低炭素社会構築のためのCCS（3）

[1507-10-03] 多孔質内の化学反応による混和性ヴィスカスフィンガリングの三次元可視化

○シン ソテアヴット¹、末包 哲也¹ (1. 東京工業大学)

司会:佐々木 久郎(九州大学)

キーワード：三次元、混和性ヴィスカスフィンガリング、粘性増加、粘性減少、化学反応

Viscous fingering is a hydrodynamical flow instability occurring when a more-viscous fluid (MVF) is displaced by another less-viscous fluid (LVF) and take place in either miscible and immiscible systems. In this study, we investigate the three-dimensional characteristics of miscible viscous fingering with chemical reactions using a microfocus x-ray computed tomography (CT) scanner and we also visualize the two-dimensional images of the fingers to see how the concentration and the viscosity of the displacing fluid change along the finger with respected to the color calibration using image processing (ImageJ). With an increase in the Péclet number for the viscosity increase system, the length extension of the tip of the most-advancing finger remains unchanged in the reactive case, but it contrastingly decreases in the non-reactive case. For the viscosity decrease system of either the reactive case and the non-reactive case, however, the length extension of the tip of the most-advancing finger decreases with increasing the Péclet number. The maximum concentration of NaI in LVF inside the finger linearly decreases while it sharply decreases at the tips of the fingers. An increase in viscosity due to the chemical reactions causes the finger widening and the suppression of the shielding effect. A decrease in viscosity due to the chemical reactions, however, causes the finger narrowing and the enhancement of the shielding effect. As a result, the received sweep efficiency from the reactive case is larger than that in the non-reactive case for the viscosity increase system. In contrast, the received sweep efficiency from the reactive case is smaller than that in the non-reactive case for the viscosity decrease system.