Non-intrusive characterization of sand particles dispersed in gas–water bubbly flow using straight and bent pipes with vibration sensing

Abstract

The transport of a solid dispersed in a gas-water bubbly pipe flow is widely encountered in petroleum engineering. In this paper, the characterization of solid particles dispersed in a water-gas bubbly flow was developed based on vibration sensing from straight and bent pipes. Typical frequency-domain analysis, time-domain statistical analysis, and time-domain joint analysis were applied for sand-vibration signal identification and characterization. Verification experiments were performed, and good agreements were found between the sand concentration (0–0.24 wt%) with uniformly mixed sand size (300–600 μm) and sand-vibration energy in water flow and water-gas bubbly flow. Characteristic frequency bands of 4–5 kHz (horizontal straight pipe), 3.9–5 kHz (bent pipe), and 4.7–5 kHz (vertical straight pipe) were found. The sensor installed on a bent pipe obtained the highest vibration energy of water/water-gas bubbly flow among tested pipes; with the increase of sand injected, a sensor installed on the outer wall at 45° on the elbow obtained the most obvious vibration energy caused by sand–wall interaction. The validity of the detected sand signals was verified using an acoustic sensor. In summary, the vibration-sensing method is applicable to characterize solid particles in water-gas bubbly pipe flow.