loadingSedimentary and geochemical characteristics of
the Triassic Chang 7 Member shale in the Southeastern Ordos Basin, Central China
Jing-Wei Cui;Ru-Kai Zhu;Zhong Luo;Sen Li
【期刊名称】《石油科学（英文版）》 【年(卷),期】2019(016)002
【摘要】The Ordos Basin is the largest petroliferous basin in China,where the Chang 7 Member shale serves as the major source rock in the basin,with an area of more than 100,000 km2.So far,sedimentary and geochemical characterizations have rarely been conducted on the shale in shallow (＜ 1000 m) areas in the southeastern part of the basin,but such characterizations can help identify the genesis of organic-rich shale and promote the prediction and recovery of shale oil.In this paper,several outcrop sections of the Chang 7 Member in the Tongchuan area were observed and sampled,and sedimentary and geochemical characterizations were conducted for the well-outcropped YSC section.The study results show that the Chang 7 Member shale is widely distributed laterally with variable thickness.The organic-rich shale is 7-25 m thick in total and exhibits obvious horizontal variation in mineral composition.In the eastern sections,the shale contains organic matter of Type Ⅱ2-Ⅲ and is low in thermal maturity,with high clay mineral content,low K-feldspar content,and no pyrite.In the western