PETROLEUM GEOLOGICAL FEATURES AND EXPLORATION POTENTIAL ANALYSES OF NORTH CARNAVON BASIN, AUSTRALIA

The North Carnarvon Basin is the premier oil and gas producing basin in Australia and one of the world-class gas-rich basins.It experienced pre-rifting,early rifting,late rifting,and post-rifting passive margin development stages.The basin was filled with about 15 km thick sediments,which are overwhelmingly dominated by the Mesozoic.Four sets of source rocks were developed in the Triassic-Lower Cretaceous succession.Oil,condensate and gas are mainly reservoired in the Upper Triassic,Upper Jurassic and Lower Cretaceous.Regionally,oil is mostly distributed in the Barrow and Dampier Sub-basins whereas the Exmouth Plateau and Rankin Platform contain bulk of the condensate and gas.By the end of 2004,5.27×10⁸ tonnes of oil and 28 424×10⁸ m³ of gas had been discovered in the basin.Integrated petroleum geological analyses indicate that the basin has a considerable hydrocarbon prospectivity.The moderately explored Exmouth Plateau,Exmouth Sub-basin and Beagle Sub-basin comprise the most promising areas with the best exploration potential.