Addressing the problem of methane release from unconventional energy sites

解决非常规能源场所的甲烷释放问题

• 批准号: RGPIN-2014-05894
• 负责人: Risk, David
• 金额: $ 2.7万
• 依托单位: St. Francis Xavier University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=567456
• 关键词: Addressing; problem; methane; release; unconventional

This research addresses a critical societal question of our time: Does unconventional fuel development come at a greenhouse cost? Proponents of unconventionals frequently cite the reduced greenhouse footprint of the fuels as an advantage (gas in particular). However, recent high profile studies have shown that extraction and processing sites are heavy emitters of methane, due to leaks from aboveground infrastructure. Or, from wells. All unconventionals share the characteristic of being drilling-intensive, and wells are thought to be common failure points both during and after completion (cementing), and even after abandonment, and there is some concern that well failures may contribute heavily to overall site emissions. In particular, there is concern around wells that develop Gas Migration (GM), where gases flow up the well bore, along cement imperfections at the contact between cement and formation, to the surface. Up to 30% of wells may leak via GM, at rates as high as 200 cubic meters of methane. Some wells are known to allow GM from gas-bearing formations over 1000 m deep. Surprisingly, the contribution of GM to overall site emissions is unknown, in part because regulated GM tests do not measure release rate. Many provinces do not require GM testing of any sort, and even if they did, the testing methods are too coarse to identify anything less than moderate to severe cases. These coarse tests have generally shaped our understanding of GM, and our understanding about the geochemical and transport elements of this problem is proportionately coarse. Too little is known about: the pattern of GM expression at the surface (footprint of disturbance at surface, symmetry, transport pathways, geochemistry); the variability across different types of wells or soils; the degree to which natural methane production confounds detection (or creates false positives); or the fractional contribution of GM to overall site emissions. The proposed research takes on these questions. Addressing this leakage problem is important, as methane’s greenhouse potential is 20 times that of CO2, and widespread development of unconventionals could significantly increase overall human methane emissions. This research will be done at abandoned and suspended well sites in Nova Scotia, and an active unconventional site in Saskatchewan. The initial two years of research will involve surveys to identify GM and understand its incidence. In subsequent years, the research involves in-depth study of wells with GM, establishment of sound accounting GM practices, and lastly building estimates of cumulative GM emissions to compare against known whole-site emission footprints recorded by my group. It is unlikely that energy companies will sponsor this research, but they will tolerate it being done onsite, so long as trusted researchers with an established track record of constructive collaboration are doing the work in a self-funded manner. My group is positioned well in this regard. There is a strong role for HQP in this project, and good possibilities for expansion of the research and HQP footprint via collaborations, which could expand its conceptual scope and/or geographic coverage. This work will build important knowledge related to environmental impacts and estimates of cumulative GM emission to the atmosphere, and will incorporate significant scientific challenge for student projects. The likelihood of societal impact from this project is strong. The results could alter the course of unconventional fuels development, could impact regulatory regimes, and could spur a pursuit of new technological solutions to GM in the energy industry, on GM or other leakage sources.

这项研究解决了我们这个时代的一个关键社会问题：非常规燃料的开发是否以温室效应为代价？非常规燃料的支持者经常将燃料（特别是天然气）减少温室足迹作为一个优势。然而，最近引人注目的研究表明，由于地上基础设施的泄漏，开采和加工场地是甲烷的重排放源。或者，来自威尔斯。所有非常规井都具有钻井密集型的特点，威尔斯井被认为是完井（固井）期间和之后，甚至是废弃之后的常见故障点，人们担心，井故障可能会严重影响现场的总体排放。特别是，在发生气体迁移（GM）的威尔斯井周围存在问题，其中气体沿井筒向上流动，沿着水泥与地层之间接触处的水泥缺陷流动到地面。多达30%的威尔斯井可能通过GM泄漏，泄漏率高达200立方米甲烷。已知一些威尔斯井允许GM从超过1000米深的含气地层中开采。令人惊讶的是，转基因对整个场地排放的贡献是未知的，部分原因是受管制的转基因测试不测量释放率。许多省份不要求进行任何形式的转基因检测，即使他们这样做了，检测方法也太粗糙，无法识别任何低于中度到重度的病例。这些粗糙的测试基本上形成了我们对GM的理解，而我们对这个问题的地球化学和输运元素的理解也相对粗糙。我们对以下方面知之甚少：转基因在地表的表达模式（地表干扰的足迹、对称性、传输路径、地球化学）;不同类型的威尔斯井或土壤之间的变异性;天然甲烷生产对检测的干扰程度（或产生假阳性）;或转基因对整个场地排放的贡献率。拟议的研究涉及这些问题。解决这一泄漏问题很重要，因为甲烷的温室效应是二氧化碳的20倍，而非常规能源的广泛开发可能会大大增加人类甲烷的总排放量。这项研究将在新斯科舍省的废弃和暂停井点以及萨斯喀彻温省的一个活跃的非常规地点进行。最初两年的研究将包括调查，以确定转基因和了解其发病率。在随后的几年里，研究涉及深入研究的威尔斯井与通用汽车，建立健全的会计通用汽车的做法，最后建立估计的累积通用汽车的排放量，以比较已知的整个网站的排放足迹记录由我的小组。能源公司不太可能赞助这项研究，但他们会容忍它在现场完成，只要值得信赖的研究人员具有建设性合作的良好记录，以自筹资金的方式进行这项工作。我的团队在这方面做得很好。HQP在该项目中发挥着重要作用，并且通过合作扩大研究和HQP足迹的可能性很大，这可能会扩大其概念范围和/或地理覆盖范围。这项工作将建立有关环境影响和估计累积转基因排放到大气中的重要知识，并将纳入学生项目的重大科学挑战。该项目产生社会影响的可能性很大。研究结果可能会改变非常规燃料的发展进程，可能会影响监管制度，并可能促使人们寻求新的技术解决方案，以解决能源行业中的转基因问题、转基因问题或其他泄漏源问题。