Several factors point to the presence of active petroleum systems in the Bight Basin. Many wells in the region had minor oil and/or gas indications such as fluorescence or cut and significant oil and gas shows were reported from Greenly 1 in the southern Ceduna Sub-basin. Fluid history analysis of samples from the base of Jerboa 1 in the Eyre Sub-basin has revealed the presence of a palaeo-oil accumulation. Analysis of the fluid inclusion oil points to a lacustrine source.

Wells in the Duntroon Sub-basin show clear indications of migration having occurred at several stratigraphic levels. Stranded coastal bitumens of natural origin have been recovered from Australia's southern shorelines for about 100 years. Many of these are asphaltites that are considered to have originated from a Jurassic to Early Cretaceous marine source rock. Recent geochemical and carbon isotopic studies have shown a correlation between the asphaltites, the Albian to Cenomanian Blue Whale supersequence of the Bight Basin and marine oil shales from the Albian Toolebuc Formation of the onshore Eromanga Basin. These results provide further evidence for the presence of at least one marine source rock unit in the region and strengthen the argument that the asphaltites originated in the Bight Basin.

Evidence for hydrocarbon generation in the Ceduna Sub-basin is also provided by the presence of active hydrocarbon seepage. The majority of seepage slicks, interpreted from Synthetic Aperture Radar data, occurs along the margins of the major depocentre, the Ceduna Sub-basin, in areas where significant Late Tertiary to Recent faulting extends to the seafloor or at onlap points of potential reservoir/carrier beds or seals. Hydrocarbon seepage correlates with regional drainage foci and patterns of late stage reactivation faults, which have focused laterally migrating hydrocarbons to produce active, probably episodic seepage at specific locations in the basin. Where these features are absent, seepage may be passive and/or be governed by long distance migration to points of seal failure.

The sequence stratigraphic framework developed by Geoscience Australia has allowed the identification of several potential hydrocarbon source intervals in the basin. These range from Late Jurassic syn-rift lacustrine shales to late Cretaceous marine and deltaic facies. While the Jurassic-early Cretaceous non-marine source intervals are important in the shallower, more proximal parts of the basin, the key to the petroleum prospectivity of the basin probably resides in the Late Cretaceous deltas and associated marine facies. The Cenomanian and Campanian-Maastrichtian deltas built out into a narrow restricted seaway prior to and immediately after the commencement of slow seafloor spreading between Australia and Antarctica in the Late Santonian.

This seaway would have provided an excellent environment for the development of organic-rich rocks. The marine shales of the Albian-Cenomanian Blue Whale Supersequence, the mobile substrate to the Cenomanian growth faults, have proven source rock potential and, on geochemical evidence, have been suggested as the possible source of the asphaltites that are regularly found along the southern margin of Australia. The White Pointer Supersequence contains both marine condensed sections and coaly deposits and has good to excellent source potential for both oil and gas.The preservation potential for organic-rich rocks would have been enhanced in the high accommodation setting of the growth-fault controlled depocentres.

In addition, seismic indications of thick shale-prone intervals within the dominantly marine Tiger Supersequence provide encouragement for the presence of Turonian age source rocks in the basin. The dominantly progradational Hammerhead Supersequence has excellent reservoir potential and there is a high likelihood of regionally extensive marine seal facies within the upper aggradational portion of the succession. The basinward thickening (up to 5000 metres) geometry of the Hammerhead is the key to the loading and maturation of successively younger source rocks. Modelling shows that generation and expulsion commenced from the Turonian onwards.

Finally, the Cenomanian growth faults set up a pattern of upward migration from mature source rocks into shallower reservoirs. These faults, which sole out in the Blue Whale shales, have been reactivated several times and formed the locus for the nucleation of new faults.