Recently, for the extraction of unconventional petroleum resources, the SAGD (Steam-Assisted Gravity Drainage) method, which uses high-temperature steam to reduce the viscosity of bitumen, is widely used. In particular, the importance of the Watercut meter system is increasing because the oil sand mining technology is an additional and more complicated process than oil extraction in general oil wells. In this study, a numerical analysis of the ultrasonic-based SOR (steam to oil ratio) ratio change for heavy oil was performed. As a result of the analysis, the maximum sound pressure and the ultrasonic arrival time were analyzed using the SOR ratio as a variable. The higher the water-to-oil ratio, the higher the maximum sound pressure and the shorter the ultrasonic arrival time. On the other hand, the higher the oil ratio, the lower the maximum sound pressure and the longer the ultrasonic arrival time. It is judged that the data set on the moisture content in oil can be constructed using the numerical analysis results, and it can be used as a basis for the reverse engineering of Watercut.