Internationally, the number of carbon capture and storage (CCS) projects has been increasing with more than 61 new CCS facilities added to operations around the globe in 2022, including six projects in Australia (GCCSI, 2022). The extraction of reservoir fluid will be an essential component of the CCS workflow for some of projects in order to manage reservoir pressure variations and optimise the subsurface storage space. While we refer to reservoir fluid as brine throughout this paper for simplicity, reservoir fluids can range from brackish to more saline (briny) water. Brine management requires early planning, as it has implications for the project design and cost, and can even unlock new geological storage space in optimal locations. Beneficial use and disposal options for brine produced as a result of carbon dioxide (CO2) storage has been considered at a regional or national scale around the world, but not yet in Australia. For example, it may be possible to harvest energy, water, and mineral resources from extracted brine. Here, we consider how experiences in brine management across other Australian industries can be transferred to domestic CCS projects.

The Exploring for the Future program Showcase 2023 was held on 15-17 August 2023. Day 3 - 17th August talks included: Geological Processes and Resources Session Large scale hydrogen storage: The role of salt caverns in Australia’s transition to net zero – Dr Andrew Feitz Basin-Hosted Base Metal Deposits – Dr Evgeniy Bastrakov Upper Darling Floodplain: Groundwater dependent ecosystem assessment – Dr Sarah Buckerfield Atlas of Australian Mine Waste: Waste not, want not – Jane Thorne Resource Potential Theme National-scale mineral potential assessments: supporting mineral exploration in the transition to net zero – Dr Arianne Ford Australia’s Onshore Basin Inventories: Energy – Tehani Palu Prioritising regional groundwater assessments using the national hydrogeological inventory – Dr Steven Lewis Assessing the energy resources potential in underexplored regions – Dr Barry Bradshaw You can access the recording of the talks from YouTube here: <a href="https://youtu.be/pc0a7ArOtN4">2023 Showcase Day 3 - Part 1</a> <a href="https://youtu.be/vpjoVYIjteA">2023 Showcase Day 3 - Part 2</a>

The Adavale Basin, home to the Boree Salt, is a potential option for underground hydrogen storage (UHS) due to its close proximity to industrial infrastructure, existing pipelines and significant renewable energy sources. This study builds upon a previously constructed 3D geological model to examine the feasibility of developing salt caverns for UHS. The study integrates well data and regional geology, as well as analyses on mineralogy, geochemistry and petrophysical and geomechanical properties of the Boree Salt. Results highlight that the Boree Salt is predominantly halite (96.5%), with a net salt thickness of ~540 m encountered in Bury 1, and has excellent seal properties. Furthermore, the formation overburden pressure gradient implies favourable conditions for storing hydrogen in the Boree Salt. To illustrate the feasibility of UHS, a conceptual design of a cylindrical salt cavern at depth intervals of 1600 – 1950 m is presented. A single 60 m diameter cavern could provide up to 203 GWh (or ~ 6000 tonnes) of hydrogen energy storage. Further investigation to improve our understanding on the Boree Salt extent is recommended.

