May 2008 MONTHLY MEETING

DATE: Wednesday 21st May 2008

VENUE: Rugby Club, Level 3, Rugby Place (near Pitt & Alfred St) Sydney

TIME: 5.30pm for 6:00pm

Technical Meeting

Results of Recent Data Acquisition in Onshore and Offshore Frontier Basins

Mr Edward Bowen, Geoscience Australia)

Abstract: Geoscience Australia (GA) recently embarked on a wide-ranging data acquisition program, funded by the Australian Government’s ‘Energy Security Program’. The onshore component involves the assessment of the petroleum, uranium, thorium and geothermal potential of the continent, while the offshore program is designed to provide pre-competitive data and interpretive material to stimulate petroleum exploration in under-explored regions of the continental margin.

In the Remote Eastern Frontier region, 6,000 km of seismic, gravity and magnetic data was acquired in early 2007 over the Capel and Faust basins, where results from earlier research cruises and satellite gravity maps suggested the presence of sedimentary depocentres. In late 2007, a marine reconnaissance survey acquired detailed magnetics, gravity, multibeam sonar and sub-bottom profiler data, along with seafloor sampling to better define the major depocentres.

Along the Southern Margin, from Albany to Tasmania, the results of previous work are being synthesised to better understand the tectonic development of the margin since break-up from Antarctica, improve stratigraphic knowledge and produce 2D petroleum system models. This follows recovery of dredge samples from a canyon on the edge of the Ceduna Terrace with high TOC values that clearly indicates the presence of an excellent source rock in the Bight Basin. In addition, GA and the Geological Surveys of Victoria and Tasmania are funding the acquisition of 70,000 km of high resolution aeromagnetic data in the Bass Basin, together with a further 70,000 km of data along the west coast of Tasmania, between Cape Otway and Port Davey.

On the Southwest Margin, between Margaret River and Carnarvon, a seismic survey later this year in the Mentelle Basin, the outboard parts of the Perth Basin and the southern Carnarvon Basin will collect 6,000 km of industry standard 2D seismic data using an 8 km solid streamer. This new data, together with over 7,000 km of re-processed seismic, will enable an assessment to be made of the petroleum potential of areas beyond the existing oil-producing field at Cliff Head. These data will be complemented by a marine reconnaissance survey, collecting gravity, magnetic and swath data, to enable better resolution of basin depocentres and provide the opportunity to dredge samples of strata that crop out in submarine canyons.

Within the Producing Regions (primarily NW Shelf and Gippsland), petroleum systems modelling studies, on a whole-of-basin scale, will form part of Geoscience Australia’s ongoing core program. Aeromagnetic surveys have been flown in the offshore Canning Basin (45,000 line km) and aeromagnetic acquisition is continuing over parts of the onshore Canning and Kidson sub-basin to complement existing datasets.

Biography

Edward Bowen graduated from Macquarie University in 1970 with Honours in geophysics and structural geology. As a Geophysicist, and later Chief Geophysicist for Amax Exploration he worked on a wide range of mineral exploration projects throughout Australia, the South Pacific and South-east Asia. Subsequently, he joined Robertson Research as Chief Geophysicist and worked extensively on World Bank funded assessments of the petroleum potential of basins in Papua New Guinea and the Philippines. Later he was invited to join the staff at Macquarie University where he held an Associate Professor’s position for 6 years.

Recently he returned from an extended circumnavigation of the world and accepted the offer of a position in the Petroleum Prospectivity and Promotions Group of Geoscience Australia. Currently, he leads the Southwest Margin Project which will be undertaking major seismic acquisition, seismic re-processing and marine reconnaissance surveys during the next year.

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For additional information, please phone (9024 8805) or email Gua Bin.