全球深层油气藏及其分布规律

深层油气勘探对老油气区（田）扩大储量、稳定产量具有重要意义。以全球深层油气藏的最新资料为基础，系统统计分析了全球深层油气分布特征。在全球（不包括美国本土48州）349个含油气盆地中，87个盆地内发现了深层油气藏。全球深层油气储量的63.3%分布于碎屑岩储集层，35.0%储于碳酸盐岩，其余的1.7%储于岩浆岩和变质岩。构造圈闭富集了全球深层油气储量的73.7%，是深层油气最重要的圈闭类型。被动陆缘盆地和前陆盆地是深层油气最富集的盆地类型，其深层油气储量分别占全球总量的47.7%和46.4%。层系上，深层油气主要富集于5套储集层系：古近系（占全球总量的22.3%）、上古生界（22.2%）、白垩系（18.3%）、新近系（12.8%）和侏罗系（12.8%），深层油气的层系分布特征与中、浅层油气类似。岩盐导致的盐下沉积物的负热异常效应抑制了盆地深层烃源岩的热演化或液态烃向气态烃转化，因此含盐盆地深层油气勘探特别值得关注。建议深层油气勘探应立足于中、浅层已有重大油气发现的地区，特别是发育有一定规模盐岩的地区。

Characteristics and distribution patterns of deep petroleum accumulations in the world

Exploration for deep petroleum accumulations(DPAs)is of great significance to reserve growth and production stabilization of established petroleum provinces(fields).With an update database for the worldwide DPAs,this study attempts to document their distribution characteristics.Among the 349 petroliferous basins in the world(excluding US Lower 48 States),87 basins have discovered DPAs.Clastic rocks and carbonates host 63.3% and 35.0% of the total proved plus probable(2P)deep petroleum reserves in the world,respectively.The remaining 1.7% are in igneous and metamorphic rocks.In terms of trap type,73.7% of the total are entrapped in structural traps.Passive margin and foreland basins contain the bulk of the total 2P deep petroleum reserves,with the former accounting for 47.7% of the total and the latter 46.4%.Stratigraphically,the 2P deep petroleum reserves are largely stored in five reservoir intervals:the Paleogene(hosting 22.3% of the total),Upper Paleozoic(22.2%),Cretaceous(18.3%),Neogene(12.8%) and Jurassic(12.8%).Such a stratigraphic distribution is similar to that of shallow-intermediate reservoirs.As salts have a cooling effect for the subsalt sediments,the maturation of sub-salt source rocks or the conversion of trapped oil to gas can be retarded or delayed.Salt-bearing deep basins deserve special attention for deep petroleum exploration.This study suggests that deep petroleum exploration should target the play fairways where major discoveries have been made in the shallow-intermediate reservoirs,particularly those fairways with salts of certain scale.