Investigating the role of natural tracers in subsurface CO2 storage and monitoring

Lead Research Organisation: University of Edinburgh
Department Name: Sch of Geosciences

Abstract

Since the Industrial Revolution, burning of fossil fuels (coal, oil and gas) has greatly increased the carbon dioxide (CO2) content of the atmosphere. The higher level of CO2 is widely accepted to be a major contributor to greenhouse warming of the Earth and acidification of the oceans. The effects of this warming on the world are still controversial. However, many scientists now believe that the Earth's atmosphere will heat up by at least 2 to 3 centigrade over the next 100 years. The effects of this warming include rising sea levels, melting of the polar icecaps and increasing risks of severe weather events such as hurricanes. To try to limit this warming to 2 centigrade, governments from the EU and around the world are looking at ways of reducing CO2 emissions. One of the major sources of CO2 is the generation of electricity. Worldwide fossil fuel burning produces 85% of the world's electricity. In the next 10-20 years, it will be difficult to reduce the use of fossil fuel for electricity generation. Renewable energies need time to be introduced and developed, and the world also needs extra methods of generating electricity to safeguard against shortages of intermittent renewable energy - for example, when the wind does not blow enough to turn windmills. It is now possible to burn fossil fuels, and capture the CO2 at power stations, or other concentrated emission sites such as cement works and oil refineries. This CO2 can then be pressurised to liquefy it, and pumped through pipelines to places where the liquid CO2 can be injected underground to be stored. This particular proposal examines some of the controls which affect how CO2 is stored underground and how any leakage out of a reservoir, or to the surface could be detected. To store CO2 a porous reservoir is needed, overlain by an impermeable seal, such as mudstone which stops the CO2 from escaping and rising to the surface. The CO2 must be stored for a long time (thousands of years) to ensure it does not cause further warming. Unfortunately, the first engineered CO2 storage project has only been operating for 10 years. So to find out more about storing CO2 over a long time we need to look at natural CO2 gas fields. Natural CO2 fields are similar to oil or methane gas fields except they contain CO2. Within these gas fields there is also a small amount of unreactive noble gases. These noble gases have different sources and can be used to work out where the natural CO2 has come from. Recent research has shown that natural CO2 fields from around the world have trapped CO2 for millions of years. This research has also shown that a lot of CO2 is trapped as a result of it dissolving into the porewater within the gas field. This proposal will firstly develop detailed computer models to independently predict how much chemical dissolution into the porewater could realistically occur within the CO2 fields. Several scientists also believe that once CO2 is pumped underground it will crystallise new mineral. This would 'lock' the CO2 into the reservoir and is the most secure form of storage. This work would analyze recent minerals formed within a CO2 field to test if the amount of light carbon (carbon 12) to heavy carbon (carbon 13) was the same as would be expected if the minerals were crystallised from the CO2 stored in the field. The project will also investigate if noble gases can be used to record if CO2 has moved through the mudrock seal from different natural CO2 fields. As CO2 moves through the mudrock it is believed that some noble gases contained in it will be left behind, stuck onto organic debris. In a similar fashion noble gases can also be stuck onto natural coals. This project will test if the noble gases derived from coal burnt in a power station and its produced CO2 exist in large enough quantities to be used to trace the CO2 once it is injected underground.

Publications

10 25 50
 
Description The main output from my fellowship work is a means of testing for CO2 leaks from carbon storage sites. This test will allow the rapid detection of the source of CO2 should a leak from an engineered CO2 storage site be alleged, allowing the allegations to be quickly confirmed or denied. This test was developed by measuring the noble gases contained in CO2 rich waters collected from above the natural St. Johns Dome CO2 field. I determined that a component of the He fingerprint measured in gaseous CO2 sampled from the deep reservoir, could be traced along a fault plane to be present in the waters emerging at the surface above the CO2 field. This result showed for the first time that CO2 can be fingerprinted from source to surface using noble gases.
Exploitation Route The findings from my Fellowship have been used extensively by myself and my PhD students which has resulted in a number of subsequent publications as outlined in the outputs section.
Sectors Energy

Environment

 
Description The main output from my fellowship work is a means of testing for CO2 leaks from carbon storage sites. This test will allow the rapid detection of the source of CO2 should a leak from an engineered CO2 storage site be alleged, allowing the allegations to be quickly confirmed or denied. This test was developed by measuring the noble gases contained in CO2 rich waters collected from above the natural St. Johns Dome CO2 field. I determined that a component of the He fingerprint measured in gaseous CO2 sampled from the deep reservoir, could be traced along a fault plane to be present in the waters emerging at the surface above the CO2 field. This result showed for the first time that CO2 can be fingerprinted from source to surface using noble gases.
 
