UNS: Collaborative Research: Measurement and Modeling of the Pathways of Potential Fugitive Methane Emissions During Hydrofracking

由于钻井和水力压裂技术的进步，在过去的十年里，美国深层页岩地层的天然气产量显著增加。2010年，页岩气占美国干天然气年供应量的23%，预计到2035年这一比例将增加到48%。页岩气开发具有巨大的经济优势，包括依赖国内生产，因为美国天然气储量丰富，而且与燃烧天然气和煤炭相比，使用天然气可以改善空气质量。该项目将通过对包括水力压裂开采和生产过程在内的温室气体足迹的生命周期分析，研究生产井中未控制的逸散性排放。美国页岩气资源的开发预计将在未来20年稳步增长，然而，这些活动向大气释放的逸散甲烷的数量和机制存在很大的不确定性。来自不同水力压裂地点的甲烷测量值差异很大，这表明逸散性排放在很大程度上是可以预防的，这取决于钻井和钻井运营商的做法。该项目将在水力压裂作业之前和过程中提供一套急需的、及时的基线和逸散甲烷排放测量数据，从而量化和确定钻井和天然气开采作业过程中不同环节释放的甲烷排放源。这将填补一个关键的知识空白，为制定有效的管理策略和操作实践提供信息，以最大限度地减少甲烷排放，提高天然气的整体温室气体效益。该项目将：(1)通过收集连续的景观尺度甲烷通量测量，量化水力压裂期间的基线和逸散甲烷排放；(2)通过测量甲烷中13C同位素的连续大气通量，确定甲烷排放的生物和地质来源；(3)利用足迹模型和先进的大涡模拟，将测量到的甲烷通量划分为水力压裂过程的不同组成部分，以隔离空间和时间上的通量源。该项目将利用与俄亥俄州立大学页岩能源与环境现场实验室（SEEL）的持续合作，该实验室将提供钻井作业的现场访问，并通过SEEL与钻井和井运营商的合作伙伴关系提供有关管理实践和作业时间表的信息。pi将与俄亥俄州立大学（OSU）推广办公室合作，为公众开发在线和印刷资源和论坛，描述页岩气开发对当地和区域空气和水质的影响。他们还将与俄勒冈州立大学扩展部合作，将该项目的成果传递给水力压裂从业者，他们可以使用有关钻井平台管理实践的信息来有效减少逸散性甲烷排放。这两家公司将与西弗吉尼亚大学（West Virginia University）和Extension公司分享已开发的产品，并在页岩气开发问题上进行广泛合作。此外，他们将利用与俄亥俄州水资源中心现有的外展关系，在与俄亥俄州水管理协会组织的水午餐会上介绍与该项目有关的工作，并在州机构代表的单独研讨会上介绍。在本项目中，将对一名研究生进行甲烷通量观测和建模方法的培训。该项目还将培训达特茅斯女性科学项目的本科生进行实地考察和数据分析，并根据该研究撰写荣誉论文。

1508994(Bohrer) & 1509297(Matthes)Production of natural gas from deep subsurface shale formations in the US has increased considerably in the last decade due to the advancement in drilling and hydraulic fracturing technology. In 2010, shale gas accounted for 23% of annual dry natural gas supply in the US, with projections that this capacity will increase to 48% by 2035. There are large economic advantages of shale gas development, including reliance on domestic production due to the abundance of natural gas in the US and the improved air quality when using natural gas compared with the combustion of gas and coal. This project will examine fugitive emissions, those not controlled in the production well, in a life cycle analyses of the greenhouse gas footprint that include the hydrofracking extraction and production processes.The development of shale gas resources in the United States is predicted to grow steadily over the next twenty years, however there is large uncertainty surrounding the quantity and mechanisms of fugitive methane emissions released to the atmosphere from these activities. The large range among methane measurements from different hydrofracking sites suggests that fugitive emissions may be largely preventable and are dependent on the practices of the drill and well operators. This project will provide a much needed and timely set of baseline and fugitive methane emission measurements before and during hydrofracking operations that will quantify and identify the sources of methane emissions released during different components of the drilling and gas extraction operations process. This will fill a critical knowledge gap that will inform the development of effective management strategies and operations practices to minimize methane emissions and improve the overall greenhouse gas benefits of natural gas. This project will: (1) Quantify baseline and fugitive methane emissions during hydrofracking by collecting continuous landscape-scale methane flux measurements; (2) Identify biological and geological sources of methane emissions by measuring continuous atmospheric fluxes of 13C isotopes in methane; (3) Attribute measured methane fluxes to different components of the hydrofracking process by using a footprint model and advanced large eddy simulations to isolate flux sources in space and time. This project will leverage ongoing collaboration with the Ohio State University Shale Energy and Environment Field Laboratory (SEEL), which will provide the site access to drilling operations and information about the management practices and operations timeline will be provided through the SEEL partnership with the drill and well operators. The PIs will partner with the Ohio State University (OSU) Extension Office to develop online and print resources and forums for the general public describing the effects of shale gas development on local and regional air and water quality. They will also work with OSU Extension to transfer results from this project to hydrofracking practitioners who could use information regarding drill pad management practices to effectively reduce fugitive methane emissions. The PIs will share the developed products with West Virginia University and Extension, with whom they extensively collaborate on shale gas development issues. Furthermore, they will leverage existing outreach relationships with the Ohio Water Resources Center to present the work related to this project at a water luncheon organized with the Water Management Association of Ohio, and at a separate seminar to state agency representatives. A graduate student will be trained in observation and modeling methods for methane fluxes during this project. This project will also train undergraduate students from the Dartmouth Women in Science Program in fieldwork and data analyses to develop honors theses from this research.