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: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=611910
• 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：非传统燃料的发展是否以温室效应为代价？非常规能源的支持者经常将减少温室气体排放作为燃料(特别是天然气)的优势。然而，最近备受瞩目的研究表明，由于地上基础设施的泄漏，开采和加工地点是甲烷的大量排放者。或者，从油井里。所有非常规井都具有钻井密集型的特点，井被认为是完井(固井)期间和之后的常见故障点，甚至在废弃之后都被认为是常见的故障点，有人担心井的故障可能会严重影响现场的整体排放。特别是，人们对发生气体运移(GM)的井感到担忧，即气体沿着井筒向上流动，沿着水泥与地层接触处的水泥缺陷流向地面。多达30%的油井可能会通过转基因泄漏，泄漏速度高达200立方米的甲烷。众所周知，一些油井允许GM从超过1000米深的含气地层中开采。令人惊讶的是，转基因对场地总排放量的贡献尚不清楚，部分原因是受监管的转基因测试不衡量排放率。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，检测方法也太粗糙了，无法识别出中度到重度病例。这些粗略的测试大体上塑造了我们对转基因的理解，而我们对这个问题的地球化学和运输因素的理解也相对粗略。人们对以下方面知之甚少：转基因在地表的表达模式(地表扰动的足迹、对称性、运输路径、地球化学)；不同类型井或土壤的可变性；天然甲烷生产与检测(或产生假阳性)的混淆程度；或转基因对整个场地排放的贡献。这项拟议的研究对这些问题进行了研究。解决这个泄漏问题很重要，因为甲烷的温室潜力是二氧化碳的20倍，而非常规物质的广泛发展可能会显著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的井场以及萨斯喀彻温省的一个活跃的非常规井场进行。最初两年的研究将包括调查以确定转基因并了解其发病率。在接下来的几年里，这项研究涉及对转基因油井的深入研究，建立健全的转基因会计做法，最后建立转基因累计排放量的估计，以与我的小组记录的已知全场排放足迹进行比较。能源公司不太可能赞助这项研究，但他们会容忍现场完成这项研究，只要有建设性合作记录的值得信赖的研究人员以自筹资金的方式开展工作。我的团队在这方面处于有利地位。HQP在这个项目中有很强的作用，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。这项工作将建立与环境影响相关的重要知识和对大气中转基因累计排放量的估计，并将为学生项目带来重大的科学挑战。这个项目产生社会影响的可能性很大。这一结果可能会改变非传统燃料的发展进程，可能会影响监管制度，并可能促使人们在能源行业、在转基因或其他泄漏来源上为转基因寻求新的技术解决方案。