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  • Summary of GA's plans for marine seismic and reconnaissance surveys off southwestern Australia in 2008/09 as part of the Offshore Energy Security Program

  • An examination of Ordovician conodont faunas from 42 wells in the Canning Basin from which Ordovician conodont faunas have been recovered has been undertaken to provide biostratigraphic control on Ordovician sedimentation in the basin, especially in the WillaraSub-basin and adjacent Broome Arch areas (Table 1). In addition, preliminary conodontbiostratigraphic data from the Prices Creek Ordovician outcrop area on the northern marginof the basin are also mentioned (Nicoll & others, 1993). The recovery of conodont elements from samples is highly variable, and few of the wellshave yielded the abundant faunas that are desirable for biostratigraphic control. However, most wells have provided enough data to establish a generalised conodont based biostratigraphy through the interval from the Nambeet Formation to the top of the NitaFormation. Conodonts in the Bongabinni Formation are of Ordovician age but are not included in a formal zone. A number of the samples appear to have been over-acidised whenoriginally processed. The resulting conodonts are etched and discoloured. This also means that some of the conodonts may have been destroyed in the processing. The possibility exists thatnew processing of some of these samples might result in better control of the section. Material presented includes samples originally prepared and examined by Robert McTavish of WAPET in the 1960's-1970's (McTavish, 1973), samples prepared for Western Mining in the 1980's by Simon Watson (Watson, 1988) and Robert S. Nicoll, determinations by NormanSavage, and material prepared by the Australian Geological Survey (BMR) in the period 1965-1993. Where possible, all previous identifications have been checked for this report. This has not been possible with the samples studied by N.M. Savage (University of Oregon)because the prepared material has not been located. All samples have been examined for thermal maturation using conodont colour alteration and the results indicated on the well summary sheet and against each sample. The stratigraphic determinations used in this report have been drawn from a number of sources. Most have been taken from the well completion reports, but some have beenmodified to conform with revised interpretations of well stratigraphy .

  • Australia's east coast north of Bass Strait has been very sparsely explored for petroleum. Exploration permits have been intermittently held over the offshore Sydney Basin, including an active permit at the time of writing, and some permits were held in north Queensland waters in the 1960s and 1970s, but much of the geology of this eastern continental margin is virtually unknown. This report provides a preliminary assessment of the petroleum potential of Australia's east coast, from the border between New South Wales and Victoria in the south, to the southern boundary of the Great Barrier Reef Marine Park (GBRMP) offshore southeast Queensland in the north. Petroleum exploration is prohibited within the GBRMP, and no assessment of this area is included in the report. Palaeozoic basement rocks covered by a veneer of Cainozoic sediments underlie a large part of the study area (Figure 1). At least four sedimentary basins also underlie the continental shelf and probably the continental slope in the case of the Sydney and Maryborough Basins. These two basins are also the best known; but the Clarence-Moreton and Nambour Basins are also known to have offshore extensions on the shelf. It is also possible but not certain that the Ipswich and Lorne Basins could have offshore components, and there is some evidence of a pre-Clarence-Moreton Basin sedimentary sequence offshore of the Coffs Harbour area. In addition to these basins, several graben and half-graben associated with Tasman Sea rifting may occur within basement dominated shelf and slope areas - two of these features are known from very limited data.

  • The Adavale Basin, in south-central Queensland, contains two dry gas accumulations, Gilmore and Log Creek, discovered in 1964 and 1965. The accumulations occupy fold-related traps in Middle Devonian clastic rocks of the Log Creek Formation and the Lissoy Sandstone. The basin's estimated initial recoverable reserves as at 31 December 1986 comprised 589 x 106 m3 (20.8 x 109 ft3) of sales gas, all in the Gilmore accumulation. The Gilmore gas accumulation was declared economic in August 1987, and gas production is expected to commence in early 1989. Production so far has comprised 10.4 x 106 m3 (366 x 106 ft3) of raw gas, used in the drilling of nearby extension wells.

  • The Gippsland Basin in southeastern Victoria is Australia's major crude oil and natural gas producing province. To the end of 1986 the basin had supplied 88 per cent of Australia's cumulative crude oil production and 48 per cent of cumulative natural gas production. Crude oil and natural gas were first discovered onshore in 1924, near Lakes Entrance, Victoria. Since then over 125 onshore wells have been drilled, resulting in the discovery of one (1) subeconomic and six (6) uneconomic petroleum accumulations. More than 80 exploration and step-out wells have been drilled offshore, resulting in the discovery of eleven (11) economic, twenty-six (26) subeconomic and six (6) uneconomic petroleum accumulations. The petroleum in the Gippsland Basin mainly occupies structural and structural/stratigraphic traps within the Oligocene, Eocene, Paleocene and Late Cretaceous marine, marginal marine and continental clastic sequences. The petroleum is believed to be of land-plant origin; crude oil results from thermal breakdown of exinite, and natural gas from thermal cracking of vitrinite and exinite. The crude oils are generally very light and paraffinic, ranging from 40 to 60oAPI. Some heavier oils discovered at shallow depths range from 14.6 to 26.5oAPI and are thought to have been biologically degraded. The condensates range from 48 to 63oAPI. The natural gases are generally low in condensate content. Some gas reservoirs contain a high proportion of carbon dioxide. Production of natural gas and oil commenced in 1969 and 1970 respectively. Cumulative production to 31 December 1986 was 344.66 x 106m3 of oil, 9.68 x 106m3 of condensate, 41.75 x 106m3 of LPG and 66.14 x 109m3 of sales gas. The oil and gas produced is transported from the twelve offshore production facilities (platforms) by pipeline to gas and crude oil stabilisation plant at Longford, Victoria for processing, and then to storage and distribution centres. Estimated remaining recoverable petroleum reserves in the Gippsland Basin as at 31 December 1986 are 202.44 x 106m3 of oil, 22.44 x 106m3 of condensate, 44.89 x 106m3 of liquid petroleum gas, and 206.39 x 109m3 of sales gas.

