Capacitive Phase Shift Detection for Measuring Water Holdup in Horizontal Oil–Water Two-Phase Flow

Abstract

In this paper, a phase shift detection system of flow impedance is designed based on a concave capacitance sensor (CCS). The flow impedance of oil–water stratified flow is investigated by establishing an equivalent circuit model and a finite element model. The influence of exciting frequency and sensor geometric parameters on the phase shift output of the CCS is studied to access an optimal phase shift measurement system. An experiment of horizontal oil–water two-phase flows was conducted during which four flow patterns are observed, i.e., stratified flow (ST), stratified wavy flow (SW), dual continuous flow (DC), and dispersed oil-in-water and water flow (DO/W&W). The phase shift responses of the CCS to the water holdup variation are collected. The results indicate that the phase shift response of the CCS presents satisfied sensitivity for ST and SW flow patterns, which is consistent with the predictions of the equivalent circuit model and the finite element model. Although the flow structures of DC and DO/W&W flows are extremely nonuniform, the phase shift response of the CCS still shows better linearity and sensitivity to the water holdup variation. In general, the capacitive phase shift detection technology exhibits advantages for water holdup measurement in horizontal oil–water two-phase flow with nonuniform phase distributions and conductive water.

The Influence of Large Variations in Fluid Density and Viscosity on the Resonance Characteristics of Tuning Forks Simulated by Finite Element Method

“…The smoke and dust content of engine oil can be monitored by measuring its density and viscosity through tuning forks [4,5]. In the process of oil and gas exploitation, using a tuning fork to measure the density and viscosity of downhole fluid can identify fluid, determine fluid composition and divide oil-water interface, which is of great significance for optimizing oil and gas reservoir management and intelligent oil field exploitation [6][7][8][9][10][11].…”

The Influence of Large Variations in Fluid Density and Viscosity on the Resonance Characteristics of Tuning Forks Simulated by Finite Element Method

“…The smoke and dust content of engine oil can be monitored by measuring its density and viscosity through tuning forks [4,5]. In the process of oil and gas exploitation [6,7], using a tuning fork to measure the density and viscosity of downhole fluid can identify fluid [8,9], determine fluid composition, and divide the oil-water interface, which is of great significance for optimizing oil and gas reservoir management and intelligent oil-field exploitation [10,11].…”

Comparison Between 180° and 360° Double Helix Capacitance Sensors for Measuring Water Holdup of Horizontal Oil–Water Stratified Flows

“…Previous studies have tried various configurations of electrodes to reduce the nonuniformity of the sensitivity of capacitance sensors [1]. Due to simple structures and quick response, capacitance sensors with concave and double-ring configurations have wide applications in the holdup measurement of gas-liquid and liquid-liquid two-phase flow [2], [3], [4], [5], [6], [7], [8], [9]. Accurate measurement of flow parameters requires an efficient capacitance measurement system.…”