Shale brittleness within the Paleoproterozoic Isa Superbasin succession in the South Nicholson region, Northern Australia

The South Nicholson region, which includes the Paleoproterozoic Isa Superbasin, Mesoproterozoic Group and overlying younger sediments, is sparsely explored has recently come into increased focus as a result of Australian Government’s Exploring for Future program. Previous exploration identified potential shale gas plays within River Lawn supersequences Superbasin in northwest Queensland’s northern Hill Platform region. Understanding mineralogy important characterising reservoirs, mechanical properties such brittleness are influenced by mineral composition. Mineralogy can, therefore, be utilised proxy that crucial to minimising risks associated with exploring developing reservoirs. This study utilises three different methods calculating brittleness: X-ray diffraction (XRD) mineralogy, fluorescence (XRF) major-element geochemistry derived elastic properties. Results indicate highly variable analysed samples, demonstrating heterogeneity throughout studied supersequences. Brittleness calculated from XRD analysis ranges ductile brittle, zones brittle shales present all Increasing quartz decreasing clay content dominant control on samples. Correlation between XRF demonstrated moderate poor, observed significantly higher than mineralogy. Conversely, agrees closely brittleness. As provides estimates excessively high minimal overlap other two datasets, use these data calculate region not recommended. Analysis indices this study, combination total organic carbon drawn regional geochemical identifies target intervals River, Term Data presented correlated well sections highlight interest supersequences, being those depths where high-organic-content, rocks identified. meet criterion primarily constrained already-known Recent Geoscience Australia imply lateral extent plays, likely extending Platform, underneath Basin Carrara Sub-basin. KEY POINTSThis values properties.Calculated should considered their utility screening tools rather accurate representations brittleness.Results supersequences.Analysis