  • As at 1 January 1988 the Bonaparte Basin in northwestern Australia contained two economic, nine subeconomic and twenty two uneconomic petroleum accumulations, all of which were discovered since 1959 - all reservoired in sequences ranging from late Palaeozoic to Tertiary in age. The petroleum accumulations of most relevance to petroleum exploration are those located within the Territory of Ashmore and Cartier Islands which are reservoired in rocks of Triassic and Jurassic age. Other less significant accumulations located in the Petrel Sub-basin and Sahul Platform areas of the basin are reservoired in the Permian and Jurassic sequences. The basin's estimated recoverable petroleum reserves as at 31 December 1987 comprised 5.992 x 106m3 of oil, 18.60 x 106m3 of natural gas liquids, and 111.189 x 109m3 of sales gas. Production from the Jabiru oil accumulation commenced in August 1986 via the Jabiru Venture, a floating production facility. A total of 1.528 x 106m3 of oil had been produced from the Jabiru accumulation up until 31 December 1988. Development of the Challis oil accumulation is currently under consideration via a similar but slightly larger floating production facility. Development of the Petrel and Tern gas accumulations have been the subject of detailed technical assessment but no firm commitment to proceed with development has been made.

  • As at 31 December 1989 the Otway Basin, which is located along the southeast margin of the Australian mainland, was known to contain a total of seven economic and six subeconomic petroleum and non-petroleum gas accumulations. All have been discovered since the late 1950s as a result of petroleum exploration drilling. Three accumulations have been or could be used as a source of petroleum natural gas or carbon dioxide: the North Paaratte gas accumulation in Victoria and the Caroline carbon dioxide accumulation in South Australia, both of which are currently being exploited, and the Wallaby Creek gas accumulation in Victoria, which has been identified by permit holders as an accumulation likely to be developed in the future (1992-1994). In addition, the Katnook and Ladbroke Grove gas accumulations in South Australia are being considered for development in the near future. The initial petroleum reserves of the Otway Basin as at 31 December 1988 are estimated to be 0.483 billion cubic metres of sales gas and 0.002 million kilolitres of condensate (not including the reserves of the Katnook and Ladbroke Grove accumulations). Production from the Caroline carbon dioxide accumulation commenced in 1968, and this field continues to supply this commodity much of the South Australian and Victorian markets. Production of natural gas from the North Paaratte accumulation commenced in August 1986. This field supplies domestic and industrial users in Warrnambool, Victoria.

  • This report summarises technical information on the petroleum and non-petroleum accumulations found in the Browse Basin up to 30 June 1991. The report contains a brief overview of the geology of the Browse Basin and describes the location and significance of all known petroleum accumulations. The nature of the Browse Basin sequence, and the petroleum accumulations found to date, indicate that additional petroleum resources are likely to be discovered. The known petroleum accumulations are a major potential resource and highlight the potential of the basin to satisfy some of the nation's energy and industrial resource requirements in the next century.

  • As at January 1993, nineteen hydrocarbon accumulations, six of which are commercial, have been discovered in the Canning Basin. The commercial accumulations occur in Permian to Devonian reservoirs on an area of relatively shallow basement (Lennard Shelf) flanking the northern margin of the Fitzroy Trough. Oil is produced from Famennian reefs, associated drape structures, and four-way dip closures in Permo-carboniferous, Grant Group and Anderson Formation sandstones. The most likely sources of these hydrocarbons are Late Devonian and Carboniferous marine shales in the Fitzroy Trough kitchen area. The small size of the accumulations in the Canning basin (less than 0.5 million barrels of recoverable oil) precludes the development of large infrastructure projects. Oil is trucked to the storage and shiploading facilities at Broome and then shipped to the Kwinana oil refinery in Western Australia. On the southern margin of the Fitzroy Trough, oil and gas have been recovered from a transgressive Ordovician sequence of sandstones shales and carbonates. Although the Ordovician has yet to yield a commercial discovery, Devonian reef plays in the overlying section may enhance the attractiveness of Ordovician objectives in this area. To date, exploration effort in the basin has been largely directed to the northern, onshore Canning Basin. The offshore Canning and the Kidson Sub-basin remain underexplored. Higher risk plays in these areas have yet to be adequately tested.

  • This report on the Perth Basin, Western Australia, is the tenth in the Australian Petroleum Accumulation Series. The series presents data on Australia's identified petroleum resources, together with an appraisal of their geological setting, hydrocarbon habitat and characteristics. In the case of commercial accumulations, details of their size, development and production history are included. The APA database, on which this series is based, was developed in cooperation with petroleum companies and State and Northern Territory Mines Departments. It is linked to PEDIN, the publicly available petroleum exploration information database maintained jointly by the Bureau of Resource Sciences and the Australian Geological Survey Organisation.