<b>Organic Geochemistry (ORGCHEM) Schema. Australian Source Rock and Fluid Atlas</b> The databases tables held within Geoscience Australia's Oracle Organic Geochemistry (ORGCHEM) Schema, together with other supporting Oracle databases (e.g., Borehole database (BOREHOLE), Australian Stratigraphic Units Database (ASUD), and the Reservoir, Facies and Shows (RESFACS) database), underpin the Australian Source Rock and Fluid Atlas web services and publications. These products provide information in an Australia-wide geological context on organic geochemistry, organic petrology and stable isotope data related primarily to sedimentary rocks and energy (petroleum and hydrogen) sample-based datasets used for the discovery and evaluation of sediment-hosted resources. The sample data provide the spatial distribution of source rocks and their derived petroleum fluids (natural gas and crude oil) taken from boreholes and field sites in onshore and offshore Australian provinces. Sample depth, stratigraphy, analytical methods, and other relevant metadata are also supplied with the analytical results. Sedimentary rocks that contain organic matter are 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. The data in the ORGCHEM schema are produced by a wide range of destructive analytical techniques conducted on samples submitted by industry under legislative requirements, as well as on samples collected by research projects undertaken by Geoscience Australia, state and territory geological organisations and scientific institutions including the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and universities. Data entered into the database tables are commonly sourced from both the basic and interpretive volumes of well completion reports (WCR) provided by the petroleum well operator to either the state and territory governments or, for offshore wells, to the Commonwealth Government under the Offshore Petroleum and Greenhouse Gas Storage Act (OPGGSA) 2006 and previous Petroleum (submerged Lands) Act (PSLA) 1967. Data are also sourced from analyses conducted by Geoscience Australia’s laboratory and its predecessor organisations, the Australian Geological Survey Organisation (AGSO) and the Bureau of Mineral Resources (BMR). Other open file data from company announcements and reports, scientific publications and university theses are captured. The ORGCHEM database was created in 1990 by the BMR in response to industry requests for organic geochemistry data, featuring pyrolysis, vitrinite reflectance and carbon isotopic data (Boreham, 1990). Funding from the Australian Petroleum Cooperative Research Centre (1991–2003) enabled the organic geochemical data to be made publicly available at no cost via the petroleum wells web page from 2002 and included BOREHOLE, ORGCHEM and the Reservoir, Facies and Shows (RESFACS) databases. Investment by the Australian Government in Geoscience Australia’s Exploring for the Future (EFTF) program facilitated technological upgrades and established the current web services (Edwards et al., 2020). The extensive scope of the ORGCHEM schema has led to the development of numerous database tables and web services tailored to visualise the various datasets related to sedimentary rocks, in particular source rocks, crude oils and natural gases within the petroleum systems framework. These web services offer pathways to access the wealth of information contained within the ORGCHEM schema. Web services that facilitate the characterisation of source rocks (and kerogen) comprise data generated from programmed pyrolysis (e.g., Hawk, Rock-Eval, Source Rock Analyser), pyrolysis-gas chromatography (Py-GC) and kinetics analyses, and organic petrological studies (e.g., quantitation of maceral groups and organoclasts, vitrinite reflectance measurements) using reflected light microscopy. Collectively, these data are used to establish the occurrence of source rocks and the post-burial thermal history of sedimentary basins to evaluate the potential for hydrocarbon generation. Other web services provide data to characterise source rock extracts (i.e., solvent extracted organic matter), fluid inclusions and petroleum (e.g., natural gas, crude oil, bitumen) through the reporting of their bulk properties (e.g., API gravity, elemental composition) and molecular composition using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Also reported are the stable isotope ratios of carbon, hydrogen, nitrogen, oxygen and sulfur using gas chromatography-isotope ratio mass spectrometry (GC-IRMS) and noble gas isotope abundances using ultimate