<div>The Roebuck Basin on Australia’s offshore north-western margin is the focus of regional energy exploration activity. Drilling in the Roebuck Basin resulted in oil and gas discoveries at Phoenix South&nbsp;1 (2014), Roc&nbsp;1 (2015–2016) and Dorado&nbsp;1 (2018) in the Bedout Sub-basin (Figure 1‑2) and demonstrated the presence of a petroleum system in Lower Triassic strata. These discoveries have been evaluated for development and production with infill drilling at Roc&nbsp;2 (2016), Phoenix South&nbsp;2 (2016), Phoenix South&nbsp;3 (2018), Dorado&nbsp;2 (2019), and Dorado&nbsp;3 (2019). Recent drilling by Santos (2022) has resulted in the discovery of oil at Pavo&nbsp;1 (2022) and hydrocarbon shows at Apus&nbsp;1 (2022).</div><div><br></div><div>To complement this industry work, Geoscience Australia’s Offshore Energy Systems program produces pre-competitive information to assist with the evaluation of the energy and resource potential of the central North West Shelf, including both hydrogen and helium resources, and to attract exploration investment to Australia. As part of this program, determination of the molecular and noble gas isotopic composition of natural gases from selected petroleum wells in the Roebuck Basin were undertaken by Smart Gas Sciences, under contract to Geoscience Australia, with results from these analyses being released in this report. This report provides additional gas data to determine the sources of natural gases in the Roebuck Basin and build on previously established gas-gas correlations. Noble gas isotopic data can be used in conjunction with carbon and hydrogen isotopic data to determine the origin of both inorganic and organic (hydrocarbon) gases. This information can be used in future geological programs to determine the source and distribution of hydrogen and helium in natural gases and support acreage releases by the Australian Government.</div><div><br></div>

<div>A regional hydrocarbon prospectivity assessment has been undertaken of the offshore Otway Basin by the Offshore Energy Systems Section. This program was designed to produce pre-competitive information to assist with the evaluation of the hydrocarbon resource potential of the offshore Otway Basin and attract exploration investment to Australia. The inboard part of the basin is an established hydrocarbon province with onshore and shallow-water offshore discoveries, whereas the outboard deep-water region, where water depths range from 500 to 6300&nbsp;m, is comparatively underexplored and considered a frontier area.</div><div><br></div><div>As part of this program, molecular and noble gas isotopic analyses were undertaken by Smart Gas Sciences, under contract to Geoscience Australia on available gas samples from the Waarre Formation in the Shipwreck Trough in the offshore eastern Otway Basin, with data from these analyses being released in this report. This report provides additional compositional information for gases in the Waarre Formation reservoirs and builds on previously established gas-gas correlations and gas-oil correlations. Noble gas isotopic data can be used in conjunction with carbon and hydrogen isotopic data to determine the origin of both inorganic and organic (hydrocarbon) gases. This information can be used in future geological programs to determine the source and distribution of hydrogen and helium in natural gases and support acreage releases by the Australian Government.</div><div><br></div><div><br></div>

<div>The pyrolysis-reflectance tie database table contains publicly available results from Geoscience Australia's organic geochemistry (ORGCHEM) schema and supporting oracle databases, which combine key properties related to thermal maturity. These data are typically used as input parameters in basin analysis and petroleum systems modelling to assist with the discovery and evaluation of sediment-hosted energy resources. The programmed pyrolysis analyses and the maceral reflectance analyses undertaken using reflected light microscopy are conducted on rock samples, either as cores, cuttings or rock chips, taken from boreholes and field sites in Australian sedimentary basins. The full datasets are available in the pyrolysis, vitrinite reflectance, maceral reflectance and organoclast maturity web services. These analyses are performed by various laboratories in service and exploration companies, Australian government institutions and universities using a range of instruments.</div><div><br></div><div>These data are collated from destructive analysis reports (DARs), well completion reports (WCRs), and literature. The data are delivered in the Combined Pyrolysis and Vitrinite Reflectance web services on the Geoscience Australia Data Discovery Portal at https://portal.ga.gov.au which will be periodically updated.</div>

