Plug & abandon strategies for Canada's oil & gas wells

在过去10-20年里，随着公众对石油和天然气行业日益严格的审查，该行业、监管机构和各级政府的注意力正转向解决困扰该行业的严重环境管理问题。其中最重要的是长期安全废弃油气井的问题。截至2013年，加拿大已钻探超过55万口油气井，其中大部分位于加拿大西部沉积盆地。仅在艾伯塔省，就有35%的油井被废弃：这一数字加起来约为该省15.1万口废弃油井。目前的油井库存大多有30-40年或更长的历史。加拿大正在进入一个P&A时代，在可预见的未来，每年将有1000口S井被废弃。长期井眼密封需要正确放置密封材料(水泥)，避免污染/混合，并确保水泥与周围岩石的良好粘结。这个为期4年的项目是关于P&A业务的工程设计。该项目有两个关键目标。首先，我们将在更全球化的背景下评估加拿大典型的P&A业务、良好的架构和监管实践的状况。我们将对科学和工程文献进行详细审查，因为它与寿命/密封有关，澄清知识差距并揭露技术问题。其次，通过加拿大研究人员的协作网络和有针对性的互补性子项目，我们将为涉及流体机械问题(放置、清洁、混合以及潜在粘合)的监管和运营决策提供物理和工程基础。我们的团队将进行7项互补和相互关联的研究，以弥补P&A知识差距，同时利用实验、分析和计算方法的组合，结合与行业合作伙伴的实地调查工作，提供根本性的进展。

With the increasing public scrutiny of the oil and gas industry in the past 10-20 years, the attention of theindustry, regulatory authorities and all levels of government is driven towards tackling serious questions ofenvironmental stewardship that afflict the industry. High amongst the list is the question of safe long-termabandonment of oil and gas wells. By 2013, more than 550,000 oil & gas well had been drilled in Canada, mostof which were in the Western Canada Sedimentary Basin. In Alberta alone, 35% of total wells are abandoned:this number adds up to around 151,000 abandoned wellbores in the province. Much of the current well stock is30-40 years old or more. Canada is entering an era of P&A (Plug and Abandonment) in which 1000's of wellswill be abandoned annually for the foreseeable future. Environmental & public safety concerns abound.Long term sealing of wellbores requires proper placement of sealing materials (cement), avoidance ofcontamination/mixing and ensuring a good bond of the cement to the surrounding rock. This 4-year project isabout the engineering design of P&A operations. The project has 2 key objectives. First we will assess thestatus of typical Canadian P&A operations, well architectures and regulatory practices, within a more globalcontext. We will conduct a detailed review of the scientific and engineering literature as it pertains tolongevity/sealing, clarify knowledge gaps and expose technological issues. Second, through a network ofcollaborative Canadian researchers and targeted complementary sub-projects we will provide physical andengineering rationale for regulatory and operational decisions that concern fluid mechanical issues (placement,cleaning, mixing, and thus potential bonding). Our team will conduct 7 complementary and interlinked studiesaddressing P&A knowledge gaps while providing fundamental advances, using a combination of experimental,analytical and computational methodologies, combined with field survey work with industrial partners.