<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>Geoscience Australia and CSIRO have collaborated, under the Exploring for the Future program, to investigate whether water-saturated residual oil zones (ROZs), sometimes associated with conventional Australian hydrocarbon plays, could provide a CO2 storage resource and enhance the storage capacity of depleted fields. This product is part of a larger project that includes, among others, a reservoir modelling component. </div><div>This report focuses on our petrophysical module of work that investigated the occurrence and character of ROZs in onshore Australian basins. Our findings demonstrate that ROZs occur in Australia’s hydrocarbon-rich regions, particularly in the Cooper-Eromanga Basin. ROZs with more than 10% residual oil saturation are uncommon, likely due to small original oil columns and lower residual saturations retained in sandstone reservoirs than in classic, carbonate-hosted North American ROZs. Extensive, reservoir-quality rock is found below the deepest occurring conventional oil in many of the fields in the Eromanga Basin, potentially offering significant CO2 storage capacity.&nbsp;</div><div>For more information about this project and to access the related studies and products, see: https://www.eftf.ga.gov.au/carbon-co2-storage-residual-oil-zones. </div><div><br></div>

<div>Geoscience Australia’s Exploring for the Future program provides precompetitive information 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 leads to a strong economy, resilient society and sustainable environment for the benefit of all Australians. This includes supporting Australia’s transition to net zero emissions, strong, sustainable resources and agriculture sectors, and economic opportunities and social benefits for Australia’s regional and remote communities. The Exploring for the Future (EFTF) program, which commenced in 2016, is an eight year, $225m investment by the Australian Government. </div><div><br></div><div>As part of the EFTF Program, Geoscience has completed a 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. The AFER Project has adapted the conventional hydrocarbon play-based exploration workflow, developed by the petroleum industry over several decades, to develop a similar approach for assessing unconventional hydrocarbon resource potential and CO2 geological storage prospectivity. Play-based exploration is a method of building and leveraging an understanding of a basin and its sediment-hosted resources by systematically evaluating a series of play intervals using the best available geological data and models. Each play interval represents a regionally significant reservoir/aquifer for one or more resources (e.g. hydrocarbons, groundwater, CO2 storage intervals) often with an associated seal/aquitard. Various ‘risk elements’ that are essential for a resource to exist can be mapped and qualified with a probability of geological success. These risk elements are then spatially integrated (stacked) to generate common risk segment (CRS) or ‘heat’ maps for each play interval that indicate areas of relatively high prospectivity versus relatively low prospectivity. Geological risk elements are evaluated using post-drill analysis of well control points, and geological maps generated from basin studies.</div><div><br></div><div>Common risk segment mapping, supported by post-drill analysis, has been undertaken by the AFER Project using the GIS-Pax Player Software, and assigned a geological probability of success (POS) using a ‘split risking’ system that involves assessing: </div><div>·&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Pg play, which is the POS that the risk element is effective somewhere within the map segment; </div><div>·&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Pg repeatability, which is the POS of future repeated effective discoveries for the risk element within the map segment (i.e. the inherent variability or heterogeneity of the risk element); and the </div><div>·&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Pg overall (Pg play x Pg repeatability). </div><div><br></div><div>This data package provides a spatial data set (CRS maps and post-drill analysis) capturing the AFER project’s assessment of hydrocarbon resources (conventional hydrocarbons, coal seam gas, and shale hydrocarbons) and the CO2 geological storage potential of the Pedirka and western Eromanga basins. The data package includes the following data sets:</div><div>1.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Common risk segment maps for conventional hydrocarbons, unconventional hydrocarbons and CO2 geological storage resources provided in ESRI© ArcGIS file geodatabase format (gdb).</div><div>2.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Common risk segment maps for conventional hydrocarbons, unconventional hydrocarbons and CO2 geological storage resources provided in ESRI© shape format (shp).</div><div>3.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Post-drill analysis data provided in ESRI© shape format (shp).</div><div>4.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Metadata forms documenting key information (abstract, data sources, lineage for related groups of map layers, keywords) for each group of related CRS maps and for the post-drill analysis results. </div><div><br></div><div>The product authors wish to acknowledge Tehani Palu (Geoscience Australia) for her internal peer review of the digital data package, Darren Ferdinando (Basin Science Pty Ltd) for his review of the conventional hydrocarbon common risk segment mapping, and Catherine Flowers (Geoscience Australia) for her technical support in developing the GIS products.</div><div><br></div><div><br></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>