<div>The bulk source rock database table contains publicly available results from Geoscience Australia's organic geochemistry (ORGCHEM) schema and supporting oracle databases for the bulk properties of sedimentary rocks that contain organic matter and fluid inclusions taken from boreholes and field sites. The analyses are performed by various laboratories in service and exploration companies, Australian government institutions, and universities, using a range of instruments. Sedimentary rocks that contain organic matter are typically referred to as source rocks (e.g., organic-rich shale, oil shale and coal) and the organic matter within the rock matrix that is insoluble in organic solvents is named kerogen. Data includes the borehole or field site location, sample depth, stratigraphy, analytical methods, other relevant metadata, and various data types including; elemental composition, and the stable isotopes of carbon, hydrogen, nitrogen, and sulfur. Results are also included from methods that separate the extractable organic matter (EOM) from rocks into bulk components, such as the quantification of saturated hydrocarbon, aromatic hydrocarbon, resin and asphaltene (SARA) fractions according to their polarity. The stable carbon (¹³C/¹²C) and hydrogen (²H/¹H) isotopic ratios of the EOM and derivative hydrocarbon fractions, as well as fluid inclusion oils, are presented in delta notation (i.e., &delta;¹³C and &delta;²H) in parts per mil (‰) relative to the Vienna Peedee Belemnite (VPDB) standard.</div><div><br></div><div>These data are used to determine the molecular and isotopic compositions of organic matter within rocks and associated fluid inclusions and evaluate the potential for hydrocarbon generation in a basin. Some data are generated in Geoscience Australia’s laboratory and released in Geoscience Australia records. Data are also collated from destructive analysis reports (DARs), well completion reports (WCRs), and literature. The bulk data for sedimentary rocks are delivered in the Source Rock Bulk Properties and Stable Isotopes web services on the Geoscience Australia Data Discovery Portal at https://portal.ga.gov.au which will be periodically updated.</div>

<div>The Gas Chromatography-Mass Spectrometry (GC-MS) biomarker database table contains publicly available results from Geoscience Australia's organic geochemistry (ORGCHEM) schema and supporting oracle databases for the molecular (biomarker) compositions of source rock extracts and petroleum liquids (e.g., condensate, crude oil, bitumen) sampled from boreholes and field sites. These analyses are undertaken by various laboratories in service and exploration companies, Australian government institutions and universities using either gas chromatography-mass spectrometry (GC-MS) or gas chromatography-mass spectrometry-mass spectrometry (GC-MS-MS). Data includes the borehole or field site location, sample depth, shows and tests, stratigraphy, analytical methods, other relevant metadata, and the molecular composition of aliphatic hydrocarbons, aromatic hydrocarbons and heterocyclic compounds, which contain either nitrogen, oxygen or sulfur.</div><div><br></div><div>These data provide information about the molecular composition of the source rock and its generated petroleum, enabling the determination of the type of organic matter and depositional environment of the source rock and its thermal maturity. Interpretation of these data enable the determination of oil-source and oil-oil correlations, migration pathways, and any secondary alteration of the generated fluids. This information is useful for mapping total petroleum systems, and the assessment of sediment-hosted resources. Some data are generated in Geoscience Australia’s laboratory and released in Geoscience Australia records. Data are also collated from destructive analysis reports (DARs), well completion reports (WCRs), and literature. The biomarker data for crude oils and source rocks are delivered in the Petroleum and Rock Composition – Biomarker web services on the Geoscience Australia Data Discovery Portal at https://portal.ga.gov.au which will be periodically updated.</div>

<div>The bulk oils database table contains publicly available results from Geoscience Australia's organic geochemistry (ORGCHEM) schema and supporting oracle databases for the bulk properties of petroleum liquids (e.g., condensate, crude oil, bitumen) sampled from boreholes and field sites. The analyses are performed by various laboratories in service and exploration companies, Australian government institutions, and universities using a range of instruments. Petroleum is composed primarily of hydrocarbons (carbon and hydrogen) with minor quantities of heterocyclic compounds containing either nitrogen, oxygen or sulfur. Data includes the borehole or field site location, sample depth, shows and tests, stratigraphy, analytical methods, other relevant metadata, and various data types including; API gravity, elemental composition and photographs of the samples. The stable carbon (¹³C/¹²C) and hydrogen (²H/¹H) isotopic ratios of crude oil and derivative saturated and aromatic hydrocarbon fractions are presented in parts per mil (‰) and in delta notation as &delta;¹³C and &delta;²H, respectively. Results are also included from methods that separate crude oils into bulk components, such as the quantification of saturated hydrocarbon, aromatic hydrocarbon, resin, and asphaltene (SARA) fractions according to their polarity.</div><div><br></div><div>These data provide information about the petroleum fluid’s composition, source, thermal maturity, secondary alteration, and fluid migration pathways. They are also useful for enhanced oil recovery assessments, petroleum systems mapping and basin modelling. Hence, these sample-based datasets are used for the discovery and evaluation of sediment-hosted resources. Some data are generated in Geoscience Australia’s laboratory and released in Geoscience Australia records. Data are also collated from destructive analysis reports (DARs), well completion reports (WCRs), and literature. The bulk oils data are delivered in the Petroleum Bulk Properties and Stable Isotopes web services on the Geoscience Australia Data Discovery Portal at https://portal.ga.gov.au which will be periodically updated.</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 a low emissions economy, strong resources and agriculture sectors, and economic opportunities and social benefits for Australia’s regional and remote communities. The Exploring for the Future program, which commenced in 2016, is an eight year, $225 m investment by the Australian Government. </div><div>As part of this program, Geoscience Australia led two deep crustal reflection seismic surveys in the South Nicholson region, revealing the existence of the Carrara Sub-basin, a large sedimentary depocentre up to 8 km deep, beneath the Georgina Basin (Carr et al., 2019; 2020). The depocentre is believed to contain thick sequences of highly prospective Proterozoic rocks for base metals and unconventional hydrocarbons. To confirm geological interpretations and assess resource potential, the National Drilling Initiative, NDI Carrara 1 stratigraphic drill hole was completed in late 2020, as a collaboration between Geoscience Australia, the Northern Territory Geological Survey (NTGS) and the MinEx CRC (Geoscience Australia, 2021). NDI Carrara 1 is located on the western flank of the Carrara Sub-basin on the South Nicholson seismic line (17GA-SN1) (Figure 1.1; Figure 1.2), reaching a total depth of 1751 m, intersecting sedimentary rocks comprising ca. 630 m of Cambrian calcareous shales of the Georgina Basin and ca. 1100 m of Proterozoic carbonates and siliciclastics that include black shales of the Carrara Sub-basin.</div><div>This report presents data on selected rock samples from NDI Carrara&nbsp;1, conducted by the Mawson Analytical Spectrometry Services, University of Adelaide, under contract to Geoscience Australia. These results include bulk carbon isotope ratios (δ13C) of bitumens and isolated kerogens. In addition, a selection of 10 samples was analysed at Geoscience Australia for comparison purposes.</div><div><br></div>

