南方海相油气地质特征及勘探方向的选择

Marine Oil-Gas Geological Characteristics in South China and Exploration Direction

南方海相中—古生界主要生油层系的分布,受两次大规模海进和频繁的海进海退所控制,两次大规模的构造事件和后期强烈的改造形成了多种圈闭条件。根据层序划分、生储盖配置、主要含油气层,南方纵向上可划分为 Z_2—∈_1、O-3—S_1、D_2—C_1、P_1和 P_2—T_1五个含油气系统;横向划分为八个含油气远景区,即“华北”、中—下扬子、湘中—浙西、黔中北—湘鄂西、川东—滇东、南盘江地区、浙闽粤东部、三江地区。共评价38个地区,其中,上古生界Ⅰ、Ⅱ类地区有19个,下古生界Ⅰ、Ⅱ类地区有8个。勘探选区应“抓两头、占两厢”,即以江南隆起为核心,下古生界有利勘探区为上、下扬子北部和江南隆起北侧;上古生界勘探重点为上、下扬子及江南隆起南北两侧。

The distribution of major Meso-Paleozoic marine source rock in South China is controlled by twice large marine transgressions and frequent transgressions and regressions.Two large scales ot structural events together with later strong reformation made many kinds of traps at pre- sent.Vertically,Z_2-∈_1,O_3-S_1,D_3-C_1,P_,P_2-T_1,five petroleum systems,may be divided in the region based on sequence division, source-reservoir-cap rock assemblage,major oil/gas-bearing beds as well.Laterally,it has eight prospective zones of“Huabei”, Middle-Lower Yangzi,middle of Hunan-west of Jiangxi,middle and north of Guizhou-west of Hunan and Hubei,east of Sichuan-east of Yunnan,Nanpanjiang area,east of Jiangxi and Fujian and Guangdong, Sanjiang area.Up to now,38 areas have been evaluated,19 of them are type Ⅰ or type Ⅱ in Upper Paleozoic,and in Lower Paleozoic,8 of them are type Ⅰ or type Ⅱ.It is considered that the exploration stress should be put on north of Upper and Lower Yangzi,and northern side of Jiangnan Uplift in Lower Paleozoic;and in Upper Paleozoic,put the stress on Upper and Lower Yangzi,and northern and southern sides of Jiangnan Uplift.