The Flow Characteristics of Carbon Dioxide in Microtube and Simulated Porous Media

The flow characteristics of carbon dioxide in microtubes with the diameters of 2.05, 5.03 and 10.1 mu m are investigated experimentally. The results indicate that the flow characteristics of carbon dioxide in microtube with the diameter of 10.1 mu m are in accordance with the conventional theory; but with the decrease of the inner diameter of microtube, the results deviate from the predictions of non-slip boundary theory in microtubes with the diameter of 2.05, 5.03 mu m, and agree with theoretical predictions of first-order slip boundary theory. Microscale effect appears apparently in gaseous flow, which increases as the diameter of microtubes decrease. The extent of microscale effect can be characterized by the size of kn, and the larger kn, the stronger microscale effect. Based on capillary bundle model, the gas seepage properties in low-permeability porous media influenced by microscale effect are researched. The results show that carbon dioxide percolation has obvious characteristic of non-darcy flow, which is accordance with Klinkenberg effect.