Energy and the shallow subsurface: from key processes to robust monitoring of geo-environmental greenhouse gases

为了应对气候变化及其对自然和建筑环境的相关影响，需要大幅减少温室气体（GHG）排放。加拿大承诺到2030年减少30%的排放量，到2050年实现“净零”排放。实现这些目标的具体行动在能源部门至关重要，例如减少化石燃料的生产，向“更清洁”的燃料（例如氢）过渡，以及实施减少碳的战略（例如地质封存）。地下在这些方法中都起着至关重要的作用，因为在脱碳后，成千上万的传统能源井将保留下来，而地下深处将用于储存新的燃料和捕获的温室气体。因此，一个主要的环境问题是地球环境温室气体可能从地表以下深处释放到浅层地下和大气中。这种释放可能进一步导致温室气体排放，并威胁饮用水地下水资源。由于对浅层地下气体运移控制过程的知识有限，以及缺乏准确的监测技术，总体影响无法很好地量化。拟议的研究计划旨在促进对浅层地下温室气体运动和命运的定量了解，并利用基于过程的知识来制定监测和减缓战略。重点是了解加拿大能源部门自然景观中非稳态条件下（即压力和温度变化）浅层地下的气体运动和溶解，并开发检测泄漏气体的新方法。一个由7名高素质人员（HQP）组成的小组将利用中等规模（厘米到米）的实验室实验与数值模拟相结合，开展一套补充性的研究任务。该团队将：1)量化能源部门与地球环境温室气体相关的环境影响；2)提供高分辨率数据集，建立驱动地下天然气运动和命运的过程知识；3)开发和验证数值模型，以评估各种尺度的影响；4)测试监测方法，准确发现异常气体的迹象和症状。研究结果对学者、从业人员和政策制定者都很有价值，可以识别和优先考虑需要退役的传统能源井，安全设计和运营未来能源项目，量化风险，并为监管和政策决策提供基于科学的见解。该项目还将为HQP提供独特的培训，使他们能够解决加拿大未来面临的复杂环境挑战。最终，从这项研究中获得的知识将通过保护地下水、土壤和大气来支持加拿大能源部门的地下脱碳工作。

Substantial reductions of greenhouse gas (GHG) emissions are required to address climate change and the associated impacts on the natural and built environment. Canada has committed to reducing emissions 30% by 2030 and decarbonization to achieve "net-zero" emissions by 2050. Specific actions to achieve these goals are crucial in the energy sector, such as reducing the production of fossil fuels, transitioning to "cleaner" fuels (e.g., hydrogen), and implementing carbon reduction strategies (e.g., geological sequestration). The subsurface plays a critical role in each of these approaches, as thousands of legacy energy wells will remain after decarbonization and the deep subsurface will be used to store new fuels and captured GHGs. As a result, a major environmental concern is the potential release of geo-environmental GHGs from deep below the earth's surface to the shallow subsurface and atmosphere. This release may further contribute to GHG emissions and threaten potable groundwater resources. The overall impacts are not well quantified due to limited knowledge of the processes governing gas migration within the shallow subsurface and a lack of accurate monitoring techniques. The proposed research program seeks to advance quantitative understanding of the movement and fate of GHGs in the shallow subsurface and leverage process-based knowledge to develop monitoring and mitigation strategies. The focus will be on understanding gas movement and dissolution in the shallow subsurface under non-steady state conditions (i.e., pressure and temperature variation) expected across the natural landscape of the Canadian energy sector and to develop novel approaches for the detection of leaked gas. A team of seven highly qualified personnel (HQP), will conduct a complementary set of research tasks, using intermediate-scale (centimetre-to-metre) laboratory experiments coupled with numerical modelling. This team will: 1)Quantify the environmental impacts associated with geo-environmental GHGs in the energy sector; 2)Provide high-resolution datasets to establish knowledge of processes driving subsurface gas movement and fate; 3)Develop and validate numerical models to assess impacts across a variety of scales; 4)Test monitoring approaches to accurately detect signs and symptoms of anomalous gas. The results will be valuable to academics, practitioners, and policymakers, allowing identification and prioritization of legacy energy wells requiring decommissioning, safe design and operation of future energy projects, quantification of risk, and providing science-based insight for regulation and policy decisions. This program will also provide unique training to HQP allowing them to solve the complex environmental challenges Canada faces into the future. Ultimately, the knowledge gained from this research will support subsurface decarbonization efforts in the Canadian energy sector by protecting groundwater, soils, and the atmosphere.