This report summarises the results of the 1990 SAGASCO Resources Ltd consultancy project for Santos Ltd on the Triassic Nappamerri Group in South Australia. The Nappamerri Group has significant exploration potential in areas where faults act to connect deeper mature early Permian source rocks to reservoirs within this succession. In the absence of such conduits the Nappamerri Group appears to be unprospective. Sixteen areas of fair to good Nappamerri Group prospectivity are recognised in the South Australian sector of the Cooper Basin. Of these at least five have the potential to provide near-term drilling targets. The northern Patchawarra Trough area around Wimma and Cuttapirrie has the best overall perceived prospectivity, as this is where reservoir, seal, source and migration factors appear to be optimal. Potential prospects in the area are related to faulting and stratigraphic trapping mechanisms. The area has many of the prospectivity factors associated with proven discoveries along the GMI Trend and Lake Hope Block. The western margin of the Patchawarra Trough is an area of significant stratigraphic uncertainty, and is not a short term target. But the area could have significant stratigraphic trapping potential. There is evidence for wrench movement at the end of Nappamerri Group deposition. Wrench faults may have provided migration pathways for hydrocarbons into the western flank of the area. Six major play types have been recognised. These are: · Crestal Plays · Low Side Fault Plays · Wrench Fault - Related Plays · Regional Truncation Plays · Onlap Plays · Updip, Porosity Pinch-out Plays The Nappamerri Group was deposited in a regime of increasing yet episodic tectonic instability, accentuated on the major highs. The final tectonic event resulted in major northward tilting of the basin, accompanied by probable right-lateral movement along the Cooper Wrench Zone. This event ended Cooper Basin deposition. The Nappamerri Group subdivisions established by Channon and Wood (1990) for the northern Patchawarra Trough have been extended to most of the South Australian Cooper Basin. Although only the four units established by Channon and Wood (1990) have been mapped, at least six regional sedimentary packages are discernible. In addition to the primary work of stratigraphic subdivision of the Nappamerri Group and documentation of potential play types, emphasis has been given to defining mature source rock areas underlying the Nappamerri, identifying primary migration conduits and potential migration routes, and describing feasible models of faulting which impact on prospectivity. Recommendations for future work include pointers to specific tasks within the realms of prospect mapping, source rock evaluation, palynological studies, drill core analyses, seismic studies and stratigraphic mapping.