徐淮地区二叠系烃源岩地球化学特征及页岩气资源潜力——以宿州3-1钻井剖面为例

Geochemical characteristics and shale gas resource potential of Permian source rocks in Xuhuai area: A case study of the 3-1 drilling section of Suzhou

徐淮地区在构造上属于南华北板块,拥有华东最重要的煤炭基地徐州煤田、淮北煤田与淮南煤田,二叠系煤系烃源岩普遍发育,但针对该地区二叠系页岩气形成的地质条件的研究成果少见。通过对宿州3-1钻孔二叠系山西组、下石盒子组和上石盒子组泥页岩进行系统采样,开展了有机质丰度、类型和成熟度等地球化学分析测试,揭示该地区二叠系有效的富有机质泥页岩层段发育在山西组和下石盒子组,有机碳含量较高,山西组优于下石盒子组;有机质主要为Ⅲ型干酪根,处于成熟至高成熟阶段,具有较高的生烃潜力。

Xuhuai area,part of southern North China Block,is bestowed with important coal bases in East China,such as the Xuzhou coalfield,Huaibei and Huainan coalfields. The coal measure source rocks generally develop in Permian,but the study on the geological conditions of the formation of Permian shale gas in this area is basically blank. This paper systematically sampled the mud shale of the Permian Shanxi Formation and the Lower and Upper Shihezi formations and carried out a geochemical test analysis of organic material abundance,type and maturity. It is revealed that the effective organic-rich mud shale sections in the Permian system develop in the Shanxi Formation and the Lower Shihezi Formation,which are all high in the abundance of organic carbon and the former is superior to the latter. The organic matters are matured or even highly matured,kerogen of type III,a great potential for hydrocarbon generation.