Modelling of Gravity Flows in Porous Media: Implications for the Geological Sequestration of Carbon Dioxide.

目前全球二氧化碳的人为排放量约为每年23千兆吨。大气中大量二氧化碳这种温室气体的引入对未来气候的影响引起了全世界的极大关注。减少环境破坏的一种可能方法是将二氧化碳储存在某个地方，直到化石燃料时代结束。在生态系统和海洋底部储存的建议充满困难，而且非常昂贵。目前正在认真考虑通过将液态或超临界二氧化碳直接注入多孔储集岩（例如存在于枯竭的油气田和区域盐水层中的储集岩）来进行储存。该项目旨在确定预期的传播速度和形式。它建立在初步研究的PI调查的轴对称流的液体输入从一个点源以上的不可渗透的边界到一个多孔介质饱和的液体的不同密度。目前的工作旨在研究真实的情况下，其中包括：一个倾斜的边界;一个轻微的渗透性边界;有限大小的源;多孔介质的各向异性;和两种液体的不同粘度的影响。将进行理论分析，并将结果与专门进行的实验室实验进行比较。新的结果和理解将用于调查和解释Sleipner天然气田目前的二氧化碳封存。

Current global anthropogenic emissions of carbon dioxide are approximately 23 Gigatonnes per year. The influence of the introduction of this large amount of carbon dioxide, a green-house gas, in the atmosphere on future climate has raised huge concerns worldwide. A possible means of reducing the environmental damage is to store the carbon dioxide somewhere until well past the end of the fossil fuel era. Suggestions of storage in ecosystems and at the bottom of the oceans are fraught with difficulties and are very expensive. Storage by direct injection of liquid, or supercritical, carbon dioxide into porous reservoir rocks, such as exist in depleted oil and gas fields and in regional saline aquifers, is being seriously considered. This project aims to identify the rate and form of propagation to be expected. It builds on an initial study of the PIs investigating the axisymmetric flow of liquid input from a point source above an impermeable boundary into a porous medium saturated with liquid of a different density. The current work aims to examine the effects of real situations, which include : a sloping boundary; a slightly permeable boundary; a source of finite size; anisotropy of the porous medium; and different viscosities of the two liquids. Theoretical analyses will be carried out and the results compared with specially conducted laboratory experiments. The new results and understanding will be used to investigate and interpret the current sequestration of carbon dioxide at the Sleipner natural gas field.