Publication Name: The Cooper & Eromanga Basins Australia
Authors: T. Scholefield
Date Published: June 1989
Number of Pages: 25
Reference Type: Book Section
Abstract:
Two areas with the potential to contain economic accumulations of hydrocarbons are recognised in thenorthern Eromanga Basin region. In the east and south, on the crest of the Maneroo Platform, an
overbank/backswamp depositional environment for the Birkhead Formation can be demonstrated. Here the
Birkhead Formation, considered to be the likely source of oil shows recorded in Newlands-1 and oil recovered in
Corona-l, has good to very good source potential and demonstrated maturity. To the west, the Birkhead
Formation thins and becomes silty with a corresponding decrease in source potential and maturity.
From sparse data, some hydrocarbon potential is demonstrated within sediments of the 'basal Jurassic'. These sediments reach considerable thickness within the lovelle Depression and around its southern margin and elsewhere are only present in deeper areas of the Maneroo Platform. Although the non-coal generative potential of the 'basal Jurassic' is inferior to that of the Birkhead Formation, maturity of any sediments deposited on the crest of the platform is inferred to be comparable. Shows recorded in the 'basal Jurassic' may indicate that early mature oil is accumulating in this zone in some areas.
Within the lovelle Depression, the Permian Aramac Coal Measures are mature with good to excellent source potential and are within the peak oil generation window at Ayrshire-1, where an oil show was recorded. Maturity
is comparable to the maturity of older Carboniferous and Devonian rocks thought to have sourced the oil recovered from Lake Galilee-1 in the Koburra Trough. The Aramac Coal Measures could potentially source hydrocarbons which may have migrated into younger Permian sediments and Eromanga Basin reservoirs on the flanks of the lovelle Depression.
Several Eromanga Basin reservoirs (Adori and Hutton Sandstone) are of good quality. The Hutton Sandstone is
extensive to the north and west, pinching out onto the flanks of residual basement highs to the east. The Adori
Sandstone is well developed to the east but pinches out, or is eroded, to the north-west around Cork-1.