Geoscience Australia is undertaking a series of basin-scale assessments to identify the ‘yet-to-find’ resource potential for hydrocarbons, as well as for groundwater resources and carbon capture and storage (CCS) opportunities in central Australia under the Exploring for the Future (EFTF) Program. A play-based exploration approach is being used to systematically evaluate the key risk elements for each resource type through the analysis of drilling results and spatial data to map ‘sweet spots’ for exploration. These assessments aim to reduce the risks and uncertainties for explorers by providing spatially enabled assessments of energy resources and CCS potential. The work will also improve the understanding of existing groundwater resources which may be impacted by future energy resource developments or provide feedstock for future green hydrogen projects. A key requirement for undertaking such play-based resource assessments is to apply a common regional chronostratigraphic framework across all the resource types that link different geological unit nomenclatures through defining the assessed reservoir and seal intervals and their associated sequence stratigraphic surfaces (sequence boundaries, transgressive surfaces and maximum flooding surfaces). A Mesozoic chronostratigraphic framework has been developed for the Eromanga Basin, which defines nine regional play intervals that host the known hydrocarbon and groundwater resources, or represent potential CCS targets. The Mesozoic play framework is now being applied to undertake play-based low-carbon energy resource assessments in the western Eromanga Basin, with initial work focussing on the interpretation and correlation of the nine play intervals in wells for post-drill analysis.

The Pedirka, Simpson and western Eromanga basins in central Australia have had a chequered exploration history which has seen only 42 wells drilled across a study area of ~210 000 km2. 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 programs have confirmed the presence of thick, marginally mature coal intervals on the flanks of the basins, but are yet to evaluate the CSG potential of the deeper troughs. 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 to undertake an assessment of the resource potential for conventional and unconventional hydrocarbons, and the geological storage of CO2 (GSC) potential of the greater Pedirka region. The project has 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 GSC 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.

The upper Permian to lower Triassic sedimentary succession in the southern Bonaparte Basin represents an extensive marginal marine depositional system that hosts several gas accumulations, including the Blacktip gas field that has been in production since 2009. Development of additional identified gas resources has been hampered by reservoir heterogeneity, as highlighted by preliminary results from a post drill analysis of wells in the study area that identify reservoir effectiveness as a key exploration risk. The sedimentary succession that extends across the Permian–Triassic stratigraphic boundary was deposited during a prolonged marine transgression and shows a transition in lithofacies from the carbonate-dominated Dombey Formation to the siliciclastic-dominated Tern and Penguin formations. Recent improvements in chronostratigraphic calibration of Australian biostratigraphic schemes, spanning the late Permian and early Triassic, inform our review of available palynological data, and re-interpretation and infill sampling of well data. The results provide a better-resolved, consistent and up-to-date stratigraphic scheme, allowing an improved understanding of the timing, duration and distribution of depositional environments of the upper Permian to lower Triassic sediments across the Petrel Sub-basin and Londonderry High.