改造型盆地含油气系统分析——以雪峰山西侧盆山过渡带为例

An analysis of the oil and gas system in the reformed basin: a case study of the basin-mountain transitional area on the western side of the Xuefeng Mountain

南方是中国海相碳酸盐岩的主要分布地区之一,发育厚8000～10000m的震旦系—下三叠统海相沉积,形成了以震旦系、寒武系、奥陶系、志留系为主体的海相含油气系统下组合和以泥盆系、石炭系、二叠系、中下三叠统为主体的海相含油气系统上组合。上述含油气层系和油气组合在雪峰山西侧地区也有不同程度的发育,并具有复杂的圈闭条件、保存条件和成藏演化过程,蕴藏着丰富的油气资源。笔者着重讨论了改造型含油气盆地的研究思路、方法及研究区油气系统的地质作用过程,并在此基础上对4个重点区的含油气系统进行了分析,以期为深入开展雪峰山西侧地区油气地质调查和勘探目标区优选提供依据。

South China has Sinian-Lower Triassic marine sediments 8000~10000m in thickness and hence has been considered to be one of the main distribution areas of marine carbonate sediments. There are two assemblages of marine petroleum system： one is the lower assemblage consisting mainly of Sinian, Cambrian, Ordovician and Silurian strata, and the other is the upper assemblage comprising primarily Devonian, Carboniferous, Permian and Middle-lower Triassic strata. The western side of the Xuefeng Mountain has developed various degrees of oil and gas bearing layers and petroliferous assemblages. This area also possesses very rich oil and gas resources characterized by complicated trap and preservation conditions as well as oil reservoir evolution processes. Based on a discussion on the methods for studying the reformed petroliferous basin and geological process of the petroleum system, this paper emphatically analyzed the petroleum system in four key hydrocarbon-bearing areas so as to provide the evidence for petroleum survey on the western side of the Xuefeng Mountain as well as for the optimization of the exploration target areas.