<div>This data package provides petrophysical interpretations by Geoscience Australian and the South Australia Department for Energy and Mining (SADEM) for 23 wells generated in support of the energy resource assessments under the Australia’s Future Energy Resources (AFER) project in the Pedirka and western Eromanga basins. Interpreted petrophysical data in this data package include [BB1]&nbsp;[MB2]&nbsp;volume of clay/shale, porosity (total and effective), relative permeability, formation water salinity (NaCl equivalent), and apparent resistivity of water.</div><div>&nbsp;</div><div>The AFER project 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, Geoscience Australia is 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.This new data package consists of composite logs and supporting data which includes interpreted volume of clay/ shale, porosity, permeability and salinity.</div><div>&nbsp;</div><div>The data package includes the following datasets: </div><div>1)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Composite logs (PDF)</div><div>2)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Well logs (ASCII LAS)</div><div>3)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Well header information (Microsoft Excel™)[BB3]&nbsp;[MB4]&nbsp;</div><div>&nbsp;</div><div>These petrophysical interpretations are being used to support the AFER Project’s play-based energy resource assessments in the Pedirka and western Eromanga basins by building 3D geological models that include derived rock property maps.

<div>As part of the Exploring For The Future (EFTF) program, the Australia’s Future Energy Resources (AFER) project has investigated the potential of energy resource commodities in the Pedirka/western Eromanga basins region targeting conventional and unconventional hydrocarbons as well as evaluating the suitability of sedimentary sections to store carbon dioxide.</div><div>The interpretation of new biostratigraphic and reprocessed seismic data provided new insights into the regional geology of this previously explored region. The Permian, Triassic and Jurassic depositional history of the study area is largely recorded by extensive fluvial-lacustrine sediments, including changes from braided to meandering river systems and sustained periods of flood-plain environments in which thick sequences of coal-bearing strata developed. During the Cretaceous, expanding shallow marine environments were established in the western part of the Pedirka/western Eromanga region.</div><div>Age-control obtained from palynological analysis and the mapping of key seismic horizons yielded an improved understanding of the extent and character of unconformities which define breaks and changes in depositional processes. Results from new regional stratigraphic correlations initiated a comprehensive review of previously established basin definitions in the greater Pedirka/western Eromanga area. </div><div>While confirming the stacked nature of these basins which hold sedimentary records from the early Paleozoic to the Late Cretaceous, changes to stratigraphic basin boundaries have been applied to more correctly reflect the impact of unconformity related depositional breaks. As a result, the Lower and Middle Triassic Walkandi Formation is now assigned to the upper section of the Pedirka Basin, while the Upper Triassic Peera Peera Formation represents commencement of deposition in the western Eromanga Basin, thereby abandoning the recognition of the Simpson Basin as a separate Triassic depocenter.&nbsp;</div><div><br></div><div><br></div>

