Seismic evidence for seal and reservoir in the Late Cretaceous Ceduna Delta, Great Australian Bight

Summary

The Ceduna Sub-Basin contains a large and underexplored Jurassic - Cretaceous rift, located within the Great Australian Bight Basin. Limited exploration to date has targeted the Late Cretaceous Hammerhead and Tiger Super sequences (SS) of the Ceduna Delta with no as yet, commercial success. The two key wells Potoroo-1 and Gnarlyknots-1A do not penetrate the older Lower Tiger and White Pointer SS within the basin proper and questions remain regarding the presence of effective reservoir and seals.

This study utilises uncalibrated seismic data to investigate the presence of potential reservoir and sealing lithologies within this untested deeper section. Supporting data examples come from ~20,500 km² of recently acquired datasets of the Ceduna 3D and Springboard 3D marine seismic surveys and key wells (Figure 1). Geophysical analysis of seismic attributes including spectral decomposition were used to interpret geomorphology and character of various seismic facies. This allowed interpretation of depositional environments related to deep water, shallow marine and coastal plain settings within a regional context.

Seismic evidence is presented from recently acquired 3D seismic data that supports the interpretation of potential reservoir and sealing lithologies over multiple age strata within the Late Cretaceous Ceduna Delta.

• Ceduna Delta
• White-Pointer
• Tiger
• seismic attributes
• spectral decomposition
• Great Australian Bight