EAPSI: Assessing Microbial Activity in the Shale and Implications for Natural Gas Extraction

近年来，通过水力压裂从页岩中开采天然气的做法在全球范围内有所增加。水力压裂是油井钻井的一种改进版本，旨在从地下储集层中提取气体而不是流体。水力压裂产生数百万升受污染的废液，很难以经济和环保的方式处理。这些液体的处理是一个巨大的公共卫生问题。废液中污染物的来源还不清楚，也不清楚在废液和页岩中保持生物活性的微生物的作用。这项研究将调查页岩上微生物细胞的活跃程度以及它们利用的碳源类型，包括这些来源是否可以来自页岩本身。这项研究将与日本海洋地球科学技术厅的地下微生物群落专家稻崎文雄和莫罗诺博士合作进行，该机构将提供进入一流生物地球化学实验室的通道。这项研究将对页岩水力压裂过程中发生的生物地球化学过程有更好的了解，并将导致改进废液处理和水力压裂方法，以减少环境污染。地下有机化合物因微生物活动而分解，可能会导致重金属等有毒元素的共同释放。这项研究将确定哪些与钻井液和马塞卢斯页岩有关的有机化合物在生物上是可用的。纳米二次离子质谱仪(NanoSIMS)将用于追踪稳定同位素标记的有机化合物被来自废液的微生物细胞同化的情况，以及附着在页岩上的细胞是否可以利用页岩中的天然有机化合物。NanoSIMS分析确定了细胞同化某种稳定的同位素标记或页岩来源的碳源的百分比。该NSF EAPSI奖是与日本科学促进会合作资助的。

Extracting natural gas from shales by hydrofracturing has increased globally in recent years. Hydrofracturing is a modified version of oil well drilling that is designed for extraction gases rather than fluids from a subsurface reservoir. Hydrofracturing produces millions of liters of contaminated waste fluid that is difficult to dispose of in an economical and environmentally-friendly manner. Treatment of these fluids is a great public health concern. The origin of contaminants in waste fluids is not well understood nor is the role of microorganisms that can remain biologically active in the fluids and shales. This research will investigate the degree to which microbial cells present on shales are active and the types of carbon sources that they utilize including whether these sources can come from the shale itself. The research will be conducted in collaboration with Drs. Fumio Inagaki and Yuki Morono, experts on subsurface microbial communities, at the Japan Agency for Marine-Earth Science and Technology which will provide access to a premier biogeochemistry laboratory. This research will develop a better understanding of biogeochemical processes occurring during shale hydrofracturing and should lead to improved waste fluid treatment and hydrofracturing methods to reduce environmental contamination. The breakdown of organic compounds in the subsurface by microbiological activity can result in the co-release of toxic elements such as heavy metals. This research will determine what organic compounds associated with drilling fluids and Marcellus shale are biologically available. Nano secondary ion mass spectrometry (NanoSIMS) will be used to trace the assimilation of stable isotope-labeled organic compounds into microbial cells derived from waste fluids as well as whether cells attached to shale can utilize native organic compounds in the shale. NanoSIMS analysis determines the percentage of cells that assimilate a certain stable isotope-labeled or shale-derived carbon source. This NSF EAPSI award is funded in collaboration with the Japan Society for the Promotion of Science.