上下扬子构造演化及叠合盆地油气地质条件对比

中国南方海相油气勘探是当前油气勘探的热点领域,并已显示出巨大的勘探潜力。在系统研究扬子块体构造旋回演化及沉积发育的基础上,以地质类比为手段,剖析了上、下扬子区宏观地质特征的异同,认为上、下扬子区叠合盆地演化具有"早期统一、晚期分异"的特征,主要控制因素是扬子块体与周缘构造单元的相互作用,分异的界限大致是以印支运动为界。通过油气地质条件的分析,认为上、下扬子区典型叠合盆地成藏要素存在时空关系上的可类比性,并与构造旋回具有良好的耦合性,在此基础上,重点分析了四川盆地油气勘探对南黄海盆地勘探的指示意义,认为中、古生界海相地层是南黄海油气突破的潜力区,深层油气勘探需重点关注,以及古隆起对油气聚集的关键作用。

COMPARATIVE STUDY OF TECTONIC EVOLUTION AND PETROLEUM GEOLOGICAL CONDITIONS OF TYPICAL SUPERIMPOSED BASINS IN UPPER AND LOWER YANGTZE BLOCK

The Yangtze region in south China bears great oil potential and is now one of the important sites for petroleum exploration in marine sediments in China. Upon the basis of tectonic evolution and deposition in the Yangtze block, this paper is devoted to the comparative study of the similarities and differences of macro-geological features between the Upper and Lower Yangtzes. The results suggest that the tectonic evolution of the superimposed basins in the upper and lower Yangtze blocks is similar in Paleo-Mesozoic, but different in Meso-Cenozoic. the time boundary of differentiation is about Indosinian and the controlling factors is the interaction among the Yangtze block and adjacent tectonic units. Hydrocarbon accumulation conditions are controlled by basin tectonic evolution and have good coupling pattern with tectonic cycles. The experiences learnt from the Sichuan basin are of great significance to the oil and gas exploration in the South Yellow Sea basin. Upon the fact it is concluded that the Paleo-Mesozoic marine strata is a potential area for break-through of oil and gas exploration in the South Yellow Sea basin. More attention should be paid to the deep strata, and paleo-uplifts are prosperous exploration targets in superimposed basins.