Project activity Carbon (CO2) Storage in Residual Oil Zones
Geoscience Australia, in collaboration with CSIRO, is conducting a 4-year study under the Exploring for the Future Program (2020-24) to investigate the potential for carbon (CO2) storage and CO2 enhanced oil recovery (CO2-EOR) in residual oil zones (ROZ) in Australia.
This study will unlock new CO2 geological storage opportunities and accelerate the deployment of carbon capture and storage (CCS) technologies in Australia, supporting our transition to net zero by 2050.
CO2 enhanced oil recovery involves the injection of CO2 into a near-depleted oil field or residual oil zone to help produce some of the remaining oil. Some CO2 is produced with the oil and recycled while the remaining volume of CO2 is stored in the reservoir (Figure 1).
Around the globe, CO2-EOR projects have been injecting and storing CO2 for some 6 decades and are currently responsible for achieving much of the world’s CO2 storage in geological formations. CO2-EOR projects benefit from geological knowledge of the storage site, use of existing infrastructure, and dedicated financial incentives that can be used to offset the costs of CO2 capture, transport and storage in the early days of CCS deployment. With the appropriate settings, CO2-EOR can result in larger volumes of CO2 injected and stored than is emitted from the life cycle of any additional oil produced. CO2-EOR projects demonstrate the feasibility of large-scale sustained CO2 injection, storage and monitoring, and can pave the way to purely storage-focussed projects in the future.
Figure 1: An illustration of the CO2-enhanced oil recovery process in a near-depleted oil field. CO2 (white dots) is injected into the oil field to help produce some of the remaining oil (green). Some CO2 is produced with the oil and recycled while the remaining CO2 is stored in the reservoir
Residual oil zones occur in geological reservoirs that contain potentially economic oil resources that can be produced through CO2-EOR (Figure 2) and, importantly, could offer large-scale geological storage capacity, with or without EOR. These rocks can occur beneath or near oil fields or in areas with no conventional oil accumulations but their occurrence and potential CO2 storage and oil resources are not yet well understood in Australia. Aside from the primary driver of accelerating CCS deployment, we consider the potential for incremental oil recovery from CO2-EOR projects to contribute towards domestic energy security and liquid hydrocarbon supply for non-energy purposes (materials produced by oil refineries).
Development of ROZ could be economically beneficial, help to address greenhouse gas emissions, and provide increased energy security through the production of new domestic oil resources.
Figure 2: Residual oil zones can offer a large-scale opportunity for CO2 storage, including through CO2-EOR, with potential oil production of the residual oil from the largely water-saturated reservoir
Objectives
The CO2-Enhanced Oil Recovery (CO2-EOR) in ROZ study aims to:
- Increase Australia’s options for geological storage opportunities.
- Understand the geological parameters and engineering approaches that define a prospective ROZ target and maximise the amount of CO2 stored through CO2-EOR.
- Understand the scale and opportunity for CO2 storage capacity and potential additional oil production through CO2-EOR in ROZ in Australia’s key onshore basins by developing and testing a workflow comprising geological and petrophysical analysis and reservoir modelling.
- Understand the economics of transport and storage of CO2 in Australia to support decision-making around CCS projects, hubs and related resources.
- Identify regions that demonstrate high potential for early-mover CO2 geological storage in depleted fields and ROZ for further investment, research and development.
Completed and current work
We have:
- Completed a targeted review of the international ROZ production industry and the parameters that are most important to developing CO2-EOR in ROZ.
- Developed a geological and petrophysical workflow and used this to identify and characterise residual oil zones in key hydrocarbon-bearing onshore Australian basins.
- Completed preliminary spatially-enabled economic modelling for CO2 transport and storage in Australia. This model is being implemented in a carbon capture, utilisation and storage (CCUS) multi-criteria decision support tool to help advance the development of CCUS studies and attract investment in CCUS in Australia.
- Completed a reservoir modelling study to understand both the behaviour of CO2 in a typical Australian residual oil zone and estimate the amount of CO2 that could be stored.
Reports, papers and datasets resulting from this work are being progressively published (see data and publications below).
For more information on our other work in the area of carbon capture and storage (CCS), please visit the Carbon capture and storage page on the Geoscience Australia website.
Outputs
Collaboration
Important to know
All data produced by Geoscience Australia, including the data from this study, will be made publicly available from the Geoscience Australia's publication catalogue and the Exploring for the Future Data Discovery Portal after quality control and assurance has been performed.
Contact us
General enquiries: 1800 800 173, clientservices@ga.gov.au
Related information
Australia’s Future Energy Resources
This project is evaluating the potential for new energy commodities hosted within sedimentary basins, including oil, natural gas and hydrogen, to support Australia’s transition to a low carbon economy. It will also assess the optimal locations for green and blue hydrogen production, including storage areas.
CO2-EOR+ in Australia: achieving low-emissions oil and unlocking residual oil resources
Tenthorey, E., Taggart, I., Kalinowski, A., McKenna, J (2021)
CO2 EOR-storage methodology in residual oil zones
Tenthorey, E., Kalinowski, A., Seyyedi, M., Jackson, S., Clennell, B (2022)
