Experimental Studies on Capillary pressure-Saturation Relationship Using Perspective Micro-model
Yung Chi Shih
Liang C. Chang
|關鍵字:||微模型;非水相液體;毛細壓力;飽和度;比例原則;micromodel;NAPL;Capillary pressure;Saturation;Scaling rule|
In addition to having a low solubility in water, most organic solvents are difficult to decompose naturally. While leaking into the aquifer, the organic compounds can more seriously contaminate the aquifer than other high soluble pollutants do. Therefore, understanding the fate and transport mechanism of the organic compounds in aquifer is a relevant task. This study utilizes perspective micro-model experiments and digital image analysis to obtain capillary pressure-saturation relationships for several two-phases systems including the water-air and NAPLs-air and to observe the micro-scale behavior of a multi-phases system in porous media. The experimental data from the micro-model are then used to investigate the accuracy of scaling rule. For the same porous media, the scaling rule has been widely used to estimate the capillary pressure-saturation curve of a target two-phases system based on the observed data of other two-phases system. The result indicates that the error of the estimation is proportional to the value of capillary pressure for the target phases. The higher the capillary pressure the larger the error. The micro-scale observation also reveals that a thin film of wetting fluid exists on the surface of porous matrix and that become a preferential path of the wetting phase during the imbibition process. Therefore, applying the scale rule to estimate the capillary pressure-saturation curve for the imbibition process is questionable.
|Appears in Collections:||Thesis|