阿拉斯加北坡区域地质演化及油气资源

在收集国内外资料的基础上,分析研究阿拉斯加北坡地区的构造演化过程,地层序列及演化阶段,并对本区石油勘探历史,地质特征和油气资源进行了总结。确定了4个主要地层序列,分别为富兰克林层序(密西西比系之下),埃尔斯米尔层序(密西西比系—三叠系),波弗特层序(侏罗系—下白垩统)和布鲁克斯层序(下白垩统—第四系)。阿拉斯加北坡地区经历了比较复杂的演化过程,北坡盆地即位于此。盆地主要经历了3个演化阶段,分别为埃尔斯米尔造山阶段、同裂谷阶段和前陆阶段。本区具有石油远景的岩石大多在密西西比纪及之后的地层中,它们记录了整个被动大陆边缘、裂谷和前陆盆地构造阶段地层序列和地质方面的演化。本区油气潜力巨大,勘探历史悠久。石油和天然气的未探明储量分别为244.9×108桶和2.905×1012m3,页岩油约9.4×108桶,页岩气约1.19×1012m3。

GEOLOGICAL EVOLUTION AND HYDROCARBON RESOURCES POTENTIAL IN NORTH SLOPE, ALASKA

Based on the collected data and materials, we analyze the evolution of tectonic and stratigraphy in the North Slope of Alaska and conclude the history of exploration, geological features and the hydrocarbon resources. Four major sequences are described here which are Franklinian sequence (older than Mississippian), Ellesmerian sequence (Mississippian to Triassic), Beaufortian sequence (Jurassic to Lower Cretaceous) and Brookian sequence (Lower Cretaceous to Quaternary) respectively. The North Slope of Alaska has gone complicated history of evolution where The North Slope basin evolved here. The basin has experienced three major evolutions which are Ellesmerian orogeny, rift and foreland basin tectonic stage. The North Slope has a large petroleum potential and has gone through a long exploration history. Petroleum prospective rocks in the province, are mostly Mississippian and younger, recording a sequential geological evolution through passive margin, rift and foreland basin tectonic stage. The main mean of undiscovered resources include 24.3 billion barrels of oil, 102.6 trillion cubic feet of gas, 0.94 billion barrels of shale oil and 42 trillion cubic feet of shale gas.