河北省宽城区中上元古界页岩气源—储特征分析

Analysis of the source-reservoir characteristics of the middle-upper proterozoic shale gas in Kuancheng District

河北省宽城区洪水庄组和下马岭组是一套古老的海相页岩,为了研究两组暗色泥岩有机地化和储层矿物学特征,在宽城县和承德县分别实施了2口浅层钻探井,并对采集的样品进行了X射线衍射、扫描电镜、压汞实验等分析。测试结果显示,2套地层显微组分以Ⅱ1为主,总有机碳含量较高,成熟度较高,是该区页岩气的主要烃源岩。矿物组成中洪水庄组和下马岭组脆性矿物含量都很高,主要以石英为主,黏土矿物中以高岭石占绝对优势;特低孔渗物性特征和良好的含气性表现都是该区页岩气成藏提供了重要的物质基础。

Hongshuizhuang and the Xiamaling Formation in Kuancheng District,Hebei Province are a set of ancient marine shale.In order to study the organic geochemical and reservoir mineralogical characteristics of the two groups of dark mudstones,two shallow formations were implemented in Kuancheng County and Chengde County respectively,with analysis of the collected samples by X-ray diffraction,scanning electron microscopy,and mercury intrusion experiments.The test results showed that the two sets of formations were mainly composed ofⅡ1,with high total organic carbon content and high maturity.They were the main source rocks of shale gas in this area.In the mineral composition,the content of brittle minerals in the Hongshuizhuang Formation and the Xiamaling Formation was very high,mainly quartz,and kaolinite was the dominant clay mineral;the characteristics of ultra-low porosity and good gas-bearing performance were both shale gas accumulation in this area,the result provided an important material basis.