Underground hydrogen storage (UHS) in halite caverns will become an essential technology to supplement energy supply networks. This study examines the feasibility of UHS in the offshore Polda Basin by integrating previous seismic interpretation, well data and regional geology information. The Mercury structure in the central – east Polda Basin has extensive halite accumulations (both vertically and laterally) and has been identified as an area with high UHS potential. The net halite thickness is more than 1000 m, while the total potential area is about 217 km². Well data from the Mercury 1 well show a low thermal gradient (1.7–2.1 °C/100m) and overburden pressure gradient of approximately 18 ppg, providing effective gas operation pressure for UHS. To illustrate the feasibility of UHS, a conceptual design of a halite cavern is provided for a depth range of 1650–2000 m. Caverns with diameters of 60 m and 100 m are estimated to have storage capacities of approximately 240 GWh and 665 GWh, respectively. Multiple halite caverns could be constructed within the extensive Mercury halite accumulation. Further investigation into the potential for salt accumulations in the onshore Polda Basin is recommended. <b>Citation: </b>Feitz A. J., Wang L., Rees S. & Carr L., 2022. Feasibility of underground hydrogen storage in a salt cavern in the offshore Polda Basin. In: Czarnota, K. (ed.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra, https://dx.doi.org/10.26186/146501

<div>Geoscience Australia’s Onshore Basin Inventories program provides a whole-of-basin inventory of geology, energy systems, exploration status and data coverage of onshore Australian basins. Volume 1 of the inventory covers the McArthur, South Nicholson, Georgina, Wiso, Amadeus, Warburton, Cooper and Galilee basins and Volume 2 expands this list to include the Officer, Perth and onshore Canning basins. These reports provide a single point of reference and create a standardised national inventory of onshore basins. In addition to summarising the current state of knowledge within each basin, the onshore basin inventory identifies critical science questions and key exploration uncertainties that may help inform future work program planning and aid in decision making for both government and industry organisations. Under Geoscience Australia’s Exploring for the Future (EFTF) program, six new onshore basin inventory reports will be delivered. </div><div>&nbsp;</div><div>These reports will be supported by selected value-add products that aim to address identified data gaps and evolve regional understanding of basin evolution and prospectivity. Petroleum system modelling is being undertaken in selected basins to highlight the hydrocarbon potential in underexplored provinces, and seismic reprocessing and regional geochemical studies are underway to increase the impact of existing datasets. The inventories are supported by the ongoing development of the nationwide source rock and fluids atlas, accessed through Geoscience Australia’s Exploring for the Future Data Discovery Portal, which continues to improve the veracity of petroleum system modelling in Australian onshore basins.</div><div>&nbsp;</div><div>In summarising avenues for further work, the Onshore Basin Inventories program has provided scientific and strategic direction for pre-competitive data acquisition under the EFTF work program. Here, we provide an overview of the current status of the Onshore Basin Inventories, with emphasis on its utility in shaping EFTF data acquisition and analysis, as well as new gap-filling data acquisition</div> This Abstract was submitted/presented at the 2023 Australasian Exploration Geoscience Conference (AEGC) 13-18 March (https://2023.aegc.com.au/)

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.

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.

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>

<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>

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.

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 Exploring for the Future program Showcase 2023 was held on 15-17 August 2023. Day 1 - 15th August talks included: Resourcing net zero – Dr Andrew Heap Our Geoscience Journey – Dr Karol Czarnota You can access the recording of the talks from YouTube here: <a href="https://youtu.be/uWMZBg4IK3g">2023 Showcase Day 1</a>

All commercially produced hydrogen worldwide is presently stored in salt caverns. In eastern Australia, the only known thick salt accumulations are found in the Boree Salt of the Adavale Basin in central Queensland. Although the number of wells penetrating the basin is limited, salt intervals up to 555 m thick have been encountered. The Boree Salt consists predominantly of halite and is considered to be suitable for hydrogen storage. Using well data and historical 2D seismic interpretations, we have developed a 3D model of the Adavale Basin, particularly focussing on the thicker sections of the Boree Salt. Most of the salt appears to be present at depths greater than 2000 m, but shallower sections are found in the main salt body adjacent to the Warrego Fault and to the south at the Dartmouth Dome. The preliminary 3D model developed for this study has identified three main salt bodies that may be suitable for salt cavern construction and hydrogen storage. These are the only known large salt bodies in eastern Australia and therefore represent potentially strategic assets for underground hydrogen storage. There are still many unknowns, with further work and data acquisition required to fully assess the suitability of these salt bodies for hydrogen storage. Recommendations for future work are provided. <b>Citation:</b> Paterson R., Feitz A. J., Wang L., Rees S. & Keetley J., 2022. From A preliminary 3D model of the Boree Salt in the Adavale Basin, Queensland. In: Czarnota, K. (ed.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra, https://dx.doi.org/10.26186/146935