Development Of A Multiphase Composition Measurement

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Development Of A Multiphase Composition Measurement

Transcript Of Development Of A Multiphase Composition Measurement

Development Of A Multiphase Composition Measurement Method By Using Capacitive Sensor
Array
by c Javier Ortiz Castro A Dissertation submitted to the School of Graduate Studies in partial fulfillment of the requirements for the degree of
PhD Faculty of Engineering and Applied Science

St. John’s

Research advisor: Dr. Vlastimil Masek Memorial University of Newfoundland
October 2015

Newfoundland

Abstract
Multiphase flow, a flow of two or more liquid/gas components, is present in many industries. One of the challenges is to measure accurately the volumetric/mass ratio of each component against the total volume/mass. In the oil and gas industry, this kind of measurement is performed on a regular basis. Since the early 1980s, many methods have been proposed for multiphase flow measurement and some are commercially available today. However, these sensors often depend on a separator to isolate each phase, or use a homogenizer/mixer to achieve consistent solutions, or employ GammaRay radiation provided by a nuclear source. The approach used in this research is to combine a sensor with an integrated cyclonic stratifier that transforms diverse flow regimes of multiphase flow into a channel flow regime. The sensor employs a relatively simple capacitive sensor array and allows for accurate measurements of phase fractions in real time. The system is also capable of compensating for drift in parameters such as permittivity, often caused by a changed chemical composition, e.g. the level of sulphur in the oil, the salinity of water, or due to variable temperature.
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Table of Contents

Abstract

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Table of Contents

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List of Tables

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List of Figures

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1 Introduction

1

1.1 Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.2 Organization of This Work . . . . . . . . . . . . . . . . . . . . . . . . 6

2 Multiphase Flow Measurements

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2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2.2 Types of Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2.3 Flow Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2.4 MPFM Measurement Approaches . . . . . . . . . . . . . . . . . . . . 13

2.4.1 Velocity Measurements . . . . . . . . . . . . . . . . . . . . . . 14

2.4.2 Component Fraction Measurement . . . . . . . . . . . . . . . 19

2.4.2.1 Electrical Impedance Method . . . . . . . . . . . . . 19

2.4.2.2 Gamma Ray . . . . . . . . . . . . . . . . . . . . . . 24

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2.4.2.3 Other Techniques . . . . . . . . . . . . . . . . . . . . 25 2.5 Two Phase Liquid Separation . . . . . . . . . . . . . . . . . . . . . . 27 2.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

3 Proposed Measurement Method

31

3.1 Stratified Flow Regime in a Rectangular Measurement Chamber . . . 31

3.1.1 Linear Independence of the Measurement . . . . . . . . . . . . 32

3.1.2 Parallel-Capacitor Configuration . . . . . . . . . . . . . . . . . 33

3.1.3 Series-Capacitor Configuration . . . . . . . . . . . . . . . . . . 34

3.1.4 Summary of Currently in use Methods and Proposed Electrode

Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

3.2 Sensor Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

3.2.1 Parallel Plate Electrode Model . . . . . . . . . . . . . . . . . . 37

3.2.2 Concentric Cylindrical Electrode Model . . . . . . . . . . . . . 43

3.3 FEA Analysis of a Prototype . . . . . . . . . . . . . . . . . . . . . . 48

3.3.1 Measurement Process Analysis . . . . . . . . . . . . . . . . . . 50

3.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

4 Dielectric Measurement

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4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

4.2 Apparatus for the measurement of dielectric constant . . . . . . . . . 55

4.3 Experiment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

4.4 FEM approach to the ‘negative’ permittivity problem . . . . . . . . . 64

4.5 Experimental resolution of the ‘negative’ permittivity . . . . . . . . . 67

4.6 Incomplete Separation Study . . . . . . . . . . . . . . . . . . . . . . . 73

4.6.1 Oil-in-water and water-in-oil differences . . . . . . . . . . . . 74

4.6.2 Permittivity transitional buffer effects . . . . . . . . . . . . . . 76

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4.7 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

