This presentation describes source rock data in addition to new compositional and stable isotopic data for 17 oils and six gases from the Amadeus Basin, central Australia. All data was analysed and interpreted by Geoscience Australia. The results of this study provide new insights into the origin and preservational history of hydrocarbons in the basin and provide a platform for future research directions.

The hydrocarbon generative potential and the thermal maturity of source rocks in the offshore northern Perth Basin was reassessed based on existing and new geochemical data to get a better understanding of the basin's prospectivity. The study establishes for the first time that the main source of onshore accumulations, the Late Permian-Early Triassic Hovea Member, is well developed offshore and contains organic-rich sediments of oil-prone character. This finding shatters the long-held view that the Hovea Member was either absent or of poor quality offshore and provides a new perspective on the basin's prospectivity. The source potential of the Hovea Member varies spatially with best source rocks observed in the Beagle Ridge and Central Abrolhos Sub-basin. The Late Permian Irwin River Sequence and several Jurassic Sequences are also identified as prime potential source rocks offshore, mostly for their gas-generative potential. Oil-generative potential was identified in the Middle to Late Jurassic Yarragadee Sequence and possibly in the Middle Jurassic Cadda Sequence.

The Browse Basin, located offshore on Australia's North West Shelf, contains major natural gas accumulations, some of which present high abundances of helium. The basin also contains large quantities of CO2 with some wells containing up to ~18 mol% CO2. Currently there is no information as to the origins of He and CO2 within the Browse Basin, despite this providing important information to the evolution of the natural gas. By understanding where components of the gas originate, it is possible to make predictions about areas that may be high in CO2, which would be problematic for production; conversely areas rich in He could present a second revenue stream from the same well.

<b>IMPORTANT NOTICE: </b>This web service has been deprecated. The Australian Onshore and Offshore Boreholes OGC service at https://services.ga.gov.au/gis/boreholes/ows should now be used for accessing Geoscience Australia borehole data. This is an Open Geospatial Consortium (OGC) web service providing access to a subset of Australian geoscience samples data held by Geoscience Australia. The subset currently relates specifically to Australian Boreholes.

This database contains geochemical data for samples analysed both for inorganic and organic geochemistry. Analytical data are sourced from Geoscience Australia's Inorganic Geochemistry Database (OZCHEM) and Organic Geochemistry Database (ORGCHEM), respectively. The data are joined on a unique sample number. Inorganic geochemical data cover the majority of the periodic table, with metadata on analytical methods and detection limits. Organic geochemical data include results of pyrolysis, derivative calculated values, and, where available, isotopic composition of carbonates (D13C) and isotopic composition of rock nitrogen (D15N). Further, there are provisions for delivery of isotopic data for kerogen (H, C, N) and oxygen (O) for carbonates. Where available, sample descriptions include stratigraphic unit names and ages, and lithology. Location information includes coordinates of the sampled feature (eg, borehole), coordinates of the sample and sample depth. Interpretation of the combined inorganic and organic geochemistry for organic-rich shales will facilitate comprehensive characterisation of hydrocarbons source rocks and mineral commodities source and trap environments. All are achieved within the frameworks of petroleum and mineral systems analysis. The initial data delivered by this service include 1785 samples from 35 boreholes from 14 geological provinces, including recently released data for 442 samples from the South Nicholson National Drilling Initiative Carrara 1 stratigraphic drill hole (Butcher et al., 2021; Carson et al., 2021). Many sampled boreholes are located within the polygon of the Exploring for the Future Barkly-Isa-Georgetown project. This dataset will be updated periodically as more data become available.

The Roebuck Basin on Australia’s offshore north-western margin is the focus of a regional hydrocarbon prospectivity assessment being undertaken by the Offshore Energy Systems Section. This offshore program is designed to produce pre-competitive information to assist with the evaluation of the hydrocarbon resource potential of the central North West Shelf and attract exploration investment to Australia. The recent oil and gas discoveries at Phoenix South 1 (2014), Roc 1 (2015-16), Roc 2 (2016), Phoenix South 2 (2016), Phoenix South 3 (2018), Dorado 1 (2018) and Dorado 2–3 (2019) in the Bedout Sub-basin demonstrate the presence of a petroleum system in Lower Triassic strata (Grosjean et al., 2021; Rollet et al., 2019). As part of this program, a range of organic geochemical analyses were acquired on petroleum fluids from the Dorado 1 and Roc 2 wells with these data released in this report.

