Environmental conditions and mechanisms restricting microbial methanogenesis in the Miquan region of the southern Junggar Basin, NW China

作者：Haijiao Fu, Yueguo Li, Xianbo Su, Detian Yan, Shuguang Yang, Gang Wang, Xiaoming Wang, Weizhong Zhao · 发表于：Geological Society of America Bulletin · 年份：2022 · DOI：10.1130/b36272.1 · 被引用次数：20 · 研究领域：Methane Hydrates and Related Phenomena、Hydrocarbon exploration and reservoir analysis、Coal Properties and Utilization

Abstract Early microbial gas has been sealed in reservoirs in the Miquan region of NW China, with little or no supply of current microbial gas. To date, the environmental conditions and mechanisms restricting microbial methanogenesis are still unclear in the Miquan region. Thus, in this study, a series of gas and water samples from coalbed methane (CBM) exploitation wells and in situ coal samples were collected and analyzed to determine the potential for current microbial gas generation, the methanogenic pathways, the source of nutrients, the influence of the environmental conditions on in situ microbial communities and their methanogenesis, and the mechanisms restricting microbial methanogenesis. The gas-production simulation experiments revealed that the existing microbes in the coalbed water were less efficient at converting coal into methane under the approximate in situ conditions, which further verified that there was little or no supply of current microbial gas. The stable isotope compositions of the gas samples suggested that carbon dioxide (CO2) reduction was the dominant metabolic pathway for generating CBM, whereas the methanogenic communities contained a mixture of acetoclastic and methylotrophic methanogens in local areas. The nutrients available for the microbes mainly included the total dissolved nitrogen (TDN) and total dissolved carbon (TDOC), and the in situ dissolution of the coals was a significant source of the TDN, whereas the TDOC was mainly supplied by...