Australia’s Future Energy Resources (AFER) Project: Regional hydrogeology of the Pedirka and western Eromanga basins

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. 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.

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).

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.