本文利用在不同流率下異質孔隙流的壓力變化，來瞭解流體在多孔介質的流動特徵及驅替行為。實驗採用線性Hele-Shaw cell，其中以光刻的方式使內部填滿圓柱結構，而圓柱間形成多個孔隙通道，稱為多孔介質。當在多孔介質內低黏度流體推動高黏度流體時，由於黏性指形的影響，會遺留黏性流體在介質內，降低了多孔介質內黏性流體的驅替效果。實驗設計了五種大、小粒徑顆粒所占長度比例不同的異質孔隙結構組合，分別為小顆粒占全長的百分比例λ=0、0.25、0.5、0.75、1，並分析不同注入流率的實驗結果。 實驗結果發現，隨著長度比增加，黏性壓降逐漸變小，且實驗得到的黏性壓降在相同長度比下低於理論估算值，推測指形在多孔介質內流動受到空氣黏性壓降的影響導致黏性壓降偏低。另外對於空氣的驅替變化，空氣飽和度隨著長度比增加有上升的趨勢，但由於異質界面上的毛細壓力差異不大，在界面上無明顯阻擋效果，造成在大顆粒區域內驅替面積無明顯的上升。 ;This research presents the experimental studies of unstable activity during drainage in porous media. We show the pressure variation of fluid displacement through the porous media with different volume flowrate, to understand the flow feature and displacing behavior. We used horizontal linear Hele-Shaw cells involve pore-scale cylindrical obstacle as an experimental model. The less viscous fluid (air) displaces the more viscous fluid (water) through the porous media, the finger-like flow patterns formed in the medium, which decrease the viscous fluid displacement. We design heterogeneous porous models consisting of five kinds of length ratio of small-particles filling length to large-particles filling length, equal to 0, 0.25, 0.5, 0.75, 1, for investigating physical mechanism that influences the flow displacement. The results show that the experimental viscous pressure drops of five kinds of length ratio are lower than the theoretical values because the air viscous drag is included. The air saturation increase with increasing length ratio. However, the small capillary difference between the heterogeneous interface of porous media, the displacement is not influenced by the capillary difference.
