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

在过去的10-20年里，随着公众对石油和天然气行业的监督越来越多，行业、监管机构和各级政府的注意力都集中在解决困扰该行业的严重环境管理问题上。其中最重要的是石油和天然气威尔斯井的长期安全废弃问题。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。仅在阿尔伯塔省，就有35%的威尔斯井被废弃：这个数字加起来全省约有151，000个废弃井眼。目前的大部分油井都有30 -40年或更长的历史。加拿大正在进入P&A（堵塞和废弃）时代，在可预见的未来，每年将有1000口井被废弃。环境和公共安全问题比比皆是。井筒的长期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结合。本项目为期4年，主要研究P&A作业的工程设计。该项目有两个主要目标。首先，我们将在一个更加全球化的背景下评估典型的加拿大P&A业务、油井结构和监管实践的状况。我们将对与寿命/密封相关的科学和工程文献进行详细审查，澄清知识差距并揭示技术问题。第二，通过合作的加拿大研究人员和有针对性的补充子项目的网络，我们将提供物理和工程原理的监管和运营决策，涉及流体机械问题（放置，清洁，混合，从而潜在的粘合）。我们的团队将进行7项互补和相互关联的研究，解决P&A知识差距，同时提供根本性的进步，使用实验，分析和计算方法的组合，结合与工业合作伙伴的实地调查工作。

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.