Sealing, Plugging and Visco-plastic Networks

液固密封无处不在。在一般情况下，密封流体在压力下被驱动到管道/通道中，管道/通道可以系统地或随机地连接到其他管道/通道。流体渗透到一定深度，然后通常在原位硬化以密封或堵塞管道/通道或多孔网络。流体的范围从牛顿流体（如树脂）到强非牛顿流体（如粘液、化妆品面霜、膏状物），这些液体可能是聚合凝胶、细悬浮液和/或可能含有悬浮颗粒。这里的例子包括：挤压胶结、防潮注入、混凝剂、瓷砖灌浆、地质储存库（核废料、碳捕获和储存）入口密封、隧道灌浆、涂化妆品面霜……其他一些流动类似，但涉及去堵塞，例如肺通道粘液，稠油油藏流动。通常情况下，我们必须应对以下问题：流动几何形状的不规则性、不同的流动情况（流动、侵入/放置或置换）、操作的不确定性。评估流体的放置可能有困难，但所有这些应用都至少需要成功的概率估计，例如，预期的渗透深度及其方差。这些平凡的过程具有重大的社会影响。流行病学证据[1]表明，暴露于潮湿的室内环境与上呼吸道、喘息和哮喘症状之间存在明确关联。不列颠哥伦比亚省泄漏的油井平均每口井释放约24.15吨甲烷，这是一种破坏性的温室气体。到目前为止，加拿大老化的核电站已经生产了约290万束燃料，储存在地面的筒仓中，等待永久的地质储存。深部地质设施涉及对岩石和入口隧道的密封，对岩石和密封材料都进行了广泛的材料研究。在一个老化的反应堆需要更换的关键时刻，以及核能作为少数几个可以替代化石燃料的清洁能源之一的关键时刻，在大约1000年的时间尺度上，相对小容量的有效储存影响着全世界公众对核能可行性的看法。如果没有碳捕获与封存（CCS），避免危险的气候变化的成本将是现在的两倍，见b[4]。然而，CCS的可行性需要越来越有效的密封方法和准确的泄漏估计。该项目解决了多孔网络中粘塑性密封流体流动的基本问题，结合建模、计算和实验来研究物理网络，同时也利用我们模型中开发的知识和物理直觉来解决更广泛的网络/数据科学导向的问题。将遵循以下4个相互关联的子项目。(i)单孔动力学（ii）流动和堵塞网络模型（iii）三维粘塑性多孔介质流动的快速计算（iv）粘塑性流体的体系识别和渗流

Liquid-to-solid sealing is everywhere. In the general setup a sealing fluid is driven under pressure into a pipe/channel, which may connect to others, either systematically or randomly. The fluid penetrates to a certain depth, then typically hardens in situ to seal or plug the pipe/channel, or porous network. Fluids range from Newtonian (e.g. resins) to strongly non-Newtonian (e.g. mucus, cosmetic creams, pastes), which may be polymeric gels, fine suspensions and/or may contain suspended particles. Examples here include: squeeze cementing, damproofing injection, coagulants, tile grouting, sealing entry to geological storage (nuclear waste, carbon capture and storage), tunnel grouting, applying cosmetic creams, ... Some other flows are similar but involve de-plugging, e.g. mucus in lung pathways, heavy oil reservoir flows. Characteristically, we have to contend with: irregularity in the flow geometry, different flow scenarios (flow, invasion/placement or displacement), operational uncertainty. There may be difficulty to evaluate the fluid placement, but all these applications require at least a probabilistic estimate of success, e.g. an expected penetration depth and variance thereof. These mundane processes have significant societal impact. Epidemiological evidence [1] shows a clear association between exposure to damp indoor environments and upper respiratory, wheezing and asthma symptoms. Leaking wells in British Columbia release an average ~24.15 tonnes or methane per well [2], a damaging greenhouse gas. To date, Canada's aging nuclear power stations have produced ~2.9 million fuel bundles, stored in silos at surface awaiting permanent geological storage. Deep geological facilities involve sealing to the rock and entrance tunnels, with extensive materials research on both the rocks and sealing materials [3]. Effective storage of relatively small volumes over ~1000 year timescales affects public perception worldwide of nuclear energy's viability, at a critical time when aging reactors need replacing and when nuclear persists as one of the few clean energy sources viable to replace fossil fuels. Avoiding dangerous climate change will cost twice as much without Carbon Capture & Storage (CCS), see [4]. However, the viability of CCS needs increasingly effective sealing methods and accurate leakage estimates [5]. This project addresses fundamental questions underlying the flow of viscoplastic sealing fluids in porous networks, combining modelling, computation and experimentation to study physical networks, but also using knowledge and physical intuition developed in our models to address broader network/data science oriented questions. The following 4 interlinked sub-projects will be followed. (i)Single pore dynamics (ii)Network models of flow and plugging (iii)Fast computation of 3D visco-plastic porous media flows (iv)System identification and percolation with viscoplastic fluids See full proposal for references