Detecting droplets and bubbles in oil–gas–water three-phase medium via ultrasonic A-scan signal-assisted B-mode imaging method

Abstract Accurately detecting the parameters of bubbles and droplets in an oil–gas–water three-phase medium is essential to critical decision-making in industrial production. An ultrasonic A-scan signal-assisted B-mode imaging (AS-assisted-BI) method that combines a B-mode imaging (BI) method and an A-scan signal (AS) method is developed to simultaneously visualize the oil–gas–water three-phase medium, distinguish the gas bubbles and oil droplets, and measure their size and location parameters. The applicability of the plane wave imaging (PWI) method for visualizing the oil–gas–water three-phase medium with less computational cost was confirmed. Then, the influence of the bubble and droplet characteristics, such as the acoustic impedance difference, size, and location, upon the ultrasonic propagation mechanism were studied to understand the B-mode image and A-scan signal as the design basis for the BI and AS method. The BI method locates the least key points from the B-mode image based on the PWI method compared with the conventional industrial ultrasonic B-mode imaging method. The AS method automatically locates the key points from the A-scan signal rather than manually marking them as in previous studies. Two options for the AS-assisted-BI method, suitable for different detection requirements and applications, have been designed. The numerical simulation and experimental results demonstrate that the proposed method has excellent precision, robustness, and efficiency for detecting the acoustic impedance difference between the bubbles and droplets, the longitudinal location of the bubble front surface, and the droplet’s size and center location.