中扬子区与上、下扬子区油气地质条件的对比分析

COMPARATIVE PETROLEUM GEOLOGICAL STUDY BETWEEN MIDDLE YANGTZE AREA AND UPPER AND LOWER YANGTZE AREAS

陈焕疆 邱之俊

Chen Huanjiang Qiu Zhijun

同济大学 2. 地质矿产部, 中南石油地质局

Tongji University 2. Central-South China Bureau of Petroleum Geology, Ministry of Geology and Mineral Resources

中扬子区在震旦纪—志留纪期间,其总体构造格局是南接南华地槽,北邻秦岭地槽,由于南北各有一个被动大陆边缘,有利于油气的生成、运移和聚集。泥盆纪至中三叠世为一套地台型沉积,亦具有形成油气的良好地质条件。本区晚元古代至古生代的沉积、构造特点近于上扬子区,但较上扬子区活跃;而中新生代近于下扬子区,较下扬子区活动强度要弱一些。中扬子区这种"动、静相宜"的大地构造特征,为油气的生成、运移和聚集提供了良好的环境。

The character of lower architexture of Middle Yangtze Area is similar to that of Upper Yangtze Area while the upper architexture is similar to that of Lower Yangtze Area.In fact,it is a polysuperposed basin consisting of an Upper Triassic-Upper Jurassic basin,a Lower and Middle Triassic-Upper Paleozoic basin,and a Sinian-Silurian basin.Generally speaking,the petroleum richness in such a poly-superposed basin would be much higher than that in a simple basin.The petroleum prospects of deep objectives may be concluded as.1.oil/gas accumulation in Indosinian unconformity,2.oil/gas accumulation in basement rocks and ancient buried hills,and 3.oil/gas accumulation controlled by overthrusts.However,the sedimentation and tectonic movement from Proterozoic to Paleozoic in Middle Yangtze area are more active than those in Upper Yangtze Area while Mesozoic sedimentation and tectonic movements are relatively less active than those in Lower Yangtze Area.Such characteristics provide an unique favourable condition for generation,migration and accumulation of oil/gas in Middle Yangtze Area.

https://doi.org/10.11781/sysydz198804305