King Thomas L, Robinson Brian, Cui Fangda, Boufadel Michel, Lee Kenneth, Clyburne Jason A C
Department of Fisheries and Ocean Canada, Centre for Offshore Oil, Gas and Energy Research, Bedford Institute of Oceanography, Dartmouth, Nova Scotia B2Y 4A2, Canada.
Environ Sci Process Impacts. 2017 Jul 19;19(7):928-938. doi: 10.1039/c7em00118e.
Canada's production, transport, and sale of diluted bitumen (dilbit) products are expected to increase by a million barrels per day over the next decade. The anticipated growth in oil production and transport increases the risk of oil spills in aquatic areas and places greater demands on oil spill capabilities to respond to spills, which have raised stakeholder concerns. Current oil spill models only predict the transport of bitumen blends that are used in contingency plans and oil spill response strategies, rather than changes in the oil's physical properties that are relevant to spill response. We conducted weathering studies of five oil products (two conventional oils and three bitumen blends) in the Department of Fisheries and Oceans' flume tank. We also considered two initial oil slick thicknesses, 4.0 mm and 7.0 mm. We found that there is a major difference in the time evolution of oil properties (density and viscosity), raising doubts on weathering models that do not consider the thickness of oil. We also developed empirical expressions for the evolution of the density and viscosity of these oil products. The findings from the 4.0 mm results were incorporated with data from the literature to provide an update on the factors to consider during the decision making for spills of diluted bitumen products. The matrix indicated that most response options, including chemical dispersants, work much more effectively within 48 hours of the initiation of weathering. After this window of opportunity closes, natural attenuation or in situ burning is the only option remaining, but containment of oil is a limiting factor for in situ burning.
预计在未来十年内，加拿大稀释沥青（dilbit）产品的生产、运输和销售量将每天增加100万桶。预计石油生产和运输的增长会增加水生区域发生石油泄漏的风险，并对石油泄漏应对能力提出更高要求，这引发了利益相关者的担忧。目前的石油泄漏模型仅预测应急计划和石油泄漏应对策略中使用的沥青混合物的运输情况，而不是与泄漏应对相关的石油物理性质的变化。我们在渔业和海洋部的水槽中对五种石油产品（两种常规油和三种沥青混合物）进行了风化研究。我们还考虑了两种初始油膜厚度，即4.0毫米和7.0毫米。我们发现，石油性质（密度和粘度）随时间的变化存在重大差异，这使人们对未考虑油厚度的风化模型产生怀疑。我们还为这些石油产品密度和粘度的变化建立了经验表达式。4.0毫米厚度实验结果的发现与文献数据相结合，为稀释沥青产品泄漏决策过程中应考虑的因素提供了最新信息。该矩阵表明，大多数应对措施，包括化学分散剂，在风化开始后的48小时内效果更佳。在这个机会窗口关闭后，自然衰减或原位燃烧是唯一剩下的选择，但对石油的围堵是原位燃烧的一个限制因素。
