Molecular Organic Geochemical Characteristics and Coal Gas Potential Evaluation of Mesozoic Coal Seams in the Western Great Khingan Mountains

作     者：QU Yue SHAN Xuanlong DU Tiantian DU XianLi ZHAO Rongsheng QU Yue;SHAN Xuanlong;DU Tiantian;DU Xianli;ZHAO Rongsheng

作者机构：College of Earth SciencesJilin UniversityChangchun 130061China Key Laboratory for Evolution of Past Life and Environment in Northeast AsiaJilin UniversityMinistry of EducationChangchun 130061China College of Mining EngineeringHeilongjiang University of Science&TechnologyHarbin 150022China 

出 版 物：《Acta Geologica Sinica(English Edition)》 (地质学报（英文版）)

年 卷 期：2020年第94卷第2期

页      面：409-417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] 08[工学] 0818[工学-地质资源与地质工程] 0708[理学-地球物理学] 0816[工学-测绘科学与技术] 

基　　金：the National Natural Science Foundation of China(Grant No.41430322) The anonymous journal reviewers and editors are acknowledged for their valuable comments. 

主　　题：coal source rocks molecular organic matter geochemical characteristics low-maturity gas coal gas western part of the Great Khingan Mountains 

摘      要：Coal-bearing strata are widespread in the western Great Khingan Mountains. Abundant coal resources have been found in the Jurassic Alatanheli Groups, the Cretaceous Bayanhua Groups, the Damoguaihe Formation and the Yimin Formation. The organic geochemical characteristics were analyzed in combination with hydrocarbon source rock evaluation and molecular organic geochemistry experiments, and the coal gas potential of coal seams was evaluated. The source rock evaluation results indicated that the Mesozoic coal samples have the characteristics of high organic matter abundance(TOC30%), low maturity(Ro values of approximately 0.6%), and type Ⅲ composition. The hydrocarbon generation potentials of the Alatanheli Groups and Bayanhua Groups are high, while the generation potentials of the Damoguaihe Formation and the Yimin Formation are low. The results of geochemistry show that the depositional environment of the coal seam was a lacustrine, oxidizing environment with a low salinity, and the source of the organic matter was mainly higher plants. Affected by weak degradation, the coal seams mainly formed low-maturity gas of thermal catalytic origin. The Cretaceous coal seams contain a large amount of phytoplankton groups deposited in a low-stability environment affected by a transgression event, and the potential range varied widely. For the Jurassic coal seams, the depositional environment was more stable, and the coal seams feature a higher coal-forming gas potential.