The document summarises new seismic interpretation metadata for two key horizons from Base Jurassic to mid-Cretaceous strata across the western and central Eromanga Basin, and the underlying Top pre-Permian unconformity. New seismic interpretations were completed during a collaborative study between the National Groundwater Systems (NGS) and Australian Future Energy Resources (AFER) projects. The NGS and AFER projects are part of Exploring for the Future (EFTF)—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. The seismic interpretations build on previous work undertaken as part of the ‘Assessing the Status of Groundwater in the Great Artesian Basin’ (GAB) Project, commissioned by the Australian Government through the National Water Infrastructure Fund – Expansion (Norton & Rollet, 2022; Vizy & Rollet, 2022; Rollet et al., 2022; Rollet et al., in press.), the NGS Project (Norton & Rollet, 2023; Rollet et al., 2023; Vizy & Rollet, 2023) and the AFER Project (Bradshaw et al., 2022 and in press, Bernecker et al., 2022, Iwanec et al., 2023; Iwanec et al., in press). The recent iteration of revisions to the GAB geological and hydrogeological surfaces (Vizy & Rollet, 2022) provides a framework to interpret various data sets consistently (e.g., boreholes, airborne electromagnetic, seismic data) and in a 3D domain, to improve our understanding of the aquifer geometry, and the lateral variation and connectivity in hydrostratigraphic units across the GAB (Rollet et al., 2022). Vizy and Rollet (2022) highlighted some areas with low confidence in the interpretation of the GAB where further data acquisition or interpretation may reduce uncertainty in the mapping. One of these areas was in the western and central Eromanga Basin. New seismic interpretations are being used in the western Eromanga, Pedirka and Simpson basins to produce time structure and isochore maps in support of play-based energy resource assessment under the AFER Project, as well as to update the geometry of key aquifers and aquitards and the GAB 3D model for future groundwater management under the NGS Project. These new seismic interpretations fill in some data and knowledge gaps necessary to update the geometry and depth of key geological and hydrogeological surfaces defined in a chronostratigraphic framework (Hannaford et al., 2022; Bradshaw et al., 2022 and in press; Hannaford & Rollet, 2023). The seismic interpretations are based on a compilation of newly reprocessed seismic data (Geoscience Australia, 2022), as part of the EFTF program, and legacy seismic surveys from various vintages brought together in a common project with matching parameters (tying, balancing, datum correcting, etc.). This dataset has contributed to a consolidated national data coverage to further delineate groundwater and energy systems, in common data standards and to be used further in integrated workflows of mineral, energy and groundwater assessment. The datasets associated with the product provides value added seismic interpretation in the form of seismic horizon point data for two horizons that will be used to improve correlation to existing studies in the region. The product also provides users with an efficient means to rapidly access a list of core data used from numerous sources in a consistent and cleaned format, all in a single package. The following datasets are provided with this product: 1) Seismic interpretation in a digital format (Appendix A), in two-way-time, on key horizons with publically accessible information, including seismic interpretation on newly reprocessed data: Top Cadna-owie; Base Jurassic; Top pre-Permian; 2) List of surveys compiled and standardised for a consistent interpretation across the study area (Appendix B). 3) Isochore points between Top Cadna-owie and Base Jurassic (CC10-LU00) surfaces (Appendix C). 4) Geographical layer for the seismic lines compiled across Queensland, South Australia and the Northern Territory (Appendix D). These new interpretations will be used to refine the GAB geological and hydrogeological surfaces in this region and to support play-based energy resource assessments in the western Eromanga, Pedirka and Simpson basins.

<div>The “Australia’s Future Energy Resources” (AFER) project, funded under the Government’s “Exploring for the Future” (EFTF) program has been completed. The project’s four modules have evaluated a mixture of energy resource commodities, including natural gas, hydrogen, subsurface storage opportunities for carbon dioxide and hydrogen. They are complimented by several targeted basin inventories which outline the current geological knowledge of energy resources in underexplored, data-poor regions. Several publicly available data sets have been generated and published under the AFER project, including 3,750&nbsp;line-km of reprocessed 2D seismic data, acquired in the Pedirka and western Eromanga basins, of which key lines have been interpreted and integrated with geological and petrophysical well log data. Relative prospectivity maps have been produced for five energy resource commodities from 14&nbsp;play intervals to show the qualitative variability in prospectivity of these resources, including quantitative resource assessments where warranted. Results from the AFER project have helped to identify and geologically characterise the required energy resource commodities to accelerate Australia’s path to net zero emissions.</div> Presented at the Australian Energy Producers (AEP) Conference & Exhibition (https://energyproducersconference.au/conference/)

Geoscience Australia commissioned reprocessing of selected legacy 2D seismic data in the Pedirka-Simpson Basin in South Australia-Northern Territory as part of the Exploring for the Future (EFTF) program. 34 Legacy 2D seismic lines from the Pedirka Basin were reprocessed between May 2021 and January 2022 (phase 1). An additional 54 legacy 2D seismic lines (34 lines from Pedirka Basin, South Australia and 20 lines from Simpson Basin, Northern Territory) were reprocessed between November 2021 and June 2022 (phase 2). Geofizyka Toruń S.A. based in Poland carried out the data processing and Geoscience Australia with the help of an external contractor undertook the quality control of the data processing. The seismic data release package contains reprocessed seismic data acquired between 1974 and 2008. In total, the package contains approximately 3,806.9 km of industry 2D reflection seismic data. The seismic surveys include the Beal Hill, 1974; Pilan Hill, 1976; Koomarinna, 1980; Christmas Creek, 1982; Hogarth, 1984; Morphett, 1984; Colson 2D, 1985; Etingimbra, 1985; Fletcher, 1986; Anacoora, 1987; Mitchell, 1987; Bejah, 1987; Simpson Desert, 1979, 1984, 1986, 1987; Forrest, 1988; Eringa Trough, 1994; Amadeus-Pedirka, 2008 and covers areas within the Amadeus Basin, Simpson Basin, Pedirka Basin, Warburton Basin and Cooper Basin in South Australia and Northern Territory. The objective of the seismic reprocessing was to produce a processed 2D land seismic reflection dataset using the latest processing techniques to improve resolution and data quality over legacy processing. In particular, the purpose of the reprocessing was to image the structure and stratigraphic architecture of the Neoproterozoic to Late Palaeozoic Amadeus Basin, Triassic Simpson Basin, Cambrian–Devonian Warburton Basin, Permian–Triassic Pedirka Basin and Cooper Basin. All vintages were processed to DMO stack, Pre-stack Time Migration and Post-Stack Time Migration. <b>Data is available on request from clientservices@ga.gov.au - Quote eCat# 146309</b>

