Solving the evolution of carbonate porosity: a dynamic solution for enhanced oil recovery and carbon capture and storage
Lead Research Organisation:
University of Cambridge
Department Name: Earth Sciences
Abstract
Fossil fuels, such as oil, natural gas and coal, provide approximately 80% of the world's energy supplies. During the burning of fossil fuels, carbon is released as carbon dioxide. Carbon dioxide is a potent greenhouse gas: when released into the atmosphere it traps outgoing longwave radiation, called the 'greenhouse effect'. Over the last 250 years, since the industrial revolution, carbon dioxide concentrations in the atmosphere have been increasing, enhancing the greenhouse effect and hence, global warming. An innovative solution to our continued reliance on carbon-based fuels is Carbon Capture and Storage, which seeks to reduce the amount of carbon dioxide released during the burning of fossil fuels by capturing some carbon dioxide and storing it deep underground. This carbon dioxide pumping, or flooding, in deep underground rocks is also used within the oil industry to aid in Enhanced Oil Recovery.
There are many challenges related to storing carbon underground, and one of the most important of these is understanding the chemical reactions it will have with the surrounding rock. When carbon dioxide is injected it dissolves in the pore fluid within the rock. Dissolved carbon dioxide is a weak acid, and can dissolve minerals that are soluble in weakly acidic conditions. This particularly impacts rocks made of limestone, due to the solubility of these carbonate minerals. The dissolution of these minerals creates more space within the reservoir, which allows for the storage of further carbon dioxide, but may lead to reservoir collapse if taken to extreme.
The addition of dissolved carbon dioxide to reservoir rocks can further stimulate microbial activity, which can create conditions favourable to the formation of carbonate minerals. These can be beneficial as they are chemically stable and therefore store the injected carbon dioxide over long time scales. However the formation of carbonate minerals can also lead to the destruction of the network of spaces within the rocks ("porosity"), which makes further injection impossible. The destruction of porosity also leads to the sealing of the reservoir, making the recovery of further fossils fuels impossible.
Our lack of understanding of what happens to carbonate rocks during carbon dioxide injection represents a major gap in our ability to store carbon underground. This fellowship seeks to understand how the addition of carbon dioxide to a carbonate reservoir will stimulate microbial activity, and how this will lead to the generation, or destruction, of porosity. This will be conducted by initially running multiple laboratory experiments to determine how the chemistry of the injected fluid affects the microbial processes within the reservoir rocks. I will use multiple high resolution geochemical tools to track the precipitation or dissolution of carbonate minerals within the reactors. The results from the laboratory experiments will be fed into numerical models, which can be used for predictive purposes, and will identify how changes in the chemistry of the injected fluid and reservoir properties interacts to impact the porosity evolution.
Samples will also be measured from multiple carbonate reservoirs in order to compare the laboratory data to current or potential sites for carbon capture and storage. The numerical models once trained with both the laboratory and field data will be used to create a predictive framework to predict the chemistry of the fluid that should be injected into any potential reservoir for carbon capture and storage, and how the particular fluid will lead to the creation or destruction of porosity, dependant upon the required outcome.
There are many challenges related to storing carbon underground, and one of the most important of these is understanding the chemical reactions it will have with the surrounding rock. When carbon dioxide is injected it dissolves in the pore fluid within the rock. Dissolved carbon dioxide is a weak acid, and can dissolve minerals that are soluble in weakly acidic conditions. This particularly impacts rocks made of limestone, due to the solubility of these carbonate minerals. The dissolution of these minerals creates more space within the reservoir, which allows for the storage of further carbon dioxide, but may lead to reservoir collapse if taken to extreme.
The addition of dissolved carbon dioxide to reservoir rocks can further stimulate microbial activity, which can create conditions favourable to the formation of carbonate minerals. These can be beneficial as they are chemically stable and therefore store the injected carbon dioxide over long time scales. However the formation of carbonate minerals can also lead to the destruction of the network of spaces within the rocks ("porosity"), which makes further injection impossible. The destruction of porosity also leads to the sealing of the reservoir, making the recovery of further fossils fuels impossible.
Our lack of understanding of what happens to carbonate rocks during carbon dioxide injection represents a major gap in our ability to store carbon underground. This fellowship seeks to understand how the addition of carbon dioxide to a carbonate reservoir will stimulate microbial activity, and how this will lead to the generation, or destruction, of porosity. This will be conducted by initially running multiple laboratory experiments to determine how the chemistry of the injected fluid affects the microbial processes within the reservoir rocks. I will use multiple high resolution geochemical tools to track the precipitation or dissolution of carbonate minerals within the reactors. The results from the laboratory experiments will be fed into numerical models, which can be used for predictive purposes, and will identify how changes in the chemistry of the injected fluid and reservoir properties interacts to impact the porosity evolution.
