Seismic data, calibration and State of Health files. 2005-2007

This service includes world bathymetry, elevation (hillshade), and satellite imagery data, and ocean, country, population and natural features. The information was derived from various sources, including Natural Earth and Landsat Imagery. It is a cached service with a Web Mercator Projection. The service contains layer scale dependencies.

From the beginning of petroleum exploration in the Perth Basin, the importance of the Early Triassic marine Kockatea Shale was recognised as the principal source for liquid petroleum in the onshore northern Perth Basin (Powell and McKirdy, 1976). Thomas and Barber (2004) constrained the effective source rock to a Early Triassic, middle Sapropelic Interval in the Hovea Member of the lower Kockatea Shale. In addition, Jurassic and Permian sourced-oils (Summons et al., 1995) demonstrate local effective non-Kockatea source rocks. However, evidence for multiple effective gas source rocks is limited. This study utilizes the molecular composition and carbon and hydrogen isotopic compositions of 34 natural gases from the Perth Basin, extending the previous study (Boreham et al., 2001) to the offshore and includes hydrogen isotopes and gases. It shows the existence of Jurassic to Permain gas systems in the Perth Basin.

ORIGIN AND USE OF HELIUM IN AUSTRALIAN NATURAL GASES C. Boreham1, D. Edwards1. R. Poreda2, P. Henson1. 1 Geoscience Australia, Canberra, Australia; 2 University of Rochester, NY, USA Over 800 natural gases representative of Australia's hydrocarbon-producing sedimentary basins have been analyzed for their helium (He) content and around 150 gases for their helium isotopic composition, supplemented by isotopic compositions of the higher noble gases. Australian natural gases have helium abundances to over 10%, with the highest values in the Amadeus Basin, in central Australia, while 3He/4He ratios range from around 0.01 to 4.2 Ra (Figure 1). The onshore Gunnedah Basin of southeastern Australia and the offshore Bass and onshore/offshore Otway basins in southern Australia show the highest 3He/4He ratios, indicating a significant mantle contribution. Interestingly, the offshore Gippsland Basin, adjacent to the Bass Basin, has slightly lower 3He/4He ratios. In the Gunnedah Basin, the associated CO2 has a relatively low abundance compared to extreme concentrations of CO2 in some Otway Basin wells, which are associated with recent volcanism. The onshore Bowen and Cooper basins of eastern Australia, where natural gases are predominately sourced from Permian coals, show intermediate 3He/4He ratios with the former having a higher mantle contribution. At the other end of the spectrum, low 3He/4He ratios characterize natural gases of the offshore North West Shelf (Bonaparte, Browse, Carnarvon) and onshore/offshore Perth basins in northwestern and southwestern Australia, respectively, and radiogenic helium predominates. Hence the sometimes extensive volcanic activity and igneous intrusions in these western basins is not expressed in the helium isotopes. The accompanying high CO2 contents (up to 44%) of some of these North West Shelf gases, together with the carbon isotopic composition of CO2, infer an inorganic source most likely from the thermal decomposition of carbonates. The geochemical data suggest that the origin of helium in Australian natural gas accumulations is region specific and complex with the component gases originating from multiple sources. The relative low CO2/3He ratio for many natural gases indicates a systematic loss of CO2 from most basins. The process by which CO2 has been lost from the system is most likely associated with precipitation of carbonates (Prinzhofer, 2013). The age of the source (and/or reservoir) rock has a primary control on the helium content with radiogenic 4He input increasing with residence time (Figure 1). References: Prinzhofer, A., 2013. Noble gases in oil and gas accumulations. The Noble Gases as Geochemical Tracers. Springer. 225-245.

Interpretation of newly acquired seismic data in the northern Houtman Sub-basin (Perth Basin) suggests the region contains potential source rocks similar to those in the producing Abrolhos Sub-basin. The regionally extensive late Permian–Early Triassic Kockatea Shale has the potential to contain the oil-prone Hovea Member source interval. Large Permian syn-rift half-graben, up to 10 km thick, are likely to contain a range of gas prone source rocks. Further potential source rocks may be found in the Jurassic-Early Cretaceous succession, including the Cattamarra Coal Measures, Cadda shales and mixed sources within the Yarragadee Formation. This study investigates the possible maturity and charge history of these different source rocks. A regional pseudo-3D petroleum systems model is constructed using new seismic interpretations. Heat flow is modelled using crustal structure and possible basement composition determined from potential field modelling, and subsidence analysis is used to investigate lithospheric extension through time. The model is calibrated using temperature and maturity data from 9 wells in the Houtman and Abrolhos sub-basins. Source rock properties are assigned based on an extensive review of TOC, Rock Eval and kinetic data for the offshore northern Perth Basin. Petroleum systems analysis results show that Permian, Triassic and Early Jurassic source rocks may have generated large cumulative volumes of hydrocarbons across the northern Houtman Sub-basin, whilst Middle Jurassic‒Cretaceous sources remain largely immature. However the timing of hydrocarbon generation and expulsion with respect to trap formation and structural reactivation is critical for the successful development and preservation of hydrocarbon accumulations.

