中、下扬子区构造演化与海相地层成藏主控因素分析

On the Structural Evolution and Major Control Factors of Reservoir Formation in Marine Strata in the Middle and Lower Yangtze Region

通过构造演化特征分析了海相烃源岩的发育,中、下扬子区中-古生代经历了加里东和海西-早印支旋回两个阶段的海相被动大陆边缘和克拉通盆地演化,形成了岩性稳定的巨厚中-古生界,发育了6套烃源岩,具有较强的生烃能力。烃源岩的高演化和6期构造运动使古油藏遭受破坏。从分析高演化海相地层的烃源类型、构造演化以及整体封存等成藏条件,认为中、下扬子地区在强烈的构造运动背景下,烃源岩的“再次”补给能力和区域保存条件将成为控制中、下扬子地区油气富集的主要因素。

On the basis of analysis on the characteristics of structural evolution, the growth of the source rocks is analyzed. In the period of Mesozoic-Palaeozoic, Caledonian events and the evolution of Hercynian-early Indo-Chinese cycle are experienced in two-phase marine passive continental margin and Craton basin in the lower and middle Yangtze Region, by which stable enormous thick Mesozoic-Palaeozoic deposites are induced, six sets of source rocks are produced, it has a strong capacity of hydrocarbon generation. The ancient oil reservoirs are almost completely destroyed by high evolution source rocks and structural movements. By analyzing reserve forming conditions of high evolution marine strata, including types of hydrocarbon source, the structural evolution, the condition of preservation and so on, it is considered that under the background of intensive structural movements, the “second”compensatory capabilities of the hydrocarbon source in the middle and lower Yangtze Region and regional preservation conditions would be the major factors to control the enriched oil and gas collection in this region.