中国南方海相油气勘探前景

对南方海相构造-层序-油气系统的综合研究表明,南方海相地层发育5套区域性主力烃源岩和多套局域性烃源岩(下寒武统、下志留统、中二叠统、上二叠统、下三叠统),烃源岩热演化程度的不均一性决定了南方下古生界以天然气勘探为主,上古生界为油气勘探兼顾.印支及其以后的改造运动对南方海相及中新生代盆地的含油气性控制起到主要作用,叠合盆地中、晚期形成的油气系统最具勘探潜力.原生及次生油气藏的分布主要受生烃有利相带和古隆起、古斜坡的控制.环扬子陆块叠合盆地群、苏北-南黄海南部盆地以及江南隆起北缘冲断推覆体下海相地层保存区将是南方海相油气勘探的重点.

Petroleum prospect of marine sequences in South China

The comprehensive study of tectonics-sequence stratigraphy-petroleum system showed that five sets of major regional and some local source rocks developed in the tectonic evolution of South China, including the Lower Cambrian and Lower Silurian in Caledonian cycle, Middle Permian and Upper Permian in Hercynian cycle, and Lower Triassic in Indo-Sinian cycle. Due to inhomogeneous maturity of source rocks in this area, gas exploration would focuse on the Lower Paleozoic, and oil and gas exploration would be in the Upper Paleozoic. The reformation from Indo-Sinian cycle to Hymalayan cycle controlled hydrocarbon accumulation in the Mesozoic-Cenozoic basin and marine sequences in the southern China. The petroleum systems formed in the medium-late period of the superimposed basins should have the most potential of hydrocarbon exploration. The primary and secondary oil-gas pools mainly distributed along the sedimentary facies favorable for hydrocarbon generation, and these oil-gas pools were controlled by the ancient uplift and slope. The comprehensive evaluation concluded that the important areas for petroleum exploration in marine sequences of the southern China will be in the superimposed basins along the margin of Yangtze landmass, Subei-southern South Yellow Sea Basin and the marine sequences preserved under the over-thrust nappe along the northern margin of Jiangnan uplift.