Influence of sulfate on the generation of bitumen components from kerogen decomposition during catagenesis  

作　　者：Jia Wu Wen Qi Fu-Jie Jiang Qing-Yong Luo Chun-Lin Zhang Huan-Zhen Hu Zi Wang Qi-Sheng Ma Yong-Chun Tang 

机构地区：[1]State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(Beijing),Beijing,102249,China [2]College of Geoscience,China University of Petroleum(Beijing),Beijing,102249,China [3]PetroChina Research Institute of Petroleum Exploration&DevelopmentdNorthwest,Lanzhou,Gansu,730020,China [4]PetroChina Research Institute of Petroleum Exploration&Development,Beijing,100083,China [5]University of Southern California,Los Angeles,CA,90089,USA [6]Power Environmental Energy Research Institute,Covina,CA,91722,USA

出　　处：《Petroleum Science》2021年第6期1611-1618,共8页石油科学（英文版）

基　　金：supported by National Natural Science Foundation of China (No. 41403049);the Foundation of State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum (Beijing) (No. PRP/indep-3-1715);National Science and Technology Major Project during the 13th Five-Year Plan Period (2016ZX05007-002)。

摘　　要：High-quality source rocks in saline lacustrine or marine sedimentary environments often show early peak petroleum generation and enhanced hydrocarbon yields,which have conventionally been attributed to organosulfur-enhanced thermal decomposition of kero gen.However,there is increasing awareness that the coexisting inorganic salts,particularly sulfates,might also contribute to the acceleration of petroleum generation.In this study,we investigated the influence of sulfates on the thermal decomposition of kerogen sampled from the Pingliang Formation in the Ordos Basin.Our results demonstrate that the kerogen samples mixed with sulfate generate more hydrocarbons with a lower peak production temperature than their sulfate-free counterparts.Detailed chemical analysis revealed that the presence of sulfates significantly facilitated the generation of resins and asphaltenes at temperatures below 350℃,corresponding in our simulations to the early stage of petroleum generation(Easy%R_o <1.0%).We hypothesize that sulfates can promote the fragmentation of kerogen via direct thermochemical oxidation into a complex mixture of bitumen components that consist mostly of compounds typically encountered in the classical resin and asphaltene fractions.The findings reveal a new reaction paradigm between sulfates and organic macromolecules that could offer useful guidance in the exploration for low-maturity oils.

关 键 词：SULFATE KEROGEN Thermal decomposition Resins and asphaltenes Redox reactions 

分 类 号：O611.65[理学—无机化学] P618.13[理学—化学]