Underexplored but not forgotten: assessing the energy resources potential of the greater Pedirka Basin region through play-based mapping

Abstract

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.

Australia’s Future Energy Resources project: the untapped potential of onshore low carbon energy resources

“…Post-drill analyses of 42 wells (Iwanec et al 2023) were carried out and coupled with the mapping of grossdepositional environments, petrophysical analysis of wireline log data to constrain net shale and sand thickness, effective porosities and relative permeabilities, to construct common risk segment (CRS) maps for each of the four energy resource commodities within the 14 play intervals. These CRS maps form the foundation of the project's qualitative energy resource commodity assessments.…”