Description New-Isotope Coupling and Classical tools: Applications to Reservoir and Exploration
Amount £956,000 (GBP)
Funding ID RB0398 
Organisation Total E & P 
Sector Private
Country United Kingdom
Start 07/2015 
End 07/2018
 
Description Noble gas geochemistry: CO2 source and fluid organization
Amount £13,959,800 (GBP)
Funding ID 4300003770 
Organisation Total E & P 
Sector Private
Country United Kingdom
Start 08/2018 
End 08/2022
 
Description UK Carbon Capture and Storage Research Centre 2017 (UKCCSRC 2017)
Amount £6,233,759 (GBP)
Funding ID EP/P026214/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 03/2017 
End 03/2022
 
Description UKCCSRC flexible funding call 2018 project
Amount £195,000 (GBP)
Organisation UK Carbon Capture & Storage Research Centre 
Sector Academic/University
Country United Kingdom
Start 04/2020 
End 10/2021
 
Description Aquistore 
Organisation Petroleum Technology Research Centre
Department Aquistore Project
Country Canada 
Sector Charity/Non Profit 
PI Contribution We have sampled the CO2 being transported inot and injected into the Aquistore CO2 storage site
Collaborator Contribution They allowed us to collect the samples from the pipeline entering the site and the injection well
Impact Samples collected
Start Year 2013
 
Description Cuadrilla 
Organisation Cuadrilla Resources
Country United Kingdom 
Sector Private 
PI Contribution We have collected samples of produced gas from Cuadrilla's Elswick, Preese Hall and Balcombe oil and gas wells for radiocarbon, noble gas, stable carbon and oxygen analysis.
Collaborator Contribution Cuadrilla enabled sample collection by providing site access to the three wells and sites
Impact Samples have recently been analysed and will be presented in an manuscript which is currently under preparation.
Start Year 2013
 
Description Ferrybridge 
Organisation Scottish and Southern Energy (SSE)
Country United Kingdom 
Sector Private 
PI Contribution SSE collected captured CO2 samples from their Ferrybridge Carbon capture pilot plant (CCPilot100+) for us to analyse for noble gases and stable carbon and oxygen isotopes.
Collaborator Contribution SSE collected the samples for us and shipped them for analysis
Impact Samples collected and analysed. Results to be published in a forth coming journal paper
Start Year 2013
 
Description Niederaussem Power Station 
Organisation RWE AG
Department RWE nPower
Country United Kingdom 
Sector Private 
PI Contribution We have collected and analysed the stable isotope and noble gas fingerprint of CO2 captured at Niederaussem Power Station
Collaborator Contribution RWE enabled us to collect the samples and spend a day showing us their caputre facilities
Impact Samples of captured CO2
Start Year 2014
 
