华南海相下组合层序地层格架与油气勘探

在建立区域层序地层格架的基础上,指出区域性主力烃源岩及盖层主要形成于超层序的海侵体系域;高品质的区域性储层通常与超层序的高水位期-低水位期相一致。华南下组合海相碳酸盐岩油气纵向上总体存在3套生储盖组合,并将其划分为界面型、低位型、海侵型、高位型和综合型5种类型,不同类型的生储盖组合特征及成藏地质特征存在差异。提出礁滩相灰岩-白云化或白云岩-古岩溶为最有利储层,古隆起-后期构造圈闭为最有利部位,川东南-黔北地区为最有希望尽快取得突破的新区块的认识。

Sequence stratigraphic framework of marine lower assemblage in South China and petroleum exploration

Based on establishment of regional sequence stratigraphic framework,it is believed that the regional main source rocks and cap rocks would have been formed in the transgressive system tract of the supersequence;while the high-quality regional reservoirs would be consistent with the highstand and lowstand of the supersequence.Vertically,3 source-reservoir-cap combinations occur in the lower assemblage(Lower Paleozoic) marine carbonates in South China,and they can be divided into 5 types,including boundary type,lowstand type,transgressive type, highstand type and composite type.Each type of source-reservoir-cap combination has diffe-(rent) features of reservoiring geology.It is suggested that reef flat limestone-dolomitized limestone/dolomite-(palaeokarst) are the most favorable reservoirs,palaeohigh-late structural traps are the most favorable location;and southeastern Sichuan-northern Guizhou area is the frontier where exploration breakthrough would be expected in the near future.