Investigation of the Fate and Transport Behaviours of Spilled Oil and Development of a State-of-the-Art Canadian Oil Spill Emergency Response Model

石油和天然气资源对加拿大经济具有重要的经济意义。加拿大的石油和天然气工业不断发展，最近宣布了几个主要的石油勘探和运输项目。石油和天然气活动的增加了海洋石油泄漏的风险，由于可能造成破坏性的环境影响，这一风险令人严重关切。最近的深水地平线灾难表明，深水环境中的溢油事件给应急物流带来了极大的困难;因此，必须有一个可靠的溢油模型来预测石油的轨迹，并帮助分配有限的应急资源。目前，我国对溢油在海洋环境中的归宿和迁移行为的认识还很薄弱，迫切需要对现有的溢油模型进行改进，本研究项目旨在加深对溢油在海洋环境中归宿和迁移行为的认识，不断提高预测溢油迁移及其最终归宿的能力。目前，地下溢油建模的一个主要障碍是缺乏油滴尺寸分布的实验数据，这在确定石油的最终命运中起着关键作用。因此，本研究将通过在30 m储罐中进行中尺度实验，并以不同释放速率、分散剂剂量和油类型的组合在水下释放油来解决这一不足。液滴尺寸将通过三种不同仪器的组合来测量，以捕获从几微米到几毫米的整个液滴范围。将建立一个分布的数学模型，然后将其与现有的溢油模型相结合，以研究这些分布对油质量平衡和轨迹的影响。以前的研究表明，沿海沃茨中高浓度的悬浮沉积物可以显著改变溢油的行为，并可能导致油在海底沉降。这是由于形成了密度通常高于周围水的油-矿物聚集体。为了准确地预测石油的命运和轨迹，在溢油模型中包括这一过程是非常重要的，但现有的模型都没有考虑这一过程。因此，本研究的另一个目的是建立一个数学模型来模拟石油-矿物聚集体的形成。这将通过将单一颗粒类型聚集动力学模型扩展到不同密度的颗粒（石油和沉积物）并根据现有实验数据确定碰撞系数来实现。新的聚合模型将被纳入一个通用的石油泄漏模型，以扩大其适用性，并提高其预测的准确性，最近的墨西哥湾石油泄漏灾难表明，使用一个综合业务海洋环流/石油泄漏模型提供真实的时间预测和帮助分配有限的反应资源的重要性。由于加拿大目前缺乏这样的系统，因此本研究的目的是通过整合新的先进溢油模型来开发该系统（使用关于液滴尺寸分布和OMA形成的新知识）与加拿大东海岸经过充分验证的可操作海洋环流模型。总之，这项拟议的研究旨在不仅提高我们在漏油行为两个关键领域的知识，而且还提供了一个重要的操作工具，将帮助管理机构和溢油应急人员实时跟踪石油，并就采取适当的溢油对策做出更有效的决策。

Oil and gas resources are of significant economic importance to Canada’s economy. The oil and gas industry in Canada is continuously growing and several major oil exploration and transportation projects from coast to coast have been announced recently. Increased oil and gas activity raises the risk of marine oil spills, which is of significant concern because of the potentially devastating environmental effects. The recent Deepwater Horizon disaster has shown that spills in the deep water environment present extremely difficult response logistics; hence, it is vital that a reliable oil spill model be available to predict the trajectory of oil and help allocate the limited response resources. Unfortunately, our knowledge on the fate and transport behaviour of spilled oil in the marine environment is still very poor, and there is an urgent need to improve existing oil spill models.This research program is aimed at advancing our understanding of the fate and transport behaviour of spilled oil in the marine environment, and continuously improving our ability to predict the movement of oil and its ultimate fate. Currently, a major barrier in the modeling of subsurface oil spills is the lack of experimental data on oil droplet size distribution, which plays a critical role in determining the ultimate fate of the oil. Therefore, this research will address this lack by conducting meso-scale experiments in a 30 m tank, and releasing oil underwater in a combination of different release rates, dispersant dosage, and oil types. Droplet size will be measured by a combination of three different instruments to capture the whole range of droplets from a few microns to several millimeters. A mathematical model of the distribution will be developed and then integrated with an existing oil spill model to study the effects of the distributions on oil mass balance and trajectory.Previous studies have shown that high concentrations of suspended sediments in coastal waters can change the behavior of spilled oil significantly, and may lead to potential settling of oil at the seabed. This results from the formation of oil-mineral aggregates whose densities are often higher than that of the ambient water. To accurately predict the fate and trajectory of oil, it is very important to include this process in an oil spill model, but none of the existing models consider this process. Therefore, another objective of this research is to develop a mathematical model to simulate oil-mineral aggregate formation. This will be achieved by extending a single particle type aggregation kinetic model to particles of different densities (oil and sediments) and determining the collision coefficients based on existing experimental data. The new aggregation model will then be incorporated into a general oil spill model to extend its applicability, and to improve the accuracy of its prediction.The recent Gulf of Mexico oil spill disaster demonstrated the importance of using an integrated operational ocean circulation/oil spill model to provide real time prediction and help to allocate limited response resources. Because Canada currently lacks such a system, it is the objective of this study to develop it by integration of the new advanced oil spill model (using new knowledge on both droplet size distribution and OMA formation) with a well validated, operational, ocean circulation model for the east coast of Canada.In summary, this proposed research aims to not only advance our knowledge in two key areas of oil spill behavior, but also provide an important operational tool that will help regulatory agencies and spill responders track the oil in real-time and make more effective decisions concerning the adoption of proper oil spill countermeasures.