high-resolution variable multicollection mass spectrometry. The stable isotopes of carbon, oxygen and strontium are also reported for sedimentary rocks containing carbonate either within the mineral matrix or in cements. Interpretation of these data enables the characterisation of petroleum source rocks and identification of their derived petroleum fluids, which comprise two key elements of petroleum systems analysis. Understanding a fluid’s physical properties and molecular composition are prerequisites for field development. The composition of petroleum determines its economic value and hence why the concentration of hydrocarbons (methane, wet gases, light and heavy oil) and hydrogen, helium and argon are important relative to those of nitrogen, carbon dioxide and hydrogen sulfide for gases, and heterocyclic compounds (nitrogen, oxygen or sulfur) found in the asphaltene, resin and polar fractions of crude oils. The web services and tools in the Geoscience Australia Data Discovery Portal (https://portal.ga.gov.au/), and specifically in the Source Rock and Fluid Atlas Persona (https://portal.ga.gov.au/persona/sra), allow the users to search, filter and select data based on various criteria, such as basin, formation, sample type, analysis type, and specific geochemical parameters. The web map services (WMS) and web feature services (WFS) enable the user to download data in a variety of formats (csv, Json, kml and shape file). The Source Rock and Fluid Atlas supports national resource assessments. The focus of the atlas is on the exploration and development of energy resources (i.e., petroleum and hydrogen) and the evaluation of resource commodities (i.e., helium and graphite). Some data held in the ORGCHEM tables are used for enhanced oil recovery and carbon capture, storage and utilisation projects. The objective of the atlas is to empower people to deliver Earth science excellence through data and digital capability. It benefits users who are interested in the exploration and development of Australia's energy resources by: • Providing a comprehensive and reliable source of information on the organic geochemistry of Australian source rocks • Enhancing the understanding of the spatial distribution, quality, and maturity of petroleum source rocks. • Facilitating the mapping of total petroleum and hydrogen systems and the assessment of the petroleum and hydrogen resource potential and prospectivity of Australian basins. • Facilitating the mapping of gases (e.g., methane, helium, carbon dioxide) within the geosphere as part of the transition to clean energy. • Enabling the integration and comparison of data from diverse sources and various acquisition methods, such as geological, geochemical, geophysical and geospatial data. • Providing data for integration into enhanced oil recovery and carbon capture, storage and utilisation projects. • Improving the accessibility and usability of data through user-friendly and interactive web-based interfaces. • Promoting the dissemination and sharing of data among Government, industry and community stakeholders. <b>References</b> Australian Petroleum Cooperative Research Centre (APCRC) 1991-2003. Australian Petroleum CRC (1991 - 2003), viewed 6 May 2024, https://www.eoas.info/bib/ASBS00862.htm and https://www.eoas.info/biogs/A001918b.htm#pub-resources Boreham, C. 1990. ORGCHEM Organic geochemical database. BMR Research Newsletter 13. Record 13:10-10. Geoscience Australia, Canberra. https://pid.geoscience.gov.au/dataset/ga/90326 Edwards, D.S., MacFarlane, S., Grosjean, E., Buckler, T., Boreham, C.J., Henson, P., Cherukoori, R., Tracey-Patte, T., van der Wielen, S.E., Ray, J., Raymond, O. 2020. Australian source rocks, fluids and petroleum systems – a new integrated geoscience data discovery portal for maximising data potential. Geoscience Australia, Canberra. http://dx.doi.org/10.11636/133751. <b>Citation</b> Edwards, D., Buckler, T. 2024. Organic Geochemistry (ORGCHEM) Schema. Australian Source Rock and Fluid Atlas. Geoscience Australia, Canberra. https://pid.geoscience.gov.au/dataset/ga/149422

