Surprisingly few natural hydrocarbon seeps have been identified in Australia's offshore basins despite studies spanning thirty years. Initial studies of natural hydrocarbon seepage around the Australian margin were generally based around the geochemical analysis of stranded bitumens, water column geochemical `sniffer' sampling, synthetic aperture radar or airborne laser fluorsensor. Later studies involved the integration of these remote sensing and geochemical techniques with mutli-channel and shallow seismic. A review of these earlier studies indicates that many seepage interpretations need to be re-evaluated and that previous data sets, when set in a global context, often represent normal background hydrocarbon levels. Relatively few sites of proven natural hydrocarbon seepage in Australia's offshore sedimentary basins can be reconciled with the dominantly passive margin setting and low recent sedimentation rates, which are not favourable for high rates of seepage, and difficulties in proving seepage on high energy, shallow carbonate shelves, where seabed features may be rapidly reworked and modern marine signatures are overprinted on authigenic seep carbonates. Active thermogenic methane seepage on the Yampi Shelf, the only proven documented occurrence in Australia, is driven by deposition of a thick Late Tertiary carbonate succession and Late Miocene tectonic reactivation. Therefore, to increase the success of detecting and correctly interpreting natural hydrocarbon seepage, data need to be analysed and integrated within the context of the local geological setting, and with an understanding of what is observed globally.

This publication is the sucessor to Oil and Gas Resources 2000 and continues as the definitive reference on exploration, development and production of Australia's petroleum resources. It covers exploration, reserves, undiscovered resources, development, production and supporting information and statistics. It includes a forecast of Australia's crude oil and condensate production from 2001 to 2015, and sustainability indicators for petroleum resources. Information on Australia's petroleum data availability is also included. A revised estimate of Australia's undiscovered resources is included. The Appendices describe wells drilled and seismic surveys carried out in 2001. There is also a chronological listing of offshore and onshore oil and gas discoveries to 2001, listings of all petroleum platforms and pipelines, and a map showing all Australian petroleum exploration and development titles, with a key of title holders and interests as at March 2001. OGRA 2001 provides the background for much of the advice on petroleum resources given to the Australian government and is a key source for petroleum exploration, production and service companies, petroleum engineers and geologists, energy analysts, stockbrokers and share investors.

This publication is the successor to Oil and Gas Resources of Australia 2002 and continues as the definitive reference on exploration, development and production of Australia's petroleum resources. It covers exploration, reserves, opportunity for growth of oil and gas resources, development, coalbed methane resources, production, crude oil and shale oil and supporting information and statistics. It includes a forecast of Australia's crude oil and condensate production from 2004 to 2025, and sustainability indicators for petroleum resources. Information on Australia's petroleum data availability is also included and an estimate of Australia's undiscovered oil and gas potential and a review of developments in geological sequestration of carbon dioxide. The Appendices describe wells drilled and seismic surveys carried out in 2003. There is also a chronological listing of offshore and onshore oil and gas discoveries to 2003 listings of all petroleum platforms and pipelines, and a map showing all Australian petroleum exploration and development titles, with a key of title holders and interests as at March 2004. OGRA 2003 provides the background for much of the advice on petroleum resources given to the Australian government and is a key source for petroleum exploration, production and service companies, petroleum engineers and geologists, energy analysts, stockbrokers and share investors.

This report contains data on the 68 petroleum accumulations discovered in the Bonaparte Basin to December 2002. It provides summaries of the regional setting, evolution and stratigraphy of the basin and discusses the hydrocarbon habitat and development of the producing accumulations. For the purpose of this report, a discrete, measured recovery of petroleum on test from an exploration well qualifies as a `discovery?. Petroleum accumulations inferred from wireline log interpretations (and where petroleum has not been recovered on test) are referred to as `shows?. Small quantities of gas recovered on test in three wells included in this report may represent `solution gas? - indicating these wells may not have intersected a petroleum pool.

This publication is the successor to Oil and Gas Resources of Australia 2001 and continues as the definitive reference on exploration, development and production of Australia's petroleum resources. OGRA 2002 provides the background for much of the advice on petroleum resources given to the Australian Government.

The spectral signature of an about 1 micrometer thick oil slick has been identified from airborne hyperspectral data (HyMap sensor) acquired over a floating oil production facility located on the North West Shelf of Australia. The paper describes spectral characteristrics of the signature and identifies conditions in which it can be observed.

