In this study, oil-water two phase flow was examined and the replacement process was visualized and analyzed by X-ray CT method. Here, porous rock samples were fully saturated by oil and water is pushed into the sample. As a porous sample, Berea sandstone was applied. Since the density difference between oil and water is very small for X-ray CT inspection, 10% of KI solution was used instead of water. It was found that the replacement process progressed gradually in the rock sample and that this process was clearly visualized as X-ray CT images. Moreover, the procedure to evaluate replacement ratio from CT image data was also newly introduced and the replacement ratio was estimated. It was found that the approximately 40% -50% of oil in pores were replaced by KI solution.
In the projects, such as oil productions, CCS and geothermal energy development, the analysis of multi flows in rocks is necessary. Among the projects, oil-water two phase flow is the representative two phase flow in the rock engineering (Stephan (2005), Wang (2016)). In this study, one dimensional oil-water two phase flow is examined and the replacement process is visualized by X-ray CT scanner system. Here, one-dimensional flow tests are conducted toward the porous rock sample which are initially filled with oil. As is well known, X-ray CT scanner is the system to visualize density distribution in the materials (Khalid (2010), Veerle (2013)). However, the density difference between oil and water is not large enough to visualize by X-ray CT scanner, and 10% concentration of KI solution is pushed into the rock sample instead of water for clearer visualization. Here, the procedure to obtain density difference due to the oil-KI solution replacement is firstly introduced. Then, the method to evaluate replacement ratio from CT data is induced, and the replacement process is analyzed through the evaluation of replacement ratio.
