Key Laboratory of Petroleum Resources, Gansu Province/Key Laboratory of Petroleum Resources Research, Institute of Geology and Geophysics/The Analytical Service center, Research Center of Oil and Gas Resources, Northwest Institute of Eco-environment and Resources, CAS, Lanzhou, 730000, PR China.
PetroChina Qinhai Oilfield Research Institute of Exploration & Development, Dunhuang, 736202, PR China.
Sci Rep. 2018 Apr 26;8(1):6568. doi: 10.1038/s41598-018-25051-1.
This organic-rich shale was analyzed to determine the type, origin, maturity and depositional environment of the organic matter and to evaluate the hydrocarbon generation potential of the shale. This study is based on geochemical (total carbon content, Rock-Eval pyrolysis and the molecular composition of hydrocarbons) and whole-rock petrographic (maceral composition) analyses. The petrographic analyses show that the shale penetrated by the Chaiye 2 well contains large amounts of vitrinite and sapropelinite and that the organic matter within these rocks is type III and highly mature. The geochemical analyses show that these rocks are characterized by high total organic carbon contents and that the organic matter is derived from a mix of terrestrial and marine sources and highly mature. These geochemical characteristics are consistent with the results of the petrographic analyses. The large amounts of organic matter in the Carboniferous shale succession penetrated by the Chaiye 2 well may be due to good preservation under hypersaline lacustrine and anoxic marine conditions. Consequently, the studied shale possesses very good hydrocarbon generation potential because of the presence of large amounts of highly mature type III organic matter.
对这套富含有机质的页岩进行了分析，以确定有机质的类型、来源、成熟度和沉积环境，并评估页岩的生烃潜力。本研究基于地球化学（总碳含量、岩石热解和烃类的分子组成）和全岩岩相学（岩相组成）分析。岩相学分析表明，柴页 2 井所钻遇的页岩中含有大量的镜质体和腐泥质体，这些岩石中的有机质为Ⅲ型且高度成熟。地球化学分析表明，这些岩石具有较高的总有机碳含量，且有机质来源于陆地和海洋的混合源且高度成熟。这些地球化学特征与岩相学分析的结果一致。柴页 2 井钻遇的石炭系页岩序列中大量的有机质可能是由于在高盐度湖泊和缺氧海洋条件下得到了很好的保存。因此，由于存在大量高度成熟的Ⅲ型有机质，研究区页岩具有非常好的生烃潜力。