In 2014, the surprise discovery of oil in the well Phoenix South 1 on Australia’s North West Shelf (NWS) heralded the Bedout Sub-basin as Australia’s new petroleum province. The well had initially targeted gas in Triassic reservoirs of the Keraudren Formation and Locker Shale but unexpectedly encountered oil instead. This has fuelled a revival of exploration in the area with subsequent wells Roc 1, Roc 2, Phoenix South 2 and Dorado 1 all successful in penetrating hydrocarbon columns. The Phoenix South 1 accumulation is significant as it demonstrates the occurrence of an effective oil-prone source rock within the Lower–Middle Triassic for the first time on the NWS. It also raised the possibility that a source rock analogue to the Hovea Member of the Lopingian–Lower Triassic Kockatea Shale, a well-established source of oil and gas in the northern Perth Basin, may also be effective on the NWS. In order to understand the origin of the Phoenix South 1 accumulation, its geochemical composition was compared to those of Triassic-sourced oils from the Perth Basin and petroleum fluids from the neighbouring Browse Basin, and Beagle and Dampier sub-basins.

<p>The Roebuck Basin on Australia’s offshore north-western margin is the focus of a regional hydrocarbon prospectivity assessment being undertaken by the North West Margin Energy Studies Section (NWMES). This offshore program is designed to produce pre-competitive information to assist with the evaluation of the hydrocarbon resource potential of the central North West Shelf and attract exploration investment to Australia. <p>The recent oil and gas discoveries at Phoenix South 1 (2014), Roc 1 (2015-16), Roc 2 (2016), Phoenix South 2 (2016), Phoenix South 3 (2018) and Dorado 1 (2018) in the Bedout Sub-basin demonstrate the presence of a petroleum system in Lower Triassic strata. The current study aims to better understand this new petroleum system and establish its extent. <p>As part of this program, compositional and isotopic analyses were undertaken by Geoscience Australia on gas samples from the wells Roc 1 and Roc 2 and data from these analyses are released in this dataset.

Hydrochemistry data for Australian groundwater, including field and laboratory measurements of chemical parameters (electrical conductivity (EC), potential of hydrogen (pH), redox potential, and dissolved oxygen), major and minor ions, trace elements, nutrients, pesticides, isotopes and organic chemicals. < <b>Value: </b>The chemical properties of groundwater are key parameters to understand groundwater systems and their functions. Groundwater chemistry information includes the ionic and isotopic composition of the water, representing the gases and solids that are dissolved in it. Hydrochemistry data is used to understand the source, flow, and interactions of groundwater samples with surface water and geological units, providing insight into aquifer characteristics. Hydrochemistry information is key to determining the quality of groundwater resources for societal, agricultural, industrial and environmental applications. Insights from hydrochemical analyses can be used to assess a groundwater resource, the impact of land use changes, irrigation and groundwater extraction on regional groundwater quality and quantity, assess prospective mineral exploration targets, and determine how groundwater interacts with surface water in streams and lakes. <b>Scope: </b>The database was inaugurated in 2016 with hydrochemical data collected over the Australian landmass by Geoscience Australia and its predecessors, and has expanded with regional and national data. It has been in the custodianship of the hydrochemists in Geoscience Australia's Minerals, Energy and Groundwater Division and its predecessors. Explore the <b>Geoscience Australia portal - https://portal.ga.gov.au/</b>

<b> Legacy service retired 29/11/2022</b> This is an Open Geospatial Consortium (OGC) web service providing access to Australian onshore and offshore borehole data conforming to the GeoSciML version 4.0 specification. The borehole data includes Mineral Drillholes, Petroleum Wells and Water Bores along with a variety of others types. The dataset has been restricted to onshore and offshore Australian boreholes, and bores that have the potential to support geological investigations and assessment of a variety of resources.