The porosity of porous media is an important factor affecting the water-air two-phase displacement mode and injection saturation,with the later being the key index to determine the leaching rate of ion-type rare earth ore.By conducting microfluidic model experiments on water-air two-phase displacement in porous media with four different porosities,the water-air two-phase displacement mode was determined,the formation mechanism and distribution characteristics of air clusters were analyzed,and the influence of porosity on the injection saturation in the model was studied.The results indicate that the water-air two-phase displacement under the experimental conditions is in the capillary fingering displacement mode,and the fingering phenomenon is more significant in the case of high porosity.With the increase of capillary number,the seepage pattern tends to be stable.The air clusters are easily formed in the pores of porous media in the capillary fingering process,where the air clusters in the low porosity model are small and numerous while those in the high porosity model are large and small.The injection saturation in the model decreases with increasing porosity and increases with increasing injection intensity.
关键词
水气两相流/多孔介质/孔隙率/毛细管指进/饱和度
Key words
water-air two-phase flow/porous media/porosity/capillary fingering/degree of saturation
维普
万方数据