Study of oil-water fluids through of the sensor based on the electrical permittivity of the fluid pattern

A sensor based on the electrical permittivity of the fluid was used to analyze the tomographies of the different patterns that appear in multiphase oil and water flow (Liquid-Liquid). The experimental study was carried out in a borosilicate glass tube with an internal diameter of 25.4 [mm] and length of 12 [m]. The sensor is made up of two 8 x 8 wire flat wire mesh called a wire mesh sensor (WMS). The experiments were carried out with two different oil viscosities, one with 200 [cP] and the other with 60 [cP] at 860 [kg / m3]density with the tube positioned horizontally and slightly inclined at + 5 degrees, to vary the viscosity of the oil, a heat exchanger was used. The analyzed multiphase flow pattern was annular, stratified and dispersed. The tomographies obtained by the WMS were compared with a high-speed camera for the qualitative validation of the results. Twelve models of electrical permittivity were used to study the current fluid regime.Un sensor basado en la permitividad eléctrica del fluido fue usado para análisis de las tomografías en los diferentes patrones que se presentan en flujo multifase aceite y agua (Liquido-Liquido). El estudio experimental fue realizado en un tubo de vidrio borosilicato de 25,4 [mm] de diámetro interno y 12 [m] de longitud. El sensor está formado por una malla de alambre con dos planos de 8 x 8 hilos, llamado sensor de malla de alambre (WMS). Los experimentos fueron efectuados con dos viscosidades diferentes de aceite, una con 200 [cP] y otra de 60 [cP] a 860 [kg / m3]de densidad con el tubo posicionado en la horizontal y levemente inclinado a + 5 grados, para variar la viscosidad del aceite fue usado un intercambiador de calor. El patrón de flujo multifase analizado fue anular, estratificado y disperso. Las tomografías obtenidas por la WMS fueron comparadas con una cámara de alta velocidad para la validación cualitativa de los resultados. Se usaron doce modelos de permitividad eléctrica para el estudio del régimen del fluido presente

Capability of dual-modality electrical tomography for gas-oil-water three-phase pipeline flow visualisation

Numerous dual-modality tomography systems have previously been studied for multiphase flow characterisation, however, the capability of the majority of these systems was only demonstrated under limited flow regime conditions, such as stratified flow and slug flow. This paper reports a dual-modality electrical tomography for visualisation of industrial-scale, horizontal gas-oil-water three-phase flows. Experimental conditions include water-to-liquid ratio (WLR) from 0% to 100% in parallel with gas volume fractions (GVF) from 0% to 100%, which produced a variety of flow patterns, typically stratified flow, slug flow, plug flow, bubbly flow, and annular flow. A commercial dual-modality electrical tomographic system was utilised to carry out the measurement. A threshold-based data fusion method was also deployed for the fusion of oil-continuous and water-continuous data to provide full three phase images. The tomography visualisation is validated against optical photographs derived from a high-speed video logger located one diameter upstream of the device. The results demonstrate that a subcomponent of the dual modality sensor, an electrical resistance tomography (ERT) system, is able to visualise water continuous flow with WLR higher than 40%, providing good agreement with previous reports. The remaining subcomponent, the electrical capacitance tomography (ECT) system, is able to provide stable measurement during WLR from 0% to 90%, which is far beyond initial expectations and previous findings. Mean concentrations measured with the dual-modality system reveal the potential capability of the tomography system for phase fraction measurement. The visualisation results with the advanced data fusion method and mean concentration measurement verify the capability of the system in the application of gas-oil-water flow characterisation

A Data Fusion and Visualisation Platform for Multi-Phase Flow by Electrical Tomography

Electrical tomography, e.g. electrical resistance tomography (ERT) and electrical capacitance tomography (ECT), has been successfully applied to many industries for measuring and visualising multiphase flow. This research aims to investigate the data fusion and visualisation technologies with electrical tomography as the key data processing tools of a platform for multiphase flow characterisation. Gas-oil-water flow is a common flow in the gas and oil industries but still presents challenges in understanding its complex dynamics. This research systematically studied the data fusion and visualisation technologies using dual-modality electrical tomography (ERT-ECT). Based on a general framework, two data fusion methods, namely threshold and fuzzy logic with decision tree, were developed to quantify and qualify the flow. The experimental results illustrated the feasibility of the methods integrated with the framework to visualise and measure flows in six typical common flow regimes, including stratified, wavy stratified, slug, plug, annular, and bubble flow. In addition, the performance of ERT-ECT was also evaluated. A 3D visualisation approach, namely Bubble Mapping, was proposed to transform concentration distribution to individual bubbles. With a bubble-based lookup table and enhanced isosurface algorithms, the approach overcomes the limits of the conventional concentration tomograms in visualisation of bubbles with sharp boundaries between gas and liquid, providing sophisticated flow dynamic information. The experiments proved that Bubble Mapping is able to visualise typical flow regimes in different pipeline orientations. Two sensing methods were proposed, namely asymmetrical sensing and imaging (ASI) and regional imaging with limited measurement (RILM), to improve the precision of the velocity profile derived from the cross-correlation method by enhancing ERT sensing speed, which is particularly helpful for industrial flows that their disperse phase velocity is very high, e.g. 20 m/s of the gas phase. It is expected that the outcome of this study will significantly move electrical tomography for multiphase flow applications beyond its current challenges in both quantification and qualification