Measurement of fluid contents by light transmission in transient three-phase oil-water-air systems in sand

Most three‐phase flow models lack rigorous validation because very few methods exist that can measure transient fluid contents of the order of seconds of whole flow fields. The objective of this study was to develop a method by which fluid content can be measured rapidly in three‐phase systems. The method uses the hue and intensity of light transmitted through a slab chamber to measure fluid contents. The water is colored blue with CuSO4. The light transmitted by high‐frequency light bulbs is recorded with a color video camera in red, green, and blue and then converted to hue, saturation, and intensity. Calibration of hue and intensity with water, oil, and air is made using cells filled with different combinations of the three fluids. The results show that hue and water content are uniquely related over a large range of fluid contents. Total liquid content is a function of both hue and light intensity. The air content is obtained by subtracting the liquid content from the porosity. The method was tested with static and transient experiments. Measurements made with the light transmission method (LTM) and synchrotron X rays of the static experiment agreed well. In the transient experiments, fingers were formed by dripping water on the surface in a two‐dimensional slab chamber with partially oil‐saturated sand. The LTM is able to capture the spatial resolution of the fluid contents and can provide new insights in rapidly changing, three‐phase flow systems.