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Title: Tomographic flow measurement by combining component distribution and velocity profile measurements in 2-phase oil/gas flows
Author: Hayes, D. G.
ISNI:       0000 0004 2674 0461
Awarding Body: The University of Manchester
Current Institution: University of Manchester
Date of Award: 1994
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This thesis describes the development of a novel tomographic imaging system which can measure the concentration and velocity profiles in two-phase oil/gas flows. Two-phase flow measurement is a problem of great strategic and commercial importance to the oil industry. For example, an oilwell seldom produces just oil; there is often a significant quantity of gas and/or water present and it is very important to know how much of each is being produced. Unfortunately, this turns out to be a very demanding: task, particularly when the components have significantly different densities as in oil/gas flows. The fundamental problem with oil/gas flow measurement is that the individual components can arrange themselves in many different ways. This results in many possible concentration and velocity distributions, which in turn, render conventional flow measurement techniques inadequate. The tomographic system overcomes these problems by explicitly deriving the component distributions at two adjacent planes along a pipeline. These two images of the component distributions are then cross correlated on a pixel-by-pixel basis to obtain the velocity profile of the gaseous component. Multiplying the component concentration and velocity profiles yields a measure of the volumetric gas flow rate. The component distributions are obtained using two tomographic capacitance imaging systems. The problems caused by their interference have been examined in detail and this includes extensive electrostatic simulation studies. The field interactions are shown to affect the effective distance between the sensors and this varies with radial position, resulting in an effective separation profile". Numerous component distribution and velocity profile measurements are presented which were obtained from a 3" multi-phase flow loop, with superficial oil velocities ranging from 0.1m/s to 0.8m/s. and superficial gas velocities ranging from 0.05m/s to 0.5m/s. Void fractions range from 5% to 55%. The system is based on a combination of transputer and digital signal processor hardware and can reconstruct images at 180 frames per second. Techniques for real-time image correlation are examined and these, in combination with a number of suggestions for future work, will facilitate the development of a novel, real-time, multi-phase flow measurement system
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available