The petrological characteristics and signif icance of organic-rich shale in the Chang 7 member of the Yanchang Formation,south margin of the Ordos basin,central China

作     者：Sen Li Ru-Kai Zhu Jing-Wei Cui Zhong Luo Jing-Gang Cui Han Liu Wei-Qiang Li 

作者机构：Research Institute of Petroleum Exploration and DevelopmentBeijing 100083China Tight Oil and Gas Research Center of National EnergyBeijing 100083China Key Lab of Oil and Gas Reservoir of PetroChinaBeijing 100083China 

出 版 物：《Petroleum Science》 (石油科学（英文版）)

年 卷 期：2019年第16卷第6期

页      面：1255-1269页

核心收录：

学科分类：081803[工学-地质工程] 0709[理学-地质学] 0819[工学-矿业工程] 0808[工学-电气工程] 08[工学] 0820[工学-石油与天然气工程] 0707[理学-海洋科学] 0817[工学-化学工程与技术] 0818[工学-地质资源与地质工程] 0708[理学-地球物理学] 0807[工学-动力工程及工程热物理] 0815[工学-水利工程] 0816[工学-测绘科学与技术] 0827[工学-核科学与技术] 0813[工学-建筑学] 0703[理学-化学] 0814[工学-土木工程] 0825[工学-航空宇航科学与技术] 0704[理学-天文学] 

主　　题：Organic-rich shale Volcanic ash Framboidal pyrite pseudocrystal Chang 7 member Ordos basin 

摘      要：The organic-rich shale of the Chang 7 member is the most important source rock in the Ordos basin.The sedimentary environment and the controlling factors of organic matter enrichment,however,are still in contention.In this investigation,the Yishicun outcrop,located on the south margin of the Ordos basin,has been considered for the study.X-ray diffraction,polarizing microscopy,field emission scanning electron microscopy and cathodoluminescence(CL)were used to investigate the petrological features of the organic-rich shale.The content of volcanic ash and the diameter of pyrite framboid pseudocrystals were measured to illustrate the relationship between oxygen level,ash content and the enrichment of organic matter.It has been found that the diameter of pyrite framboid pseudocrystals has a strong correlation with the total organic carbon,demonstrating that the redox status degree of the water column has a positive impact on the enrichment of organic matter.Additionally,with an increase in the ash content,the content of organic matter increased at first and then decreased,and reached a maximum when the ash content was about 6%,illustrating that the ash input has a double effect on the enrichment of organic matter.