<div>As part of the EFTF Program, Geoscience has completed a 4-year multi-disciplinary study to investigate the energy resource potential of selected onshore basins within central Australia under the Australia’s Future Energy Resources (AFER) Project. A key component of the AFER Project has been a qualitative and quantitative play-based assessment of hydrocarbon resources and geological storage of CO2 (GSC) potential within the Pedirka and western Eromanga basins (Bradshaw et al., 2024a). This study has provided a regional interpretive data set which includes regional seismic and well log interpretations (Bradshaw et al.&nbsp;2024b, 2024c); depth-structure and isochore maps for 14 play intervals (Iwanec et al., 2024); gross-depositional environment maps for 14 play intervals (Bradshaw et al., 2024c); and petrophysical analysis of wireline log data from 23 wells (Spicer et al., 2024). This report provides a high-level summary of the hydrogeology of Pedirka and western Eromanga basins as background information for the other assessments and some findings from the 3D models that may inform future understanding of the hydrogeology of these basins. </div><div><br></div><div>The assessment area extends over ~210,000 km2 across the Northern Territory, South Australia and Queensland (Figure 1). Much of the assessment area underlies national parks in South Australia and Queensland. No petroleum exploration access is allowed in the Munga Thirri Simpson Desert Conservation Park or the Witjira National Park (Dalhousie Springs area) in South Australia or Munga Thirri National Park in Queensland (Figure 1).</div><div><br></div><div>The AFER assessment area is situated within the Kati Thanda-Lake Eyre surface water catchment. The catchment’s arid climate and ephemeral river flow regime (Evans et al., 2024) makes groundwater a critical source of water for the environment, industry and communities, especially during dry periods. Groundwater dependent features in the region include water supplies for communities, industry and pastoral stations, as well as springs and other groundwater dependent ecosystems. Groundwater resources are managed by state and territory jurisdictions (see: NT Government, 2013; Queensland Government, 2017, SA Government, 2021). Across the three jurisdictions, the most important groundwater resources are those of the western Eromanga Basin (a part of Great Artesian Basin or GAB). In collaboration with state jurisdictions the Commonwealth provides a cross-jurisdictional policy framework for the GAB as well as the Lake Eyre surface water basin (DCCEEW, 2024). Key management goals include maintaining artesian pressures, water quality and viability of GAB dependent ecosystems, including springs.&nbsp;</div><div><br></div><div><br></div><div><br></div>

<div>Palynology preparations from 62 samples from several key wells in the Northern Territory section of the Pedirka Basin were examined for Geoscience Australia. The sampling was done by the Geological Survey of NT (see table 1 for sample listing). All resulting slides and remaining residue have been submitted to government. The samples were analysed quantitatively with the first 200 specimens in each sample counted and subsequent species simply recorded as present. In this summary report, the results are provided in tabulated form only. Details of the palynomorph assemblages are recorded on StrataBugs distribution charts, with each taxon expressed as a percentage of the entire assemblage (Appendix B). From this information, assignments are made to the palynostratigraphic scheme of Price (1997), as shown in Figures 1 and 2 and summarised in Appendix A.</div><div>Wells included are: Blamore-1, CBM 93-002, CBM 93-004, CBM 107-001, CBM 107-002, Hale River-1, Simpson-1, Thomas-1. </div><div>Also see accompanying report by Hannaford and Mantle, 2022: Palynological analysis of infill samples for selected wells in the South Australian section of the Pedirka Basin. eCat 147227</div>

