中国东部中、新生代含油气盆地火成岩油气藏成藏机制

Formation Mechanism of Hydrocarbon Reservoirs Related to Igneous Rocks in Mesozoic-Cenozoic Basin, Eastern China

中国东部中、新生代盆地油气资源丰富,其地层中广泛发育着以玄武质及粗面质为主的火成岩。这些火成岩既可为油气提供储集空间也可作为油气藏的盖层,形成了一定量与火山岩及潜火山岩相关的油气藏。与火山岩有关的油气藏主要有火山岩储层型、火山岩盖层型和风化壳型,而与潜火山岩有关的油气藏主要有拱张裂缝型、隐爆角砾岩型、原生裂缝型、蚀变破碎型和侧向隔挡型。本文评述了这些火成岩型油气藏的成藏机制,提出了中国东部中、新生代含油气盆地中的火成岩油气藏综合成藏模型,以期这类油气藏在今后的油气勘探工作中得到充分重视。

There are a number of petroleum-producing Mesozoic-Cenozoic basins in the coastal areas of eastern China.Voluminous volcanic and sub-volcanic intrusive rocks, dominantly basaltic and trachytic in composition, are intercalated in sedimentary sequences. These igneous rocks serve as caprocks as well as reservoir beds. Oil and gas reservoirs related to volcanic rocks can be classified into the volcanite-trapping type, volcanite-sealing type and weathered crust type, and those related to sub-volcanic intrusions include the doming-derived fracture type,crypto-explosive breccia type, primary fracture type, alteration-fractured zone type, lateral sealing type,contact metamorphic zone type and lateral sealing type. A generalized model for the formation of hydrocarbon reservoirs related to igneous rocks is proposed. More attention should be paid to igneous-related reservoirs during exploration for hydrocarbons in these basins in the future.