Quantification of the fluid saturation of three phases of NAPL/Water/Gas in 2D porous media systems using a light transmission technique

Determining transient fluid saturations in a multi-phase system is important for understanding the system's flow characteristics and performing effective subsurface remediation. This paper investigates the models to quantify the fluid saturations of three phases of NAPL/Water/Gas in 2D porous media systems using a noninvasive light transmission technique. Four light intensity-saturation models (LISMs) to quantify fluid saturations from light intensities with only two parameters are proposed. Four LISMs can be divided into two classes: one based on assumption A of individual drainage and the other based on assumption B of combined drainage. LISMs are verified by two experiments conducted in NAPL invading into Water/Air and Water/Biogenic-Gas conditions, respectively. Results show that the model which based on assumption A and drainage of water first is the best type and show the strongest linear correlation between calculated results and measured data (R-2 of 0.974 for air condition and R-2 of 0.996 for biogenic gas condition). This study developed the innovative LISMs and applied them to three phases of NAPL/Water/Gas systems, which provides a methodology to acquire effective three fluid saturations in a continuous, quantitative, and real time way.

Automated summary

Determining transient fluid saturations in a multi-phase system is crucial for understanding flow characteristics and effective subsurface remediation. This paper investigates models for quantifying fluid saturations of NAPL/Water/Gas in 2D porous media systems using a noninvasive light transmission technique, and proposes four light intensity-saturation models. The study shows that the model based on assumption A and drainage of water first is the most accurate, with strong linear correlation between calculated results and measured data.