<div>Identifying potential basin areas for future Geological Storage of CO2 (GSC) exploration is essential to support Australia’s transition to a net zero emissions energy future. Geoscience Australia’s AFER Project has completed a play-based assessment of the GSC potential in the Pedirka and western Eromanga basins using regionally extensive aquifers containing saline to slightly brackish formation waters. There are currently no significant anthropogenic CO2 sources or associated storage projects in the assessment area. Understanding the area’s GSC potential does, however, assist in providing options for addressing CCS requirements in the central Australian region, including any future opportunities to remove anthropogenic CO2 using Direct Air Capture and Storage technologies. </div><div><br></div><div>The AFER Project’s assessments are underpinned by new geological insights into the basins and a supporting upscaled 3D geological model. A play-based common risk segment mapping approach has been applied to five potential storage (play) intervals to delineate basin areas with relatively high prospectivity based on four geological risk elements: injectivity, storage effectiveness, containment, and structural complexity. Results from this qualitative component of the assessment highlights a potentially prospective area for future GSC exploration extending across the Northern Territory, South Australia and Queensland. The most prospective interval on a geological probability of success basis is the Namur-Murta play interval. </div><div><br></div><div>Results from the qualitative GSC assessment have been used as a screening tool to delineate areas for quantitative modelling of the range of Estimated Ultimate Storage (EUS) volumes using deterministic and probabilistic methodologies. EUS volumes have been estimated in two model areas representing geological end members in storage interval heterogeneity and potentially prospective areas outside of the extents of current national parks. The EUS potential is high (10’s of gigatonnes) in the two model areas using both deterministic and probabilistic workflows, as expected for a regional assessment using very large pore volumes. Applying a geological probability of success based on injectivity and structural and stratigraphic containment reduces the volumes in the two model areas to a risked best estimate EUS of 13 Gt in the eastern area and a risked best estimate EUS of 2 Gt in the western area. Results from the quantitative assessment suggest that both model areas can support multiple industrial-scale CCS projects injecting 50 Mt CO2 over a 20-year period. However, heterogeneous reservoirs that extend over the eastern assessment area are likely to have greater storage efficiencies and an associated smaller project footprint of 29 km2 using three CO2 injection wells. Relatively homogenous reservoirs elsewhere in the assessment area have lower storage efficiencies due to a lack of intraformational seals within the Algebuckina Sandstone and have an associated larger project area of 49 km2 using three CO2 injection wells. Pressure management requirements are likely to be minimal in both model areas due to the thick and open nature of reservoirs. However, water production rates of up to 16,500 m3/day may be required where local lateral barriers to pressure dissipation occur. &nbsp;&nbsp;&nbsp;</div><div><br></div><div>Results from the AFER Project's GSC assessment demonstrate the value of applying a play-based exploration workflow for a regional-scale energy resource assessment. Estimating the geological probability of success to the presence and repeatability of four mappable risk elements associated with GSC resources allows both relative prospectivity maps and risked EUS volumes to be generated. Prospectivity maps and EUS volumes can in turn be readily updated as new geological data are collected to infill data and knowledge gaps. Geoscience Australia is building a national inventory of GSC resources using this play-based exploration approach, with qualitative assessments now completed under the EFTF and TEGI programs in seven basin areas from central and eastern Australia.&nbsp;</div><div><br></div>

<div>Palynology preparations from 50 samples from several key wells in the South Australian section of the Pedirka Basin were examined for Geoscience Australia. The sampling was done by Carey Hannaford under inspection number 5358 (see table 1 for sample listing). All resulting slides and remaining residue have been submitted to government. The samples were analysed quantitatively with the first 200 specimens in each sample counted and subsequent species simply recorded as present. In this summary report, the results are provided in tabulated form only. Details of the palynomorph assemblages are recorded on StrataBugs distribution charts, with each taxon expressed as a percentage of the entire assemblage (Appendix B). From this information, assignments are made to the palynostratigraphic scheme of Price (1997), as shown in Figures 1 and 2 and summarised in Appendix A.</div><div>Wells included are: Erabena-1, Macumba-1, Mokari-1, Oolarinna-1, Pandieburra-1, Poolowanna-1, Poolowanna-2, Walkandi-1. </div><div>Also see accompanying report by Hannaford and Mantle, 2022: Palynological analysis of infill samples for selected wells in the Northern Territory section of the Pedirka Basin.</div>

