研究期間：10205~10307;Multiphase flow in porous media is an important mechanism of subsurface hydrology, and capillary pressure is one of the major driving forces of the flow. The effects of dynamic capillary pressure should be important when rain first enters a dry soil in extreme weather events, when water displaces oil during water-flooding of oil reservoirs, or when supercritical CO2 is injected into aquifers for the purposes of carbon sequestration. The purposes of this study are to analyze the effects of liquid wettability on the dynamic capillary pressure and to understand the link between pore-scale dynamic contact angle and the (Darcy-scale) dynamic capillary pressure. The Darcy-scale column experiments will be performed to show the dynamic capillary effects when liquids enter a porous medium. The change of the liquid interface and contact angle will be recorded and measured by using a special pore-scale multiphase-flow observation system. In the end, we will compare the results of Dacry-scale and pore-scale experiments to link the dynamic contact angle to the dynamic capillary pressure. The estimated duration of this project is about one year and five months. The equipment purchases and experimental setup will be finished in the first five months, and the experiments and data/image analysis will be performed during the next twelve months. In the end, we expect to better understand the effects of the liquid/solid properties on the dynamic capillary pressure and to see a clear picture of the link between dynamic capillary pressure and the dynamic contact angle. In addition, the pore-scale multiphase flow observation system will be a flow-visualization tool for future studies.
