Publication Name: Eastern Australian Basins Symposium 2001
Authors: B.H. Michaelsen and D.M. McKirdy
Date Published: November 2001
Number of Pages: 35
Reference Type: Magazine Article
Abstract:The aromatic hydrocarbon contents of 62 terrestrially-derived oils from the Cooper and Eromanga Basins in South Australia and Queensland have been screened using whole-oil GC-MS. An earlier study (McKirdy et a!. 1997) had revealed the existence of at least two distinct families of Permian (Cooper Basin) oils, which in turn could be distinguished from oils of Jurassic/Cretaceous (intra-Eromanga) origin. A novel combination of aromatic hydrocarbon source and maturity parameters based on methyl phenanthrene isomers has now enabled the recognition of multiple petroleum systems; instances of migration from Permian kitchens into Jurassic reservoirs; and Eromanga traps which have received charges from both Permian and Jurassic/Cretaceous source rocks. A cross-plot of 1-methylphenanthrene /9-methylphenanthrene versus 2-methylphenanthrene/1-methylphenanthrene allows for a semiquantitative estimate of the relative contributions of Cooper and romanga-sourced hydrocarbons to the Jurassic and Cretaceous reservoirs of the Eromanga Basin. Several expulsion events are also identified.