<div>Understanding the hydrocarbon potential of Australia’s sedimentary basins is critical to ensuring the nation’s future energy security. The Pedirka and western Eromanga basins have proven petroleum potential with a sub-commercial oil discovery at Poolowanna 1 in the Poolowanna Trough and several wells drilled over the Colson Shelf and Madigan Trough showing evidence for residual oil zones. However, these basins remain relatively underexplored with only 42 petroleum wells drilled and relatively sparse 2D seismic data coverage. Geoscience Australia’s AFER Project has undertaken a qualitative and quantitative play-based assessment of the Pedirka and western Eromanga basins to enable a better understanding of their undiscovered hydrocarbon resources.</div><div><br></div><div>The AFER Project’s assessments are underpinned by new geological insights into the western Eromanga Basin and a supporting upscaled 3D geological model. A play-based common risk segment (CRS) mapping approach has been applied to eleven play intervals to delineate basin areas with relatively high prospectivity based on five geological risk elements: reservoir presence, reservoir effectiveness, top seal, trap presence, and hydrocarbon charge. Results from this qualitative component of the assessment indicate that the highest potential for future hydrocarbon discoveries is likely to be conventional oil resources across the Poolowanna Trough, Colson Shelf and Madigan Trough. The most prospective exploration targets are the Namur-Murta, Poolowanna and Peera Peera play intervals on a geological probability of success basis. The Peera Peera and Poolowanna play intervals have proven hydrocarbon charge from the Poolowanna 1 oil discovery but show poor reservoir quality (porosity <10%) in wells drilled across the Poolowanna Trough. These play intervals likely represent tight conventional oil exploration targets across their main play fairways in the Poolowanna Trough. The Namur-Murta interval has high reservoir qualities across all potentially prospective areas but has lower certainty regarding hydrocarbon charge with the most significant exploration result to date being a residual oil zone in the Madigan Trough. Moderate to high prospectivity for conventional oil is interpreted to occur in the Adori-Westbourne, Birkhead and Hutton play intervals over the eastern flanks of the Poolowanna Trough and western flanks of the Birdsville Track Ridge. The Walkandi, Upper Purni, Lower Purni and Crown Point play intervals are assessed as having moderate prospectivity for conventional oil over the Eringa Trough, Madigan Trough and Colson Shelf. </div><div><br></div><div>A quantitative assessment of the ‘Yet to Find’ hydrocarbon volumes has been undertaken to provide a play-level indication of the possible undiscovered conventional oil volumes. The risked volumes include a ‘Base Case’ that reflects the current exploration understanding of the basins, and a ‘High Case’ that reflects the potential impact of a new working petroleum system being discovered in the basins. The mean risked recoverable oil volume for the Base Case scenario total 22.2 MMbbl for the four plays evaluated (Namur-Murta, Poolowanna, Peera Peera and Lower Purni). About 70% of the risked mean volumes occur in the Poolowanna and Namur-Murta play intervals. Results from the High Case model highlight the significantly greater YTF potential across the basins if the geological requirement for a new working petroleum system eventuates from further exploration, with a total mean risked volume of 234.8 MMbbl for the three play intervals evaluated (Namur-Murta, Poolowanna and Lower Purni). Risked volumes are relatively evenly distributed across the three play intervals. &nbsp;&nbsp;</div><div><br></div><div>Unconventional hydrocarbons are evaluated as being less prospective than conventional hydrocarbons in the western Eromanga basin. Shale oil plays have not previously been explored but may be present within organic-rich shales from the Poolowanna and Peera Peera play intervals. These shale oil plays are evaluated as being moderately prospectivity due to their thin and heterogeneous character. Coal seam gas (CSG) wells drilled into the Upper Purni and Lower Purni play intervals have to date only demonstrated the presence of gas-undersaturated coal seams over the Andado Shelf. However, CSG is the most likely hydrocarbon resource type to produce hydrocarbons from the Pedirka Basin if future exploration can identify sweet spots where different geological conditions occur that are conducive to preserving high gas saturations.&nbsp;</div><div><br></div>