A Simplified Calibration of Liquid Hold-Up and Film Thickness in Annular Flow in Horizontal Pipe

Osokogwu Uche

doi:10.11648/j.ajme.20210703.12

Abstract

Annular flow is majorly encountered in petroleum industry, where gas and liquid are conveyed from gas wells or oil wells (dominated by gas) to the surface through the transport lines. A simplified annular flow bench calibration for liquid hold-up and film thickness in horizontal pipe was conducted using water/air in a 2-inch (50mm) Plexiglas pipe test tube with a length of 154mm. The calibration was achieved using five different acryl plastic rods inserts of 49mm, 48mm, 47mm, 46mm and 45mm with a length of 153mm respectively. The 2-inch (50mm) plexiglass test tube was installed with two pairs of conductivity ring sensors for liquid hold-up and the flush-mounted conductance probe sensor for liquid film thickness. The acts of measuring, recording and transmitting the data to a usable state were achieved using a digital data acquistion system (Labview). The conductivity ring sensors C1 and C2 results which were for the liquid hold-up in the calibration gave R-factors of 0.9962 and 0.9947 respectively, while the conductance probe sensor for the liquid film thickness presented an R-factor of 0.9949.

Highlights

Annular flow in horizontal pipe is a complex flow of gas and liquid phase flowing at different velocity to the delivery end
Annular flow in pipes flow with gas phase as the dominant phase with liquid droplets being entrained while the liquid phase is sparsely distributed circumferentially across the walls of the pipe
The above calibrations and procedures were perfect in their unique ways. This study presents these annular flow calibrations for liquid hold-up and film thickness in a simplified approach with the pipe test tube design and the acryl rods shown in appendix

Summary

Introduction

Annular flow in horizontal pipe is a complex flow of gas and liquid phase flowing at different velocity to the delivery end. The liquid film thickness results were further validated with an experimental results of air/water flow conducted on a pipe with internal diameter of 32mm and 3.9m long. For stratified and annular flow, Chao et al, [5] conducted calibration experiment using a conductance probe for measuring liquid fraction in gas-liquid flow. This study presents these annular flow calibrations for liquid hold-up and film thickness in a simplified approach with the pipe test tube design and the acryl rods shown in appendix. The essence was to enable the acryl rods to be fixed firmly at the center position of the 50mm test tube as part of the precautions for having a circumferential liquid film thickness across the pipe internal diameter. The drains were used for water passage: draining and introducing fresh water during the calibrations with a stopper as shown in the design (Appendix)

Methodology

Conclusion