Sealing, Plugging and Visco-plastic Networks

点击翻译按钮获取中文摘要

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