Few published studies have demonstrated that coals have sourced significant volumes of oil, while none have clearly implicated coals in the Australian context. This paper presents strong geochemical evidence for coals being the source for the sub-economic oil accumulations in the Bass Basin. Oils in the Bass Basin form a single oil population. Biodegradation of Cormorant oil results in a separate oil family compared to Pelican and Yolla crudes. Oil-to-source correlation based on biomarkers and carbon isotopes shows that the Early Eocene to Palaeocene coals are effective source rocks in the Bass Basin. This is in contrast to previous work which favoured disseminated organic matter in claystone as the sole source (Miyazaki, 1995). Potential oil-prone source rocks in the Bass Basin are the early Tertiary coals, mainly concentrated in the Middle to Early Eocene succession. These coals have hydrogen indices (HI) up to 500 mg HC/gTOC) and are associated with disseminated organic matter in claystones that are mainly gas prone. Maturity is sufficient for oil and gas generation with vitrinite reflectance (VR) up to 1.8 % at base of Pelican-5. Igneous intrusions, mainly within Palaeocene, Oligocene and Miocene sediments, produce localised elevated maturity to 5 % VR. The key events in the process of petroleum generation and migration from the effective coaly source rocks in the Bass Basin are: (i) the onset of oil generation at a VR of 0.65 % (2450m in Pelican-5); (ii) the onset of expulsion (primary migration) at a VR of 0.75 % (2700 to 3200m in Bass Basin; 2850m in Pelican-5); (iii) the main oil window between VR of 0.75 % and 0.95 % (2850-3300m in Pelican-5); and, (iv) the main gas window at VR >1.2 % (>3650m in Pelican-5).

The North West Margin Transects Cruise is part of a program being undertaken by AGSO to determine the structural architecture of the north-western margin of Australia and the influence of structuring on the location, migration and trapping ofhydrocarbons in the region. An important aspect of this program is the acquisition ofa series of full margin 'dip' transects extending from unrifted cratonic basement tobeyond the continent-ocean boundary, and at least two 'strike' transects that willextend along the full length of the shelf from the eastern Timor Sea to North WestCape. The major objective of the proposed cruise is to extend previous AGSO deepseismic surveys across the Browse (Survey 119), offshore Canning (SNOWS-3/Survey 120) and northern Carnarvon Basins (SNOWS-/Survey 101, SNOWS-2/Survey 110) to complete these margin transects. Specific objectives of theproposed survey are: *Determine the regional structural framework of the Scott Plateau area and itsrelationship to adjacent features such as the Argo Abyssal Plain, the BrowseBasin and the Rowley Sub-Basin of the offshore Canning Basin; *Determine the regional structural framework of the Exmouth Plateau and itsrelationship to adjacent features such as the Barrow-Dampier Sub-basin, and theArgo and Gascoyne Abyssal Plains. *Define the broad deep-crustal structure of the region and develop a modelexplaining the tectonic, subsidence and thermal history of the Scott Plateau andthe Exmouth Plateau in relation to the development of the continental margin andadjacent ocean basins. *Assess the effects of the deep crustal structures and their reactivation phases onthe development of known petroleum accumulations. To address these objectives it is proposed that RV Rig Seismic be used to acquireabout 3276 km of deep crustal (16 second record length) multichannel seismic andother geophysical data along 9 transects across the outer margins of the Browse,offshore Canning and northern Carnarvon Basins. The survey will tie into the 1991SNOWS-1 (101), 1992 SNOWS-2 (110), 1993 Browse Basin (119) and SNOWS-3(120) surveys.

Numerous Miocene reefs and build-ups have been identified in the Rowley Shoals region of the central North West Shelf, offshore Western Australia. The reefs form part of an extensive Miocene reef tract over 1600 km long, which extended northward into the Timor Sea and southwards to North West Cape. Growth of the vast majority of these Miocene reefs failed to keep pace with relative sea-level changes in the latest Miocene, whereas reef growth continued on the central North West Shelf to form the three present-day atolls of the Rowley Shoals (Mermaid, Clerke and Imperieuse Reefs). Widespread buildups and atoll reefs developed in the Rowley Shoals region in the Middle Miocene, and their internal stacking geometries indicate successive aggradational, progradational and back-stepping growth phases that are correlated with eustatic sea-level fluctuations. Growth of the majority of the Miocene reefs ceased at a major sea-level fall in the late Late Miocene, and only the reefs of the present-day Rowley Shoals continued to grow after this event. The Rowley Shoals reefs continued to keep pace with Pliocene-Pleistocene sea level changes, whereas the surrounding shelf subsided to depths of 230-440 m. Contrary to previous hypotheses, we find no direct evidence that active, or palaeo, hydrocarbon seepage triggered or controlled growth of the Rowley Shoals reefs or their buried Miocene predecessors. Rather we conclude that initial reef growth was controlled by transpressional reactivation and structuring of the Mermaid Fault Zone during the early stage of collision between the Australia and Asian plates.

This report is an annual report which provides information and statistics on Australia's oil and gas resources. The statistics in this report include data for the calendar year 1999.