Petroleum Exploration Licence 50 in northern South Australia covers approximately 9714 square km of the prospective Eromanga Basin, in which over 400 million barrels of oil in place have been discovered since 1977. To date, only 3 exploratory wells have been drilled in the area now held as PEL 50 by Felstea Pty Ltd. Although these wells were unsuccessful, they demonstrated the presence of hydrocarbon shows, reservoirs, seals and mature source rocks. Around 2300 line km of mostly recent vintage seismic data are available for the area, which define three drillable prospects, three strong leads, and another 24 leads showing roll-over on one or two seismic profiles. Additionally, good potential exists for stratigraphic traps on the flanks of the seismically defined structures. The currently mapped structural prospects and leads in PEL 50, if filled to spill, were formerly conservatively estimated by Santos Ltd to have the potential to contain over 200 million barrels of recoverable oil. Oil exploration targets in PEL 50 are primarily 800-1220 feet thick Jurassic fluvial sandstone reservoirs, likely sourced by underlying Jurassic lacustrine shales and by adjacent downdip Permo-Triassic coal-rich source beds. Regional seal is provided by an Early Cretaceous marine transgressive shale. Structuring has occurred principally in the Early Tertiary, prior to oil generation and migration. To the east, near the centre of the Eromanga Basin, comparable anticlinal structures with reservoirs of similar age and depositional environment have produced at DST rates of up to 4600 BOPD and have individual field reserves of up to 42MMBO recoverable. Depth to economic basement is less than 5000 feet on structural highs. Dry hole cost is estimated to be about US$500,000; to drill and complete is expected to cost about US$900,000. The primary target Late Jurassic Namur Sandstone is anticipated at a depth of about 3600 feet on structure, and to have between 150-450 feet of vertical closure. With over 20% porosity plus good to excellent permeability, the Namur is a high quality reservoir. Within PEL 50, cored Middle Jurassic Birkhead Formation source rocks have yield total organic carbon values of up to 15.2%, and appear to be mature for oil generation. Shows were recorded in two wells drilled previously, while 125 km north of PEL 50, Poolowanna 1 produced 96 BOPD. The mapped structural traps within PEL 50 overlie prominent rejuvenated basement tectonic features, which on seismic exhibit sediment onlaps and evidence of subsequent compression; these are draped by the overlying Mesozoic reservoirs. The drillable prospects at Lake Promise, Lake Kool and Lakeside encompass mapped areas of closure of between 4000 and 15,000 acres, with estimated recoverable reserves of between 13 and 46 million barrels of oil. There is a minimum commitment to drill 2 wells and perform additional seismic or drilling during the first 5-year tenure period ending June 1996.