<div>This document provides metadata for the gross depositional environment (GDE) interpretations that have been generated in support of the energy resource assessments under the Australia’s Future Energy Resources (AFER) project.&nbsp;&nbsp;</div><div>The AFER projects is part of Geoscience Australia’s Exploring for the Future (EFTF) Program—an eight year, $225 million Australian Government funded geoscience data and precompetitive information acquisition program to inform decision-making by government, community and industry on the sustainable development of Australia's mineral, energy and groundwater resources. By gathering, analysing and interpreting new and existing precompetitive geoscience data and knowledge, we are building a national picture of Australia’s geology and resource potential. This will help support a strong economy, resilient society and sustainable environment for the benefit of all Australians. The EFTF program is supporting Australia’s transition to a low emissions economy, industry and agriculture sectors, as well as economic opportunities and social benefits for Australia’s regional and remote communities. Further details are available at http://www.ga.gov.au/eftf.&nbsp;</div><div>The GDE data sets provide high level classifications of interpreted environments where sediments were deposited within each defined play interval in the Pedirka, Simpson and Western Eromanga basins. Twelve gross depositional environments have been interpreted and mapped in the study (Table 1). A total of 14 play intervals have been defined for the Pedirka, Simpson and Western Eromanga basins by Bradshaw et al. (2022, in press), which represent the main chronostratigraphic units separated by unconformities or flooding surfaces generated during major tectonic or global sea level events (Figure 1). These play intervals define regionally significant reservoirs for hydrocarbon accumulations or CO2 geological storage intervals, and often also include an associated intraformational or regional seal.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</div><div>GDE interpretations are a key data set for play-based resources assessments in helping to constrain reservoir presence. The GDE maps also provide zero edges showing the interpreted maximum extent of each play interval, which is essential information for play-based resource assessments, and for constructing accurate depth and thickness grids.&nbsp;&nbsp;</div><div>GDE interpretations for the AFER Project are based on integrated interpretations of well log and seismic data, together with any supporting palynological data. Some play intervals also have surface exposures within the study area which can provide additional published paleo-environmental data. The Pedirka, Simpson and Western Eromanga basins are underexplored and contain a relatively sparse interpreted data set of 42 wells and 233 seismic lines (Figure 2). Well and outcrop data provide the primary controls on paleo-environment interpretations, while seismic interpretations constrain the interpreted zero edges for each play interval. The sparse nature of seismic and well data in the study area means there is some uncertainty in the extents of the mapped GDE’s.&nbsp;&nbsp;</div><div>The data package includes the following datasets:&nbsp;&nbsp;</div><div>Play interval tops for each of the 42 wells interpreted – provided as an ‘xlsx’ file.&nbsp;</div><div>A point file (AFER_Wells_GDE) capturing the GDE interpretation for each of the 14 play intervals in each of the 42 wells – provided as both a shapefile and within the AFER_GDE_Maps geodatabase.&nbsp;</div><div>Gross depositional environment maps for each of the 14 play intervals (note that separate GDE maps have been generated for the Namur Sandstone and Murta Formation within the Namur-Murta play interval, and for the Adori Sandstone and Westbourne Formation within the Adori-Westbourne play interval) – provided as both shapefiles and within the AFER_GDE_Maps geodatabase.&nbsp;</div><div>&nbsp;</div><div>These GDE data sets are being used to support the AFER Project’s play-based energy resource assessments in the Western Eromanga, Pedirka and Simpson basins.&nbsp;</div><div><br></div>

Carbon capture and storage (CCS) is a central component of many proposed pathways to reach net zero CO2 emissions by 2050. Even under conservative estimates, successful deployment of CCS projects at scale will require a substantial investment in the selection and development of new sequestration sites. While several studies have considered the potential costs associated with individual sequestration projects, and others have evaluated the costs of capture and sequestration in a generic manner, few have examined how regional differences in transport distances and reservoir properties may affect the overall costs of sequestration projects. In this abstract, we outline a new model to assess the costs associated with new carbon sequestration projects. The model evaluates the cost of CCS projects accounting for regional variations in transport distance and cost and well the storage properties of individual reservoirs. We present preliminary results from the modelling tool, highlighting potential opportunities for new CCS projects.

<div>The Carpentaria Basin is a Mesozoic basin located in the northernmost part of Australia and is centered around the Gulf of Carpentaria . It forms part of the Great Australian Superbasin that includes the Eromanga, Surat, Nambour and Clarence-Morton basins to the south, the Laura Basin, to the east, and the Papuan Basin to the north. In a west-east direction it extends for about 1250 km from the area of Katherine in the Northern Territory to the Great Dividing Range in Queensland. A small portion of the basin reaches the east coast of Queensland in the Olive River region. In a north-south direction it extends for over 1000 km from Cape York to Cloncurry, in Queensland. The basin has a total area of over 750,000 km2, comparable in size to the state of New South Wales. From a geographic standpoint the sediments of the Carpentaria Basin occur in three areas: offshore below the Gulf of Carpentaria, onshore to the west in the Northern Territory, and onshore to the east in Queensland. This report focuses on the geology and energy resource potential of the onshore areas of the basin but, to provide a broader understanding of the basin evolution there is, of necessity, some discussion of the geology offshore.</div><div><br></div>

