations to an international audience. Co-authors were Jorgen Rosenqvist and Andrew Klpatrick. |
Year(s) Of Engagement Activity | 2013 |
Description | Visiting Professor (University of Texas at Austin) |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | Regional |
Primary Audience | Professional Practitioners |
Results and Impact | Presented a lecture to the CCS research group in Austin and engaged in extended discussions with members. Also gave related but more general lectures in the geology department |
Year(s) Of Engagement Activity | 2012 |
Description | Workshop Presentation (California) |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Professional Practitioners |
Results and Impact | Co-presented an invited contribution to a workshop on Geochemistry of Geologic CO2 Sequestration. This workshop was organised and led by many of the leading figures in the field and provided an outstanding opportunity to introduce work carried out in the UK. It led to increased interest in our work and an increase in reading and citations of it. |
Year(s) Of Engagement Activity | 2013 |