Description Total E & P 
Organisation Total E & P
Country United Kingdom 
Sector Private 
PI Contribution The novel use of geochemical tracing tools in the research in this grant led to discussion with an interested contact within Total Exploration and Production. This led to the development of an industrial collaboration with the Scottish Universities Environmental Research Centre, firstly aimed at understanding the connectivity of a UK North Sea hydrocarbon discovery and then on understanding the origin of CO2 in unconventional gases in Argentina. This has recently been followed by a project aimed at applying geochemical tools to constrain the origin of elevated CO2 levels in offshore Brazilian hydrocarbon fields.
Collaborator Contribution New-ICCARE project: Total had realised that isotope coupling had become a powerful tool to constrain the origin of fluids and a robust means to determine the rates of fluid migration in academic studies. However, this had only been applied to large scale geological models, meaning that the existing techniques were unsuitable for inclusion in predictive reservoir models. The over-arching aim of the New-ICCARE project was to incorporate reservoir and thermodynamic modelling into the existing state of the art isotope coupling techniques. UoE scientists evaluated the role that noble gas isotope geochemistry can play in determining the origin of natural CO2-rich fluids contaminating an unconventional field where hydrocarbon production has been stimulated by hydraulic fracturing (fracking), and the development a new method to determine the static reservoir connectivity using noble gases within the Tormore hydrocarbon discovery of the UK North Sea. CO2 source and fluid organisation project: The pre-salt reservoirs of the offshore Brazilian and Angolan Atlantic margins are known to have a complex fluid history. They are composed of a mixture of hydrocarbon fluids and variable amounts of CO2. It is known that this CO2 has a predominantly magmatic source linked to rifting, associated transfer zones, or to mantle plumes. The timing of CO2 charge is dependent on its source and the duration of the related magmatism, which has an important impact on the ability for hydrocarbon fluids to enter reservoirs or spill from them, or be diluted with CO2. The UoE team provided an integration of noble gas tracing constrains to the reservoir fluid charging history (HC+CO2) with basin modelling. Selected samples from pre-salt reservoirs were analysed, and compared to existing fluid databases from the two margins. This showed that the CO2 was unequivocally from a deep mantle origin, allowing the identification of high risk areas where deep crustal faults related to the Atlantic opening intersected with shallow basin related faults.
Impact New-ICCARE Project Impact: The project delivered two significant outcomes. The first of these ascertained the origin and migration pathway of mantle derived CO2 gases that had contaminated an unconventional hydrocarbon play in Argentina, providing a robust estimate of the maximum amount of CO2 that could be encountered in that play. This is significant as any CO2 encountered would be expensive to remove, and would add to the greenhouse gas emissions of the project should it be vented to the atmosphere. The second outcome was a new means to determine static reservoir connectivity using a combination of noble gas isotope coupling and reactive flow modelling from exploration wells. Both of these outcomes have provided new knowledge to assist Total in the responsible exploitation energy resources from both regions. CO2 Source and Fluid Organisation Project Impact: The project has obtained an overview of the absolute charging time and precise origin of the CO2. This will allow the CO2 associated exploration risk for individual areas to be quantified, and will greatly assist in economic exploration of the provinces. This will translate into avoidance of accidental drilling into a high-CO2 accumulation, and as each well in the region costs ~€40M to drill and complete, significant cost savings to the operator are envisaged.
Start Year 2015
 
Description Invited Speaker at British Science Association and EDSci Edinburgh meeting 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact Invited Speaker at British Science Association and EDSci Edinburgh meeting where I presented a talk entitled "Engineering Clean Fossil Fuels for a Decarbonised Future"
Year(s) Of Engagement Activity 2015
URL http://edinburghbsa.weebly.com/lecture-series.html
 
Description Presentation at 12th Greenhouse Gas Control Technologies Conference 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Participants in your research and patient groups
Results and Impact Following my talk at the conference I received a number of questions on my research, both orally in the session itself and afterwards and via email.

After giving my presentation I was asked to present the results of my work at the Gulf Coast Carbon Research centre weekly group meeting at the Bureau of Economic Geology at Austin.
Year(s) Of Engagement Activity 2014
URL http://www.ghgt.info/index.php/Content-GHGT12/ghgt-12-overview.html
 
Description Presentation at ChemEng day, Manchester, April 2014 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Academic researchers and industrial professionals at all levels working within research in chemical engineering and related sectors, particularly those based within the UK attended the ChemEng day at the University of Manchester. I presented a talk entitled 'Opportunities for Engineering Clean Fossil Fuels for a Decarbonised Future' talk which was attended by ~200 delegates. The talk was followed by a panel discussion and I was asked a number of questions on my research in the area.

The chair of the session, President of the IChemE, Geoffrey Maitland reported that my talk had been well received and had promoted discussion following the session.
Year(s) Of Engagement Activity 2014
URL http://www.gnomikos.com/CEDay2014/
 
Description Presentation on CO2 storage - Secure carbon burial for climate mitigation 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? Yes
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact The talk was part of the wider CPD course on CCS and prompted significant discussion afterwards.

Following my talk i was asked by a number of participants of the CPD course to provide more detail on my research activities
Year(s) Of Engagement Activity 2014
URL https://ukccsrc.ac.uk/news-events/events/ccs-cpd-course