Eromanga Basin

The Eromanga Basin in New South Wales runs along the Queensland border from South Australia to about longitude 147E where easterly thickening of sediments across the Cunnamulla Shelf / Nebine Ridge marks a transition into the Surat Basin. The sediments of the Eromanga Basin represent the shallower shelf areas of the main basin, located in Queensland and South Australia.

Exploration Potential and new Accumulations

The pre-Mesozoic fill of the troughs beneath the Eromanga Basin is considered to be mainly Devonian aged, although possibilities for Permian-fill have been identified. The basement deeps may also contain thickened Mesozoic strata, and excellent porosities and permeabilities in the Hooray Sandstone indicate the existence of reservoir rocks in the Mesozoic section. Geochemical analysis of the artesian waters attests to the presence of hydrocarbons in regionally extensive aquifers in the Eromanga Basin.

Recognition of the troughs provides new possibilities for the presence of thickened sections containing mature source rocks adequate for local hydrocarbon generation. A possibility highlighted by wet gases in the artesian waters of the basin. Identification and delineation of basin deeps beneath the Eromanga Basin is essential to formulating a regional framework and to understanding basin geometry and structural evolution in New South Wales.

Exploration Potential and New Accumulations

In addition to Gilmore and Log Creek discoveries hydrocarbons have been recorded in Quilberry, Yongala, Leopardwood and Bodalla wells. Several studies have identified potential new petroleum reef reservoirs within the Bury Limestone and the Cooladdi Dolomite. Current gas discoveries, coupled with numerous oil shows strongly indicate the future discovery potential within the Adavale basin.