Pre-competitive work helps reduce petroleum exploration risk in the Bight
The Minister for Industry, the Hon. Ian Macfarlane MP, recently awarded three 2012 offshore petroleum exploration permits in the Bight Basin to three major international petroleum explorers.
The release of exploration acreage in the Bight Basin, first in 2009 and later in 2012, was based on pre-competitive work undertaken by Geoscience Australia, the results of which attracted a great deal of industry interest.
A key component of Geoscience Australia's pre-competitive work program in the Bight Basin, undertaken between 2006 and 2009 as part of the New Petroleum and Offshore Energy Security programs, was a survey designed to search for hydrocarbon source rocks in the canyons of the continental shelf.
Geoscience Australia Senior Geologist, Jennie Totterdell, said uncertainty concerning the presence of source rocks in the basin had previously been considered a major exploration risk, as good source rocks had not been intersected by any exploration wells.
In 2007 a marine survey using the RV Southern Surveyor acquired high resolution swath bathymetry data and then used this data to plan dredge sites for targeted rock samples exposed in the walls of submarine canyons in nine areas of interest. This resulted in the sampling of a rich, oil-prone marine source rock of Cenomanian-Turonian boundary age on the western up-dip margin of the Ceduna Sub-basin."The acquisition of samples showing that excellent potential source rocks are present in the basin went a long way towards addressing that key exploration risk and changed perceptions of prospectivity in this frontier region," Jennie Totterdell added.
The permit areas are situated in the central Great Australian Bight, off southern Australia, and are located mostly within the frontier Ceduna Sub-basin, in the eastern part of the Bight Basin. The exploration permits were awarded to Murphy Australia Oil Pty Ltd and Santos Offshore Pty Ltd (EPP43) and Chevron Australia New Ventures Pty Ltd (EPP44 and EPP45).
The guaranteed work programs of geological and geophysical studies offered for the three permits is valued at $580 million over the next three years. When combined with BP's 3-year $600 million work program for four permits awarded in 2011, this brings the total guaranteed minimum exploration investment across all permits in the Bight Basin to $1.2 billion.
Geoscience Australia provides scientific and technical support to the Department of Industry for the annual release of the Offshore Petroleum Exploration Areas which in turn supports promotion of the petroleum prospectivity of Australia.