NDI Carrara 1 is a deep stratigraphic drill hole completed in 2020 as part of the MinEx CRC National Drilling Initiative (NDI) in collaboration with Geoscience Australia and the Northern Territory Geological Survey. It is the first test of the Carrara Sub-Basin, a depocentre newly discovered in the South Nicholson region based on interpretation from seismic surveys (L210 in 2017 and L212 in 2019) recently acquired as part of the Exploring for the Future program. The drill hole intersected approximately 1120 m of Proterozoic sedimentary rocks unconformably overlain by 630 m of Cambrian Georgina Basin carbonates. Continuous cores recovered from 283 m to a total depth of 1750 m provide samples of the highest quality for a comprehensive geochemical program designed to inform on the energy and mineral prospectivity of the Carrara Sub-basin. Total Organic Carbon (TOC) contents from Rock-Eval pyrolysis of the Cambrian and Proterozoic sections demonstrate the potential for several thick black shales as source rocks and unconventional plays. Evidence for retained hydrocarbons included bituminous oil stains in centimetre-scale vugs within the Cambrian Georgina Basin and several oil bleeds within the Proterozoic section. The latter also contains surface gas with up to 2% methane concentrations measured within carbonaceous mudstones. Geochemical analyses of hydrocarbon shows highlight the occurrence of several petroleum systems operating in this frontier region. The results at NDI Carrara 1 offer the promise of a new exciting resource province in northern Australia.

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 a stratigraphic well, 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 a partnership between Geoscience Australia (GA) and the Geological Survey of Western Australia (GSWA) in the Barnicarndy Graben, 67 km west of Telfer, in the southwest Canning Basin. Drilling recovered about 2100 m of continuous core from 580 mRT to the driller’s total depth (TD) of 2680.53 mRT. An extensive analytical program was carried out to characterise the lithology, age and depositional environment of these sediments. This data release presents organic geochemical analyses undertaken on rock extracts obtained from cores selected from the Barnicarndy 1 well. The molecular and stable isotope data carbon and hydrogen will be used to understand the type of organic matter being preserved, the depositional facies and thermal maturity of the Lower Ordovician sedimentary rocks penetrated in this well. This information provides complementary information to other datasets including organic petrological and palynological studies.

Petroleum geochemical datasets and information are essential to government for evidence-based decision making on natural resources, and to the petroleum industry for de-risking exploration. Geoscience Australia’s newly built Data Discovery Portal (https://portal.ga.gov.au/) enables digital discoverability and accessibility to key petroleum geochemical datasets. The portal’s web map services and web feature services allow download and visualisation of geochemical data for source rocks and petroleum fluids, and deliver a petroleum systems framework for northern Australian basins. The Petroleum Source Rock Analytics Tool enables interrogation of source rock data within boreholes and field sites, and facilitates correlation of these elements of the petroleum system within and between basins. The Petroleum Systems Summary Assessment Tool assists the user to search and query components of the petroleum system(s) identified within a basin. The portal functionality includes customised data searches, and visualisation of data via interactive maps, graphs and geoscientific tools. Integration of the petroleum systems framework with the supporting geochemical data enables the Data Discovery Portal to unlock the value of these datasets by affording the user a one-stop access to interrogate the data. This allows greater efficiency and performance in evaluating the petroleum prospectivity of Australia’s sedimentary basins, facilitating and accelerating decision making around exploration investment to ensure Australia’s future resource wealth <b>Citation:</b> Edwards, D.S., MacFarlane, S.K., Grosjean, E., Buckler, T., Boreham, C.J., Henson, P., Cherukoori, R., Tracey-Patte, T., van der Wielen, S., Ray, J. and Raymond, O., 2020. Australian source rocks, fluids and petroleum systems – a new integrated geoscience data discovery portal for maximising data potential. In: Czarnota, K., Roach, I., Abbott, S., Haynes, M., Kositcin, N., Ray, A. and Slatter, E. (eds.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra, 1–4.

Program and Abstracts from the conference

<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, TOC and Rock-Eval pyrolysis analyses were undertaken by Geoscience Australia on selected rock samples from the well Roc 2 to establish their hydrocarbon-generating potential and thermal maturity.

<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.

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.

<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.

<div>NDI Carrara 1 is a deep stratigraphic drill hole completed in 2020 as part of the MinEx CRC National Drilling Initiative (NDI) in collaboration with Geoscience Australia and the Northern Territory Geological Survey. It is the first stratigraphic test of the Carrara Sub-basin, a depocentre newly discovered in the South Nicholson region based on interpretation from seismic surveys (L210 in 2017 and L212 in 2019) acquired as part of the Exploring for the Future program. The drill hole intersected approximately 1120 m of Proterozoic sedimentary rocks unconformably overlain by 630 m of Georgina Basin carbonates.&nbsp;</div><div>Geoscience Australia has undertaken a range of investigations on the lithology, stratigraphy and geotechnical properties of NDI Carrara 1 as well as undertaking a range of analyses of about 500 physical samples recovered through the entire core. Analyses included geochronology, isotope studies, mineralogy, inorganic and organic geochemistry, petrophysics, geomechanics, thermal maturity and petroleum systems investigations.</div><div>Rock-Eval pyrolysis raw data undertaken by Geoscience Australia were reported in Butcher et al. (2021) on selected rock samples to establish their total organic carbon content, hydrocarbon-generating potential and thermal maturity. Interpretation of the Rock-Eval pyrolysis data concluded that a large portion of rocks within the Proterozoic section displayed unreliable Tmax values due to poorly defined S2 peaks resulting from high thermal maturity and low hydrogen content. In order to obtain more reliable Tmax values, Rock-Eval pyrolysis of selected isolated kerogens, where organic matter is concentrated and mineral matrix effects are removed, were conducted and the resulting data are presented in this report.&nbsp;</div><div><br></div>

<div>Scientific studies undertaken on core from the Barnicarndy 1 well drilled in 2019 in the onshore Canning Basin in Western Australia as part of the Exploring for the Future program have shown that the well penetrated a thick section of the early Ordovician Nambeet Formation which contains abundant fossils reflective of deposition in an open marine environment. Although the calcareous shales are organically poor (average total organic carbon content 0.17 wt%) processing of 42 drill core samples recovered a plethora of acid-resistant, organic-walled microfossils. Seven core samples with the highest organic content were analysed for their molecular (biomarker) fossils and stable isotopic composition to provide insights into the type of organic matter preserved, and the redox conditions of the sediments during deposition.</div><div><br></div>This Abstract was submitted/presented to the 2022 Australian Organic Geochemistry Conference 27-29 November (https://events.csiro.au/Events/2022/October/5/Australian-Organic-Geochemistry-Conference)