Legacy product - no abstract available

Legacy product - no abstract available

During April/May 1988, the BMR research vessel 'Rig Seismic' carried out a 21 day geochemical and sedimentological research program in the Otway (17 days) and Gippsland (4 days) Basins. Light hydrocarbon gases (C1-C6) were measured in sediments at 342 locations on thecontinental shelf and upper continental slope. Thermogenic hydrocarbons were identified in near-surface sediments at forty-two locations in the Otway (32) and Gippsland (10) Basins. The major results from the Otway Basin include: 1. Evidence of thermogenic hydrocarbon sediments was found at seven locations on the Crayfish Platform, seven locations on the Mussel Platform and eighteen locations in the VolutaTrough. 2. Wet gas contents ([C2-C4/C1-C4] x 100), which provide some indication of both hydrocarbon source type and maturity,are highest on the basin margins, i.e. the Crayfish and Mussel Platforms. Wet gas contents were consistently lower in the Voluta Trough. 3. Total C1-C4 gas concentrations were higher in the Voluta Trough than on the basin margins, probably because of more intense near-surface faulting in the trough. 4. The geochemical data, when integrated with thermal maturation modelling and well data, suggest that the principal liquidhydrocarbon source rocks are located at the base of the Early Cretaceous Otway Group (i.e. basal Pretty Hill Sandstone). The Late Cretaceous Sherbrook Group appears to be gas-prone. Preliminary data from the Gippsland Basin identify ten locations which show evidence of thermogenic hydrocarbons in near-surface sediments.

The objectives of Project 121.19 were: To understand the deep crustal architecture, the structural reactivation processes and the mechanisms of hydrocarbon generation, migration and entrapment within the Vulcan Sub-Basin, Timor Sea. To achieve the aims of the project, two surveys (Vulcan I & II) were conducted between October and December 1990. This report summarises the results of the Vulcan Sub-Basin I Survey (Survey 97), which focussed on the high resolution seismic and geochemical component of Project 121.19 (i.e. the structural reactivation, hydrocarbon generation and migration theme). The Timor Sea program achieved most of its objectives. The seismic data should, when processed, allow a much better understanding of the nature of the fault reactivation processes in the area. In addition, strike lines run along the Londonderry High show that near-vertical faults appear to correspond with the position of transfer faults which have been inferred from our interpretation of BMR's Timor Sea aeromagnetic data. The geochemical program identified a number of significant hydrocarbon anomalies in the area. The anomalies fell predominantly into two groups. One group was located over, and to the north-east to south-east of the Skua Field, while the other group was associated with transfer faulting, and a major aeromagnetic high, on the edge of the Vulcan Sub-Basin, south-east of Montara 1.

Seismic acquisition for the joint BMR-Woodside Petroleum program in the Dampier Sub-basin started at 0800 am on October 24, 1990 and was completed at 1150 am on Sunday October 28, 1990. A total of 352 km of high resolution seismic data was collected along the 17 agreed survey lines, of which 336 km were full stack data with a total 390 magnetic tapes being used. Data quality appears to be good. In addition to the seismic, a total of 530.6 km of water column geochemical data were also collected.

Legacy product - no abstract available

Legacy product - no abstract available

Legacy product - no abstract available

Invited paper by CEO.

Over the last 10 years there has been a rapid expansion in the coal seam gas industry in Australia. Exploration and production of coal seam gas is primarily focused on sedimentary basins along Australia's eastern seaboard. To provide a sound basis for a national assessment of coal seam gas resources, Geoscience Australia is identifying and mapping the distribution of coal in Australia's onshore sedimentary basins into a single Geographical Information System (GIS). Data are being collated for the three key geological time periods for coal, i.e. the Permian-Triassic, Jurassic-Cretaceous and Cenozoic. Information is being sourced from a wide range of publications and publicly available datasets and includes the distribution, thickness and depth of coal measures, and key attributes such as thermal maturity/rank, water content, porosity/permeability and depositional environment. Other relevant national datasets such as basin polygons, wells, mines and cultural data are also being compiled. While national in scale, work to date has focused on coal measures in the key eastern Australian basins, such as the Permian coals of the Bowen, Gunnedah, Sydney and Galilee basins, and the Jurassic Walloon Coal Measures in the Surat and Clarence-Moreton basins. The GIS forms a fundamental tool for Geoscience Australia's national unconventional hydrocarbon resources assessment. This compilation for the first time provides a single, national-scale coal basins dataset for use by government, industry and the public, reflecting Geoscience Australia's role to improve the information available to support the exploration and management of Australia's hydrocarbon resources.