Geoscience Australia's Australian National Hydrocarbon Geochemistry Data Collection comprises Oracle database tables from the Organic Geochemistry (ORGCHEM) schema and derivative information in the Petroleum Systems Summary database (Edwards et al., 2020, 2023; Edwards and Buckler, 2024). The ORGCHEM schema includes organic geochemistry, organic petrology and stable isotope database tables that capture the analytical results from sample-based datasets used for the discovery and evaluation of sediment-hosted resources. A focus is to capture open file data relevant to energy (i.e., petroleum and hydrogen) exploration, including source rocks, crude oils and natural gases from both onshore and offshore Australian sedimentary basins. The database tables also include complementary physical properties and complementary inorganic analyses on sedimentary rocks and hydrocarbon-based earth materials. The data are produced by a wide range of destructive analytical techniques conducted on samples submitted by industry under legislative requirements, as well as on samples collected by research projects undertaken by Geoscience Australia, other government agencies and scientific institutions. Some of these results have been generated by Geoscience Australia, whereas other data are compiled from service company reports, well completions reports, government reports, published papers and theses. The data is non-confidential and available for use by Government, the energy exploration industry, research organisations and the community. The Petroleum Systems Summary database stores the compilation of the current understanding of petroleum systems information, including the statistical evaluation of the analytical data by basin across the Australian continent. <b>Value: </b>These data in the ORGCHEM database tables comprise the raw organic geochemistry, organic petrological and stable isotopic values generated for Australian source rocks, crude oils and natural gases and is the only public comprehensive database at the national scale. The raw data are used as input values to other studies, such as basin analysis, petroleum systems evaluation and modelling, resource assessments, enhanced oil recovery projects, and national mapping projects. Derived datasets and value-add products are created based on calculated values and interpretations to provide information on the subsurface petroleum prospectivity of the Australian continent, as summarised in the Petroleum Systems Summary database. The data collection aspires to build a national scale understanding of Australia's petroleum and hydrogen resources. This data collection is useful to government for evidence-based decision making on sediment-hosted energy resources and the energy industry for de-risking both conventional and unconventional hydrocarbon exploration programs, hydrogen exploration programs, and carbon capture, utilisation and storage programs. <b>Scope: </b>The database initially comprised organic geochemical and organic petrological data on organic-rich sedimentary rocks, crude oils and natural gas samples sourced from petroleum wells drilled in the onshore and offshore Australian continent, including those held in the Australian National Offshore Wells Data Collection. Over time, other sample types (e.g., fluid inclusions, mineral veins, bitumen) from other borehole types (e.g., minerals, stratigraphic including the Integrated Ocean Drilling Program, and coal seam gas), marine dredge samples and field sites (outcrop, mines, surface seepage samples, coastal bitumen strandings) have been analysed for their molecular and stable isotopic chemical compositions and are captured in the databases. The organic geochemical database tables and derivative data compiled in the Petroleum Systems Summary database are delivered by web services and analytical tools in the <a href="https://portal.ga.gov.au/">Geoscience Australia Data Discovery Portal </a> and specifically in the <a href="https://portal.ga.gov.au/persona/sra">Source Rock and Fluid Atlas Persona</a>. These web services enable interrogation of source rock and petroleum fluids data within boreholes and from field sites and facilitate correlation of these elements of the petroleum system within and between basins. <b>Reference</b> Edwards, D.S., Buckler, T., Grosjean, E. & Boreham, C.J. 2024. Organic Geochemistry (ORGCHEM) Database. Australian Source Rock and Fluid Atlas. Geoscience Australia, Canberra. https://pid.geoscience.gov.au/dataset/ga/149422 Edwards, D., Hawkins, S., Buckler, T., Cherukoori, R., MacFarlane, S., Grosjean, E., Sedgmen, A., Turk, R. 2023. Petroleum Systems Summary database. Geoscience Australia, Canberra. https://dx.doi.org/10.26186/148979 Edwards, D.S., MacFarlane, S., Grosjean, E., Buckler, T., Boreham, C.J., Henson, P., Cherukoori, R., Tracey-Patte, T., van der Wielen, S.E., Ray, J., Raymond, O. 2020. Australian source rocks, fluids and petroleum systems – a new integrated geoscience data discovery portal for maximising data potential. Geoscience Australia, Canberra. http://dx.doi.org/10.11636/133751.