Samples will also be measured from multiple carbonate reservoirs in order to compare the laboratory data to current or potential sites for carbon capture and storage. The numerical models once trained with both the laboratory and field data will be used to create a predictive framework to predict the chemistry of the fluid that should be injected into any potential reservoir for carbon capture and storage, and how the particular fluid will lead to the creation or destruction of porosity, dependant upon the required outcome.
People |
ORCID iD |
Harold Bradbury (Principal Investigator / Fellow) |
Publications
Bradbury H
(2021)
The Carbon-Sulfur Link in the Remineralization of Organic Carbon in Surface Sediments
in Frontiers in Earth Science
Bradbury H
(2019)
Reevaluating the carbon sink due to sedimentary carbonate formation in modern marine sediments
in Earth and Planetary Science Letters
Bradbury H
(2020)
Calcium isotope fractionation during microbially induced carbonate mineral precipitation
in Geochimica et Cosmochimica Acta
Bradbury H
(2018)
The Calcium Isotope Systematics of the Late Quaternary Dead Sea Basin Lakes
in Geochemistry, Geophysics, Geosystems
De Wet C
(2021)
Semiquantitative Estimates of Rainfall Variability During the 8.2 kyr Event in California Using Speleothem Calcium Isotope Ratios
in Geophysical Research Letters
Dutta S
(2022)
A method for a fast and economical in situ collection of pore water in sandy sediments
in Frontiers in Marine Science
Erhardt A
(2020)
The calcium isotopic composition of carbonate hardground cements: A new record of changes in ocean chemistry?
in Chemical Geology
Fotherby A
(2022)
An emulation-based approach for interrogating reactive transport models
Fotherby A
(2021)
Modelling the Effects of Non-Steady State Transport Dynamics on the Sulfur and Oxygen Isotope Composition of Sulfate in Sedimentary Pore Fluids
in Frontiers in Earth Science
Description | Gulf of Aqaba Trace Element Ratios in Porefluids |
Amount | € 15,000 (EUR) |
Funding ID | GoATER-iP |
Organisation | EMBRC, France |
Sector | Public |
Country | France |
Start | 03/2020 |
End | 03/2020 |
Description | Department Seminar for UBC (Canada) |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Postgraduate students |
Results and Impact | Around 40 members of the department including faculty, undergraduate and postgraduate students attend my talk on using numerical modelling and multiple isotope systems to trace carbon cycling. This sparked a good discussion at the end of the talk. |
Year(s) Of Engagement Activity | 2022 |
Description | Departmental Presentation at the University of Cambridge |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | Local |
Primary Audience | Postgraduate students |
Results and Impact | A talk was given during a day of geochemistry talks, on calcium isotope fractionation during bacterially mediated carbonate precipitation. The talk sparked several interesting questions and a short debate on the uses of calcium isotopes to constrain carbonate formation. |
Year(s) Of Engagement Activity | 2018 |
Description | Invited Talk at the University of Illinois |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Postgraduate students |
Results and Impact | An invited talk was given to postgraduate students and post docs at UIUC during a research visit. The talk led to a good discussion into the utility of machine learning in Earth Sciences. |
Year(s) Of Engagement Activity | 2020 |
Description | Invited talk at LoGIC (UCL) |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Postgraduate students |
Results and Impact | I presented a research talk on using reactive transport modelling and multiple isotope systems into the breakdown of organic carbon and the precipitation of carbonate minerals. There was general interest in the talk, and a good discussion occurred at the end of the talk. |
Year(s) Of Engagement Activity | 2021 |
Description | Invited talk for Cambridge Environmental Data Science Group Seminar |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | Local |
Primary Audience | Postgraduate students |
Results and Impact | A talk was presented on using machine learning to study carbon cycling to the environmental data science group. The group was particularly interested in the methodology and discussed how to build upon it and apply it to other areas. |
Year(s) Of Engagement Activity | 2021 |
Description | Meetings with Industrial Partners: Schlumberger |
Form Of Engagement Activity | A formal working group, expert panel or dialogue |
Part Of Official Scheme? | No |
Geographic Reach | Local |
Primary Audience | Industry/Business |
Results and Impact | I have had several meetings with a group of leading scientists including Trevor Hughes and Andrew Meredith from Schlumberger at their Gould Research Centre in Cambridge to discuss the progress of the project, and gain input from industry for the direction of the project. Further meetings are planned over the course of 2019 to discuss the project. |
Year(s) Of Engagement Activity | 2017,2018 |
Description | SaltPanWatch |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Other audiences |
Results and Impact | A joint talk was given with Alec Hutchings at Essex Wildlife Trust to national experts in Salt Marshes about the work that the research group conducts in salt pans. A public engagement project was then conducted over the following months, with the following website created so the public could see the data produced. |
Year(s) Of Engagement Activity | 2019 |
URL | https://www.saltpanwatch.com |