This forum showcased the range of pre-competitive geoscience projects currently underway by Geoscience Australia and its collaborative partners under the UNCOVER themes with an emphasis on new projects arising out of the Australian Government’s four year $100M Exploring for the Future program which commenced in late 2016. The themes covered are: Cover and what lies beneath, character and thickness; 3D architecture, mapping the framework for mineral systems; 4D geodynamics and mineral systems of Australia; and, Mineral system footprints and toolkits for explorers

In the present, the GNSS body-fixed reference frame definition is followed according to the International GNSS Service (IGS) conventions [3] which are based on the spacecraft body frame of the GPS Block II/IIA satellites. This definition is also compatible with the GPS Block IIF satellites while in the case of the GPS Block IIR the spacecraft frame is designed with a reverse direction (away from the sun) in the X axis of the body-fixed frame. The situation is similar to the GPS IIA/IIF for the BDS satellites where +X axis points towards the Sun, +Z axis points to the SV’s radius vector towards the Earth’s centre in the antenna boresight direction, and the +Y axis completes the right handed system while it coincides with the rotation axis of the solar panels. The yaw angle is the critical parameter which defines the GNSS attitude. Contrary to GPS and GLONASS, BeiDou Inclined Geosynchronous Orbit (IGSO) and Mean Earth Orbit (MEO) satellites do not experience noon-turn and midnight-turn manoeuvres [6], with the exception of the newly launched IGSO6 or C13, formerly C15 (F. Dilssner and P. Steigenberger personal communication).

This resource contains surface sediment data for Bynoe Harbour collected by Geoscience Australia (GA), the Australian Institute of Marine Science (AIMS) and Department of Land Resource Management (Northern Territory Government) during the period from 2-29 May 2016 on the RV Solander (survey SOL6432/GA4452). This project was made possible through offset funds provided by INPEX-led Ichthys LNG Project to Northern Territory Government Department of Land Resource Management, and co-investment from Geoscience Australia and Australian Institute of Marine Science. The intent of this four year (2014-2018) program is to improve knowledge of the marine environments in the Darwin and Bynoe Harbour regions by collating and collecting baseline data that enable the creation of thematic habitat maps that underpin marine resource management decisions. The specific objectives of the survey were to: 1. Obtain high resolution geophysical (bathymetry) data for outer Darwin Harbour, including Shoal Bay; 2. Characterise substrates (acoustic backscatter properties, grainsize, sediment chemistry) for outer Darwin Harbour, including Shoal Bay; and 3. Collect tidal data for the survey area. Data acquired during the survey included: multibeam sonar bathymetry and acoustic backscatter; physical samples of seabed sediments, underwater photography and video of grab sample locations and oceanographic information including tidal data and sound velocity profiles. This dataset comprises the results of sediment oxygen demand experiments undertaken on seabed sediments. A detailed account of the survey is provided in Siwabessy, P.J.W., Smit, N., Atkinson, I., Dando, N., Harries, S., Howard, F.J.F., Li, J., Nicholas W.A., Picard, K., Radke, L.C., Tran, M., Williams, D. and Whiteway, T., 2016. Bynoe Harbour Marine Survey 2017: GA4452/SOL6432 Post-survey report. Record 2017/04. Geoscience Australia, Canberra. Thanks to the crew of the RV Solander for help with sample collection, Matt Carey, Craig Wintle and Andrew Hislop from the Observatories and Science Support at Geoscience Australia for technical support and Jodie Smith for reviewing the data. This dataset is published with the permission of the CEO, Geoscience Australia

This resource contains surface sediment data for Bynoe Harbour collected by Geoscience Australia (GA), the Australian Institute of Marine Science (AIMS) and Department of Land Resource Management (Northern Territory Government) during the period from 2-29 May 2016 on the RV Solander (survey SOL6432/GA4452). This project was made possible through offset funds provided by INPEX-led Ichthys LNG Project to Northern Territory Government Department of Land Resource Management, and co-investment from Geoscience Australia and Australian Institute of Marine Science. The intent of this four year (2014-2018) program is to improve knowledge of the marine environments in the Darwin and Bynoe Harbour regions by collating and collecting baseline data that enable the creation of thematic habitat maps that underpin marine resource management decisions. The specific objectives of the survey were to: 1. Obtain high resolution geophysical (bathymetry) data for outer Darwin Harbour, including Shoal Bay; 2. Characterise substrates (acoustic backscatter properties, grainsize, sediment chemistry) for outer Darwin Harbour, including Shoal Bay; and 3. Collect tidal data for the survey area. Data acquired during the survey included: multibeam sonar bathymetry and acoustic backscatter; physical samples of seabed sediments, underwater photography and video of grab sample locations and oceanographic information including tidal data and sound velocity profiles. This dataset comprises grain size data measured on seabed sediments. A detailed account of the survey is provided in Siwabessy, P.J.W., Smit, N., Atkinson, I., Dando, N., Harries, S., Howard, F.J.F., Li, J., Nicholas W.A., Picard, K., Radke, L.C., Tran, M., Williams, D. and Whiteway, T., 2016. Bynoe Harbour Marine Survey 2017: GA4452/SOL6432 - Post-survey report. Record 2017/04. Geoscience Australia, Canberra. Thanks to the crew of the RV Solander for help with sample collection, Matt Carey, Craig Wintle and Andrew Hislop from the Observatories and Science Support at Geoscience Australia for technical support and Jodie Smith for reviewing the data. This dataset is published with the permission of the CEO, Geoscience Australia