<div>The Proterozoic basins of northern Australia have been the focus of regional hydrocarbon prospectivity studies undertaken by the Exploring for the Future&nbsp;program dedicated to increasing investment in resource exploration in northern Australia. As part of this program, a compilation of the compound-specific isotopic compositions of linear alkanes in source extracts, oils and oil stains from 21 boreholes&nbsp;of the greater McArthur Basin has been completed. The samples were analysed in Geoscience Australia’s Isotope and Organic Geochemistry Laboratory and the stable carbon and hydrogen isotopic data of individual alkanes are released in this report. </div>

<div>The onshore Canning Basin in Western Australia was the focus of a regional hydrocarbon prospectivity assessment undertaken by the Exploring for the Future&nbsp;(EFTF) program dedicated to increasing investment in resource exploration in northern Australia, with the objective being to acquire new data and information about the potential mineral, energy and groundwater resources concealed beneath the surface. Significant work has been carried out to deliver new pre-competitive data in the region including new seismic acquisition, drilling of a stratigraphic well, and geochemical analysis from historic exploration wells.</div><div><br></div><div>As part of this program, determination of the molecular and noble gas isotopic composition of natural gases from selected petroleum wells in the Canning Basin were undertaken by Smart Gas Sciences, under contract to Geoscience Australia, with results from these analyses being released in this report. This report provides additional data to determine the sources of natural gases in the Canning Basin and build on the availability of existing gas data, gas-gas correlations and gas-oil correlations. Noble gas isotopic data can be used in conjunction with carbon and hydrogen isotopic data to determine the origin of both inorganic and organic (hydrocarbon) gases. This information can be used in future geological programs to determine the source and distribution of hydrogen and helium in natural gases and support exploration programs.</div>

A regional hydrocarbon prospectivity study was undertaken in the onshore Canning Basin in Western Australia as part of the Exploring for the Future (EFTF) program, an Australian Government initiative dedicated to driving investment in resource exploration. As part of this program, significant work has been carried out to deliver new pre-competitive data including new seismic acquisition, drilling of stratigraphic wells and the geochemical analysis of geological samples recovered from exploration wells. A regional, 872 km long 2D seismic line (18GA-KB1) acquired in 2018 by Geoscience Australia (GA) and the Geological Survey of Western Australia (GSWA), images the Kidson Sub-basin of the Canning Basin. In order to provide a test of geological interpretations made from the Kidson seismic survey, a deep stratigraphic well, Barnicarndy 1, was drilled in 2019 in partnership between Geoscience Australia (GA) and the Geological Survey of Western Australia (GSWA) in the Barnicarndy Graben, 67 km west of Telfer, in the South West Canning Basin. Drilling recovered about 2100 m of continuous core from 580 mRT to the total driller’s depth (TD) of 2680.53 mRT (Normore and Rapaic, 2020). An extensive analytical program was carried out to characterise the lithology, age and depositional environment of these sediments. This included detailed organic geochemistry including isotopic and biomarker analyses of core samples. In order to determine the possible presence of organic contaminants in core samples that may jeopardise interpretation of results, manufactured products used during drilling and sample processing were identified as potential sources of hydrocarbon contamination and were investigated for their hydrocarbon content. In addition, in order to test if any hydrocarbon contamination was occurring due to contact with these manufactured products, water samples from the sumps and surface samples of drill muds from specific depths were collected and analysed as well.