Natural gases from all of Australia's major gas provinces have been examined using their molecular and carbon isotopic compositions in order to define source, maturity and secondary alteration processes.

The natural gases are composed of a limited number of individual compounds, mainly of C1-C5 hydrocarbons and non-hydrocarbon compounds (CO2, N2, noble gases etc.). Their compositions and isotopes of single compounds provide critical information to decipher the origin and evolution of natural gases. Efficient analysis of these compounds is paramount for timely application of this important dataset.

The article provides an annula update on Australia's energy scenarion, focussing on offshore oil and gas exploration and production and advertsing the current open acreage release round.

Using numerous illustrations this comprehensive black and white resource describes the formation, trapping and uses of natural gas as a non-renewable energy source. The exploration and recovery methods of gas are described, as are Australia's natural gas potential and environmental issues such as greenhouse gases. This 110 page booklet includes student activities with suggested answers. Suitable for secondary Years 9-12.

Restricted on advice from A. Barrett

2002 and 2003 may well prove to be pivotal years for petroleum exploration in Australia as we endeavour to meet our twin imperatives of finding more oil and using gas. Long term gas supply contracts have been signed with China and a number of key oil discoveries have been made both on and offshore. Deep water wells will be drilled that have the potential to usher in another phase of major oil discovery akin to bonanza of the 1960s, when the first steps into the offshore resulted in billion barrel discoveries in Bass Strait. By the close of the first successful cycle of exploration in Australia (1960 to 1972) all currently producing basins were identified as petroliferous, the major play types had been established and over 60% of Australia?s current oil reserves found. The key drivers of this phase were the access to new basins opened up by the move to offshore exploration and the stimulus to further exploration provided by discovery success. The same drivers are apparent now. Recent discoveries in the Perth, Carnarvon, Otway and Browse basins provide strong indications that a significant new cycle of exploration success is already underway. In many cases these finds represent the largest fields yet found in the basin or at least the largest in the last thirty years. The usual discovery history trend of declining field sizes over time has been turned on its head - clearly demonstrating that many of Australia?s currently producing basins still have a long way to run and encouraging further exploration efforts. Perhaps of even more importance to Australia?s long term liquids self sufficiency is the current deepwater drilling campaign which is stepping out beyond former geographic limits. The first wells in major Mesozoic depocentres on the outer margin of the North west Shelf and in the Great Australian Bight are being drilled with the potential to establish entirely new petroleum provinces.

February 2001 Bonaparte Basin - Gas Data The gas database contains molecular compositional and isotopic data for gases from the Bonaparte Basin as exported from AGSO's Orgchem database on 6th February 2001. The output represents those gases for which the data is considered not to be "commercial-in-confidence". Also included is a document which gives a description of the data fields. Copyright (C) Commonwealth of Australia, 2000.

Molecular and stable isotopic (carbon and hydrogen) analyses are being undertaken on fluid samples from offshore Australian gas accumulations, as part of a Geoscience Australia initiative to understand the origin, thermal maturity and degree of preservation of these economic resources. The geochemical data are available from Geoscience Australia's web site http://www.ga.gov.au/oracle/apcrc. Here, emphasis is placed upon documenting the natural gas compositions of the Exmouth Plateau and Exmouth Sub-basin (Fig. 1). It is apparent from the isotopic signatures of the non-combustible and combustible gases that several sources of gas are mixed within these accumulations, many of which have complex fill histories. These results were presented at the Combined National Conference of the Australian Organic Geochemists and the Natural Organic Matter Interest Group, Rottnest Island, Perth, WA, February 2006 (Edwards et al., 2006).

This Oil and Gas Resources of Australia 2008 publication is the successor to Oil and Gas Resources of Australia 2007 and continues as the definitive reference on exploration, development and production of Australia's petroleum resources. The tables describe: - wells drilled - seismic surveys - petroleum discoveries - petroleum reserves - production and development, including forecasts of crude oil and condensate from 2009 to 2025 and a listing of offshore facilities

A range of geophysical indicators have been used to infer the presence of shallow gas in the Arafura Sea. The existence of shallow gas has been confirmed by the analysis of core material obtained during the survey. This sampled gas has a microbial origin related to decay of organic matter in Holocene mud-filled channels. However, geophysical data indicates that another source of gas exists in deeper parts of the sedimentary section and this gas appears to be migrating up from depth. Intense pockmark fields (~350/km2) are often developed above the mud-filled channels but they have also been recorded away from these channels. The development and density of the pockmark fields appears to be related to sea bed sediment type, microbial gas production within the mud-filled channels and supply of fluids from deeper within the sedimentary section. Correlation of sub-bottom profile data with conventional seismic data also indicates that there are links between deep first-order Proterozoic faults, second-order Jurassic faults and third-order faults to sea bed observed in sub-bottom profiles. The detailed sea bed mapping carried out during the survey has also shown correlations between habitat and biodiversity of various benthic fauna. Areas of high biodiversity and abundance generally correlated with harder substrates. In these areas, sea whips and fans, soft corals, hydroids, crinoids and octocorals were frequently identified, with sessile benthos extending up to ~50cm in height. The extensive areas of soft substrate commonly exhibited low-relief benthos which often covered less than 5% of the surface area. Such areas were also frequently noted for pockmark fields and the general uniformity of the environment.