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

目前全球人为二氧化碳排放量约为每年230亿吨。大气中大量的二氧化碳，一种温室气体，对未来气候的影响在世界范围内引起了极大的关注。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后很久。在生态系统和海底储存的建议充满了困难，而且代价非常高昂。正在认真考虑将液体或超临界二氧化碳直接注入孔洞储集层岩石的储存方式，例如存在于枯竭油气田和区域含盐含水层的储集层。该项目旨在确定预期的传播速度和形式。它建立在PI的初步研究的基础上，该PI研究从不渗透边界上方的点源输入到饱和了不同密度的液体的多孔介质中的液体的轴对称流动。目前的工作旨在研究实际情况的影响，这些情况包括：倾斜边界；略具渗透性的边界；有限大小的源；多孔介质的各向异性；以及两种液体的不同粘度。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。新的成果和认识将用于调查和解释斯莱普纳天然气田目前的二氧化碳封存情况。

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.