There has been a continuing upsurge of exploration activity in Australia since 1976, leading to a record expenditure in 1981. Although large economic discoveries have been rare, significant discoveries have been made at widely separated localities, particularly in the unproductive Eromanga and Canning basins. At the same time, geochemical analyses and organic microscopy determinations of material from wells drilled have helped to identify Australia's potential source rocks and their maturity for petroleum generation. The additional drilling and seismic surveying have also enabled a better definition and understanding of reservoir distribution, development of traps, and thermal and tectonic history of a number of Australia's sedimentary basins.

It has been assessed that there is an 80% chance of finding more than 950 million bbl of oil, but only a 20% chance of finding more than 3,800 million bbl of oil. However, the reliability of these numbers is questionable, because it has been necessary to use a large amount of subjective judgment in the assessment.

According to the assessment, the best chances for future oil discoveries are offshore in certain Western Australian basins and onshore in the Eromanga and Canning basins. Undiscovered gas resources are believed to have a somewhat different distribution.

End_of_Article - Last_Page 967------------