MRI velocity measurements of water flow in porous media containing astagnant immiscible liquid

Abstract

To investigate the flow characteristics of water in a porous mediumwith a second, stagnant, immiscible liquid phase, we experimentally studiedflow of water through a bed of glass beads containing stagnant silicone oil.For imaging, two magnetic resonance imaging (MRI) techniques were used: thechemical shift imaging method and the phase-encoding method. Two-dimensionalimages both with and without the silicone oil showed that the water velocityprofiles drastically changed because the stagnant silicone oil changed thepore structure. Significant changes in flow were also confirmed by composingeleven two-dimensional images of velocity profiles to visualize thethree-dimensional flow path and the stagnant silicone oil distribution in theporous media. A statistical method was developed to clarify the relationbetween pore structure and fluid flow. This method showed that, when stagnantsilicone oil is present, but with the same net flow of water, the reduction inrate of flow from large, oil-blocked pores is compensated by an increase inrate of flow from the larger number of small pores.