Abstract:

Australia's North West ich in oil and gas resources，particularly gas，and is one of the key bases for supplying LNG in the world.The shelf not only has the highest petroleum exploration potential in Australia, but it is also one of the important regions targeted by Chinese oil companies for expanding international petroleum exploration and production. Based on data collected from various sources,this paper discusses the oil and  gas  distribution  patterns， documents the factors controlling such disrtibutions and optimizes the favorable exploration areas.Regionally,the discovered oil and gas reserves are largely confined to the North Carnarvon Basin.Stratigraphically,they are mostly reservoired in clastic reservoirs in the Upper Triassic,Jurassic or Lower Cretaceous，which are sealed by the extensive Lower Cretaceous mudstones and shales.  The distribution is characterized by patterns of oil in the inner fairway and gas in the outer fairway，gas in the lower reservoirs and oil in the upper reservoirs，and dominance of gas over oil.  Oil fields mainly occur in sub-basins，which were developed during Jurassic rifting and contain effective oil source rocks.  The humic kerogen type and high maturity of source rocks determine that the petroleum resources are dominated by gas in the North West Shelf. The Jurassic rift controlled the areal distribution of oil.  On basis of integrated studies of petroleum geology and discovery process of oil and gas fields，this study selected 7 favorable exploration areas:Exmouth Plateau，Exmouth Sub-basin，Barcoo Sub-basin，Caswell Subbasin，Sahul Platform，Calder Graben and Vulcan Sub-basin.

Key words: North West Shelf, oil and gas distribution, main control factor, favorable exploration area