5 Design of a Compact Multiphase Flow Loop

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5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

5.2 Multiphase Separator . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

5.3 Positive Displacement Pumps . . . . . . . . . . . . . . . . . . . . . . 86

5.4 Data Acquisition and Interfacing . . . . . . . . . . . . . . . . . . . . 87

5.5 Frequency Measurement . . . . . . . . . . . . . . . . . . . . . . . . . 89

5.6 Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

5.7 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

6 Experimental Verification

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6.1 Prototype #1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

6.1.1 Capacitive Divider/Bridge . . . . . . . . . . . . . . . . . . . . 94

6.1.2 Frequency Tests . . . . . . . . . . . . . . . . . . . . . . . . . . 97

6.1.3 Temperature Test . . . . . . . . . . . . . . . . . . . . . . . . . 98

6.1.3.1 Air Test . . . . . . . . . . . . . . . . . . . . . . . . . 99

6.1.3.2 Air Pump Characterization . . . . . . . . . . . . . . 99

6.1.3.3 Air Pump Test Results . . . . . . . . . . . . . . . . . 102

6.2 Capacitive Static Tests . . . . . . . . . . . . . . . . . . . . . . . . . . 104

6.2.1 Capacitive Test With a Single Coil . . . . . . . . . . . . . . . 104

6.2.2 Capacitive Static Test With Two Coils . . . . . . . . . . . . . 105

6.2.3 Capacitive Static Test With Two Coils and a Metal Shield . . 107

6.3 Prototype #2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

6.3.1 Hydrocyclone . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

6.3.1.1 Capacitive Test . . . . . . . . . . . . . . . . . . . . . 108

6.3.2 Signal Attenuation Study . . . . . . . . . . . . . . . . . . . . 111

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6.3.3 Automated Attenuation Test . . . . . . . . . . . . . . . . . . . 112 6.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115

7 Flow separation study

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7.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

7.2 Flow visualization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

7.2.1 Electrolytic Flow Visualization . . . . . . . . . . . . . . . . . 117

7.2.2 Experimental Setup . . . . . . . . . . . . . . . . . . . . . . . . 118

7.3 CFD simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122

7.4 Turbo-cyclone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124

7.5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127

8 Conclusion And Future Work

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8.1 Future Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134

9 Publications

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References

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Bibliography

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A Flow Loop

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A.1 Gear Pumps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146

A.2 Data Acquisition Card . . . . . . . . . . . . . . . . . . . . . . . . . . 147

B Water and Oil Permittivities

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B.1 Water Permittivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148

