Volume 25, Issue 1 (March 2002)
Determination of Water Saturation Using Miniature Resistivity Probes During Intermediate Scale and Centrifuge Multiphase Flow Laboratory Experiments
Physical modeling is essential to the conceptual understanding of the mechanisms governing multiphase flow in porous media. However, the need for accurate data is hampered by the limited amount of appropriate instrumentation designed to measure fluid saturation in three-fluid phase flow experiments. In centrifuge testing, this is accentuated by the fact that the instruments must be small and resistant to the effects of increased gravity. Miniature resistivity probes, developed at Cambridge University Engineering Department (CUED), were used to determine water saturation variations during a centrifuge test and a 1 g two-dimensional multiphase flow experiment. These experiments were conducted to study the migration of light non-aqueous phase liquids (LNAPL) in unsaturated sands. Prior to the tests, the resistivity probes were calibrated against the water saturation of unsaturated sand samples. The calibration relationship was compared to Archie's law. The miniature probes proved to be a valuable tool for monitoring water saturation variations during three-fluid phase flow under 1 g conditions, as well as under the accelerated gravity field of 20 g.