Two separate and distinct sedimentary basins are currently being explored in the Bass Straits off the southeast coast of Australia. These are both Tertiary basins, although older Sediments are present. The Gippsland Basin contains up to 15,000 feet of Sediments with some 8,000 feet of Tertiary. The Bass Basin has a Tertiary fill of about 7,000 feet, overlying older sediments. By the end of March, 1966, four offshore wells in the Gippsland Basin had resulted in two commercial gas-condensate fields. Light oil was also encountered in the second discovery. One dry wildcat in the Bass Basin found a favorable section of marine Tertiary Strata.
Deux bassins sédimentaires, distincts et séparés, sont en cours d'exploration dans de Détroit de Bass côte sud-est de l'Australie. Il s'agit de deux bassins tertiaires, quoique des sédiments plus anciens existent aussi. Le Bassin de Gippsland contient jusqu'à 4,500 mètres de sédiments, dont environ 2,400 mètres de tertiaire. Le Bassin de Bass possède un tertiaire d'environ 2,000 mètres reposant SUT des sédiments plus anciens.
A la fin de mars 1966 quatre puits forés au large des côtes, dans le Bassin de Gippsland, avaient découvert deux champs de gaz à condensat commercial. Du pétrole léger a été trouvé lors de la seconde découverte.
Un puits d'exploration sec a recoupé une section favorable de niveaux marins tertiaires.
The occasional presence of heavy oil, washed up along the beaches of southeast Australia, drew early attention to this region and at least 100 onshore exploration wells have been drilled, dating back to 1924.
In spite of numerous oil and gas shows, no commercial production was encountered. It was not until exploration moved offshore that success was had.
The purpose of this paper is to present a brief case history of petroleum exploration in the Gippsland and Bass basins off the southeast Australian coast and to summarize results to date in geological terms, particularly as they relate to the occurrence of oil and gas.
It is a narrative report on exploration developments in this offshore region from inception to September, 1966.
This offshore exploration history has been divided into two chapters covering the periods of March, 1960 to December, 1964 when the first wildcat was spudded, and January, 1964 to the date of this paper. by W. E. WALLIS Standard Oil Company, N.J., U.S.A.
EXPLORATION MARCH, 1960 DECEMBER, 1964 TO In 1960 and 1961, based on recommendations by Lewis G. Weeks, Haematite (an affiliate of Broken Hill Proprietary, Ltd.) acquired 39.8 million acres of offshore leases; virtually all the continental shelf of southeastern Australia and northern Tasmania. Haematite then covered these leases with an airborne magnetometer survey and seismic reconnaissance. Previously, the Bureau of Mineral Resources conducted magneto-
