Multiphysics of Fluid-Saturated Geomaterials and Chemically Damaged Barriers

流体饱和岩土材料和化学损伤屏障的多物理场

• 批准号: RGPIN-2016-04676
• 负责人: Selvadurai, Antony
• 金额: $ 4.37万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=615233
• 关键词: Multiphysics; Fluid; Saturated; Geomaterials; Chemically

This research will develop innovative experimental techniques and theoretical models of coupled processes in geomaterials and implement the approaches in computational schemes that can examine and predict the outcome of geologic disposal and containment strategies important to energy resources recovery, nuclear waste management, geologic sequestration of greenhouse gases and geothermal energy extraction. The role of multiphysics couplings needs to be understood in the context of the interaction of thermal (T), hydraulic (H), mechanical (M) and chemical (C) processes. The emphasis of the research program is to achieve the necessary advances in theoretical, computational and experimental procedures that have immediate applications to geoenvironmental protection strategies. The highly heterogeneous Cobourg Limestone, targeted by the Nuclear Waste Management Organization, ON, for deep geological storage of radioactive wastes, will be studied using large cylindrical samples (150 mm dia., 300 mm long). The internal features of the rock present a challenge in terms of multi-scale coupled processes and for this reason, experiments will be performed using the recently acquired Triaxial Cell with Acoustic Emission Tomography mapping capabilities, to progressively track defect evolution that will affect the THM responses. This equipment is unique to Canada. Using the experimental results, reliable models of the THM behaviour of Cobourg Limestone will be achieved to predict the long-term scenarios of NWMO initiatives. The research will also examine THMC effects in geologic storage of CO2 in carbonate reservoirs since the targeted storage horizons in Canada are largely carbonate rocks. Preliminary studies reveal that wormholes or dissolution channels develop rapidly in carbonate-rich samples; this will affect the storage potential of the aquifer and compromise the structural support that provides stability for caprock barriers. Storage rocks from Weyburn, SK, Brooks, AB and Bécancour, QC will be tested and models developed to relate chemical erosion at fractures and sealing interfaces to alterations in geostatic stress states and carbonate content. Research will also address the role of chemicals on the mechanics of geosynthetics, particularly their embrittlement due to plasticizer removal, and examine the stress-assisted transport of chemicals in geomembranes leading to anisotropic effects. Rate-sensitive constitutive models will be developed; these could be used to predict tearing failure at defects, at connecting seams and, in particular, the localized regions of action of chemicals such as ethanol. Over the next five years, the research program will train PDFs, PhDs, Masters and UG students, with skills to effectively contribute to these areas. The projects will have a significant impact on the development of policy for the protection of the environment.

这项研究将开发岩土材料耦合过程的创新实验技术和理论模型，并在计算方案中实施这些方法，这些方法可以检查和预测对能源资源回收、核废料管理、温室气体地质封存和地热能提取很重要的地质处置和遏制策略的结果。需要在热 (T)、液压 (H)、机械 (M) 和化学 (C) 过程相互作用的背景下理解多物理场耦合的作用。该研究计划的重点是在理论、计算和实验程序方面取得必要的进展，这些进展可立即应用于地球环境保护战略。 安大略省核废物管理组织针对高度异质的科堡石灰石进行放射性废物深层地质储存，将使用大型圆柱形样品（直径 150 毫米，长 300 毫米）进行研究。岩石的内部特征在多尺度耦合过程方面提出了挑战，因此，将使用最近获得的具有声发射断层扫描绘图功能的三轴单元进行实验，以逐步跟踪将影响 THM 响应的缺陷演变。该设备是加拿大独有的。利用实验结果，将获得科堡石灰石 THM 行为的可靠模型，以预测 NWMO 举措的长期情景。 该研究还将研究 THMC 对碳酸盐岩储层中 CO2 地质封存的影响，因为加拿大的目标封存层位主要是碳酸盐岩。初步研究表明，虫洞或溶解通道在富含碳酸盐的样品中迅速形成；这将影响含水层的储存潜力，并损害为盖层屏障提供稳定性的结构支撑。来自SK的Weyburn、AB的Brooks和QC的Bécancour的储存岩石将进行测试并开发模型，以将裂缝和密封界面的化学侵蚀与地静应力状态和碳酸盐含量的变化联系起来。 研究还将解决化学品对土工合成材料力学的作用，特别是由于增塑剂去除而导致的脆化，并检查土工膜中化学品的应力辅助传输导致各向异性效应。将开发速率敏感的本构模型；这些可用于预测缺陷处、连接缝处的撕裂失效，特别是乙醇等化学品的局部作用区域。 在接下来的五年中，该研究项目将培训 PDF、博士、硕士和 UG 学生，让他们掌握有效为这些领域做出贡献的技能。这些项目将对环境保护政策的制定产生重大影响。