CO₂ enhanced oil recovery (CO₂-EOR) is a proven technology that can extend the life of oil fields, permanently store CO₂, and improve the recovery of oil and condensate over time. Although CO₂-EOR has been used successfully for decades, particularly in the United States, it has not gained traction in Australia to date. In this study, we assemble and evaluate data relevant to CO₂-EOR for Australia’s key oil and condensate producing basins, and develop a national-scale, integrated basin ranking that shows which regions have the best overall conditions for CO₂-EOR. The primary goals of our study are to determine whether Australia’s major hydrocarbon provinces exhibit suitable geological and oil characteristics for successful CO₂-EOR activities and to rank the potential of these basins for CO₂-EOR. Each basin is assessed based on the key parameters that contribute to a successful CO₂-EOR prospect: oil properties (API gravity), pressure, temperature, reservoir properties (porosity, permeability, heterogeneity), availability of CO₂ for EOR operations, and infrastructure to support EOR operations. The top three ranked basins are the onshore Bowen-Surat, Cooper-Eromanga and offshore Gippsland Basins, which are all in relatively close proximity to the large east coast energy/oil markets. A significant factor that differentiates these three basins from the others considered in this study is their relatively good access to CO₂ and well-developed infrastructure. The next three most suitable basins are located offshore on the Northwest Shelf (Browse, Carnarvon, and Bonaparte Basins). While these three basins have mostly favourable oil properties and reservoir conditions, the sparse CO₂ sources and large distances involved lead to lower scores overall. The Canning and Amadeus Basins rank the lowest among the basins assessed, being relatively immature and remote hydrocarbon provinces, and lacking the required volumes of CO₂ or infrastructure to economically implement CO₂-EOR. In addition to ranking the basins for successful implementation of CO₂-EOR, we also provide some quantification of the potential recoverable oil in the various basins. These estimates used the oil and condensate reserve numbers that are available from national databases combined with application of internationally observed tertiary recovery factors. Additionally, we estimate the potential mass of CO₂ that would be required to produce these potential recoverable oil and condensate resources. In the large oil- and condensate-bearing basins, such as the Carnarvon and Gippsland Basins, some scenarios require over a billion tonnes of CO₂ to unlock the full residual resource, which points to CO₂ being the limiting factor for full-scale CO₂-EOR development. Even taking a conservative view of the available resources and potential extent of CO₂-EOR implementation, sourcing sufficient amounts of CO₂ for large-scale deployment of the technology presents a significant challenge. <b>Citation:</b> Tenthorey, E., Kalinowski, A., Wintle, E., Bagheri, M., Easton, L., Mathews, E., McKenna, J., Taggart, I. 2022. Screening Australia’s Basins for CO2-Enhanced Oil Recovery (December 6, 2022). <i>Proceedings of the 16th Greenhouse Gas Control Technologies Conference (GHGT-16) 23-24 Oct 2022</i>, Available at SSRN: <a href="https://ssrn.com/abstract=4294743">https://ssrn.com/abstract=4294743</a> or <a href="http://dx.doi.org/10.2139/ssrn.4294743">http://dx.doi.org/10.2139/ssrn.4294743</a>

Natural hydrogen is receiving increasing interest as a potential low-carbon fuel. There are various mechanisms for natural hydrogen generation but the reduction of water during oxidation of iron in minerals is recognised to be the major source of naturally generated H2. While the overall reaction is well known, the identity and nature of the key rate limiting steps is less understood. This study investigates the dominant reaction pathways through the use of kinetic modelling. The modelling results suggest there are a number of conditions required for effective H2 production from iron minerals. These include the presence of ultramafic minerals that are particularly high in Fe rather than Mg content, pH in the range of 8 to 10, solution temperatures in the 200 to 300oC range, and strongly reducing conditions. High reaction surface area is key and this could be achieved by the presence of finely deposited material and/or assemblages of high porosity or with mineral assemblages with surface sites that are accessible to water. Finally, conditions favouring the co-deposition of Ni together with FeO/Fe(OH)2-containing minerals such as brucite (and, possibly, magnetite) could enhance H2 generation

The ‘Australia’s Future Energy Resources’ (AFER) project is a four-year multidisciplinary investigation of the potential energy commodity resources in selected onshore sedimentary basins. The resource assessment component of the project incorporates a series of stacked sedimentary basins in the greater Pedirka-western Eromanga region in eastern central Australia. Using newly reprocessed seismic data and applying spatially enabled, exploration play-based mapping tools, a suite of energy commodity resources have been assessed for their relative prospectivity. One important aspects of this study has been the expansion of the hydrocarbon resource assessment work flow to include the evaluation of geological storage of carbon dioxide (GSC) opportunities. This form of resource assessment is likely to be applied as a template for future exploration and resource development, since the storage of greenhouse gases has become paramount in achieving the net-zero emissions target. It is anticipated that the AFER project will be able to highlight future exploration opportunities that match the requirement to place the Australian economy firmly on the path of decarbonisation.

<div>Carbon capture and storage (CCS) is gaining momentum globally. The Global CCS Institute notes in their Status of CCS 2023 report that there are 26 carbon capture and storage projects under construction and a further 325 projects in development, with a total capture capacity of 361 million tonnes per year (Mt/y) of carbon dioxide (CO2). Some CCS projects require the extraction of brackish or saline water (referred to here on in as brine) from the storage formation to manage increased pressure resulting from CO2 injection and/or to optimise subsurface storage space. It is important to consider the management of extracted brine as the CCS industry scales up due to implications for project design, cost and location as well as for the responsible management of the ‘waste’ or by-product brine. The use and disposal of reservoir brine has been investigated for CCS projects around the world, but not for Australian conditions. We have undertaken this review to explore how extracted brine could potentially be managed by CCS projects across Australia.&nbsp;</div>