澳大利亚北卡那封盆地油气地质特征及勘探潜力分析

北卡那封盆地是澳大利亚最主要的产油气盆地,也是世界上主要的富气盆地之一。盆地经历了裂前、早期裂谷、晚期裂谷和裂后被动大陆边缘发育阶段,充填了以中生界占绝对优势的厚约15 km的沉积层系。三叠系—下白垩统内发育了4套烃源岩,油气主要储于上三叠统、上侏罗统和下白垩统。区域上,石油绝大部分分布于巴罗—丹皮尔次盆地,而滦金台地和埃克斯茅斯高地则富集了大部分的天然气和凝析油。截至2004年底,盆地内已发现石油(包括凝析油)5.27×108t,天然气28 424×108m3。油气地质综合分析表明该盆地仍具有良好的勘探前景,勘探程度中等的埃克斯茅斯高地、埃克斯茅斯次盆地和比格尔次盆地的勘探潜力最大。 

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.