MATHEMATICAL AND EXPERIMENTAL INVESTIGATION OF TAYLOR BUBBLE-INDUCED HYDROSTATIC PRESSURE REDUCTION IN NO-OVERFLOW VERTICAL TUBE

Abstract

Taylor bubbles are commonly found in the petroleum, chemical, and energy industries. Typically, a Taylor bubble decreases hydrostatic pressure due to its lower density than the surrounding fluid. However, this study identifies an additional mechanism for Taylor bubble contributing to hydrostatic pressure reduction. This effect arises from the dynamic upward motion of the Taylor bubble, where the bubble tends to push the surrounding liquid upward, depending on its buoyancy. An experiment was conducted in which a single Taylor bubble was injected into a vertical tube. A pressure drop from 6500 Pa to 6370 Pa and from 6500 Pa to 6141 Pa was observed when injecting 3 mL and 13 mL of Taylor bubble volume, respectively. The rise speed and diameter of the Taylor bubble, as well as the speed and thickness of the liquid film around it, were measured using a pulse-echo ultrasonic technique. The ultrasonic measurements showed that instantaneous upward and downward flow rates were not equal. The upward flow rate was dominant, which caused a drop in pressure at the bottom of the tube. Finally, these findings can help these industries to predict the bottom hole or pipe pressure accurately.