<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>This data package provides depth and isochore maps generated in support of the energy resource assessments under the Australia’s Future Energy Resources (AFER) project. Explanatory notes are also included.</div><div><br></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.</div><div><br></div><div>The depth and isochore maps are products of depth conversion and spatial mapping seismic interpretations by Szczepaniak et al. (2023) and Bradshaw et al. (2023) which interpreted 15 regional surfaces. These surfaces represent the top of play intervals being assessed for their energy resource potential (Figure 1). These seismic datasets were completed by play interval well tops by Bradshaw et al. (in prep), gross depositional environment maps, zero edge maps by Bradshaw et al. (in prep), geological outcrop data as well as additional borehole data from Geoscience Australia’s stratigraphic units database.</div><div><br></div><div>Depth and isochore mapping were undertaken in two to interactive phases; </div><div><br></div><div>1.&nbsp;&nbsp;&nbsp;&nbsp;A Model Framework Construction Phase – In this initial phase, the seismic interpretation was depth converted and then gridded with other regional datasets. </div><div><br></div><div>2.&nbsp;&nbsp;&nbsp;&nbsp;A Model Refinement and QC Phase – This phase focused on refining the model and ensuring quality control. Isochores were generated from the depth maps created in the previous phase. Smoothing and trend modelling techniques were then applied to the isochore to provide additional geological control data in areas with limited information and to remove erroneous gridding artefacts.&nbsp;</div><div><br></div><div>The final depth maps were derived from isochores, constructing surfaces both upward and downward from the CU10_Cadna-owie surface, identified as the most data-constrained surface within the project area. This process, utilizing isochores for depth map generation, honours all the available well and zero edge data while also conforming to the original seismic interpretation.</div><div><br></div><div>This data package includes the following datasets: </div><div><br></div><div>1)&nbsp;&nbsp;&nbsp;Depth maps, grids and point datasets measured in meters below Australian Height Datum (AHD, for 15 regional surfaces (Appendix A). </div><div>2)&nbsp;&nbsp;&nbsp;Isochore maps, grids and point datasets measured in meters, representing 14 surfaces/play internals (Appendix B).</div><div>&nbsp;</div><div>These depth and isochore maps are being used to support the AFER Project’s play-based energy resource assessments in the Pedirka and western Eromanga basins, and will help to support future updates of 3D geological and hydrogeological models for the Great Artesian Basin by Geoscience Australia.</div><div><br></div>

<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>

<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>

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 Pedirka, Simpson and western Eromanga basins in central Australia have undergone a chequered exploration history which has seen a total of only 42 wells drilled across a study area of ~210,000km2. Exploration initially focused on conventional hydrocarbons from the 1950s-1980s, before shifting towards coal seam gas (CSG) opportunities in the mid-2000s. Active petroleum systems have been proven in the region by a non-commercial oil discovery at Poolowanna 1 in 1977, and by several wells that showed evidence of residual oil columns. CSG exploration wells have confirmed the presence of thick, marginally mature coal intervals on the flanks of the basins, but are yet to evaluate the deeper troughs.</div><div>Geoscience Australia, the Northern Territory Geological Survey and the South Australian Department for Energy and Mining have been collaborating on the Australia’s Future Energy Resources project under the Australian government funded Exploring for the Future Program to undertake an assessment of the resource potential for conventional and unconventional hydrocarbons, and the geological carbon and storage (GCS) potential of the greater Pedirka region. </div><div>The project applied a play-based exploration approach to qualitatively assess the resource potential of the region. The Carboniferous to Cretaceous stratigraphic interval was divided into 14 plays which were evaluated for the presence of sediment-hosted energy resources through post-drill analysis, gross depositional environment mapping and common risk segment mapping. The analysis identified energy resources and GCS potential across multiple plays and locations within the study area. These results demonstrate, that while the region is underexplored, it should not be overlooked by future exploration activities.</div> Published in The APPEA Journal 2023. <b>Citation:</b> Iwanec Jeremy, Strong Paul, Bernecker Tom (2023) Underexplored but not forgotten: assessing the energy resources potential of the greater Pedirka Basin region through play-based mapping. <i>The APPEA Journal</i><b> 63</b>, S251-S256. https://doi.org/10.1071/AJ22150