B.2 Oil Permittivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153

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List of Tables
4.1 Apparatus dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . 56 4.2 Glass wall - outer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 4.3 Air dielectric . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 4.4 Water dielectric . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 4.5 Oil dielectric . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 4.6 Glass wall permittivity . . . . . . . . . . . . . . . . . . . . . . . . . . 63 4.7 Air, Water, Oil capacitances and permittivities . . . . . . . . . . . . . 63 4.8 Original configuration model from Figure 4.2 . . . . . . . . . . . . . . 65 4.9 Modified configuration model from Figure 4.8 . . . . . . . . . . . . . 66 4.10 Glass wall capacitance C3 - inside . . . . . . . . . . . . . . . . . . . . 68 4.11 Glass wall capacitance C1 - outside . . . . . . . . . . . . . . . . . . . 69 4.12 Water dielectric capacitance C2 and permittivity . . . . . . . . . . . 70 4.13 Capacitance data for determining saline water permittivity . . . . . . 71 4.14 Saline water capacitance . . . . . . . . . . . . . . . . . . . . . . . . . 72 4.15 50% mixture separation in time . . . . . . . . . . . . . . . . . . . . . 74 4.16 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
6.1 Coil Inductance Values . . . . . . . . . . . . . . . . . . . . . . . . . . 112
A.1 Lead Wire Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . 146
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A.2 Jumper Configuration for DAC0 . . . . . . . . . . . . . . . . . . . . . 147 A.3 Jumper Configuration for DAC1 . . . . . . . . . . . . . . . . . . . . . 147 B.1 Cole-Cole Parameters for the Spectra of the Crude Oils B1 and B2 . 153
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List of Figures
1.1 Conventional offshore component fraction measurements [1]. . . . . . 1 1.2 Individual offshore component fraction measurements [1]. . . . . . . . 3
2.1 Flow regimes in vertical pipes . . . . . . . . . . . . . . . . . . . . . . 10 2.2 Flow regimes for liquid and gas in horizontal pipes . . . . . . . . . . . 11 2.3 Liquid-liquid flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.4 Venturi flowmeter . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.5 Ultrasonic flowmeter . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2.6 Positive displacement flowmeter . . . . . . . . . . . . . . . . . . . . . 16 2.7 Cross correlation method [3] . . . . . . . . . . . . . . . . . . . . . . . 16 2.8 Electromagnetic flowmeter diagram . . . . . . . . . . . . . . . . . . . 17 2.9 Capacitance principle [5] . . . . . . . . . . . . . . . . . . . . . . . . . 20 2.10 Conductance principle [5] . . . . . . . . . . . . . . . . . . . . . . . . 21 2.11 Electrode configuration for capacitive sensors [21] . . . . . . . . . . . 21 2.12 Equivalent capacitance circuits for different flow regimes [21]. . . . . . 22 2.13 Configurations of a two coaxial cylinder capacitor . . . . . . . . . . . 23 2.14 Gamma ray plot for different component fractional ratios.[1] . . . . . 24 2.15 Nonelectrode electromagnetic flowmeter . . . . . . . . . . . . . . . . . 27 2.16 Hydrocyclone operating principle . . . . . . . . . . . . . . . . . . . . 28 2.17 Hydrocyclone application for sand filtering . . . . . . . . . . . . . . . 29
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2.18 Turbocyclone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
3.1 Capacitive level measurement - parallel configuration . . . . . . . . . 32 3.2 Series capacitor configuration level measurement . . . . . . . . . . . . 34 3.3 Hydrocyclone instrumented with three pairs of electrodes. . . . . . . 35 3.4 A cyclonic capacitive sensor with parallel plate electrodes. Ri Desig-
nates the outer radii, whereas ri designates the radii of the inner core, and ρi is the radii of the oil/water interfases. . . . . . . . . . . . . . . 38 3.5 Ci = Ci(α%), i = 1, 2, ε1 = 2.0, r2 = 8 × r1 . . . . . . . . . . . . . 40 3.6 Ci = Ci(α%, ε1), i = 1, 2, r2 = 8 × r1 . . . . . . . . . . . . . . . . 41 3.7 Linear disparity as r2 increases against r1. . . . . . . . . . . . . . . . 41 3.8 Model 1. The intersection angles for different values of α. . . . . . . . 42 3.9 Model 1. The intersection angles as a function of composition and ε1. 42 3.10 A cyclonic capacitive sensor with coaxial plate electrodes . . . . . . . 44 3.11 Ci = Ci(α%), i = 1, 2, ε1 = 2.0, r2 = 8 × r1 . . . . . . . . . . . . . 46 3.12 Linear disparity as r2 increases against r1. . . . . . . . . . . . . . . . 46 3.13 Model 2. Intersection angles for different values of α. . . . . . . . . . 47 3.14 Model 2. The intersection angles as a function of composition and ε1. 47 3.15 Configuration of the internal cone for a three electrode sensor . . . . 48 3.16 Capacitance for different composition and oil permittivities when εw = 80. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 3.17 Intersection angles in the plane ε1 − α . . . . . . . . . . . . . . . . . 51 3.18 Intersection angles as a function of composition for different values of ε1. 51 3.19 Surfaces with the same capacitance . . . . . . . . . . . . . . . . . . . 52 3.20 Lines with the same composition from different electrodes . . . . . . . 53
4.1 Experimental apparatus . . . . . . . . . . . . . . . . . . . . . . . . . 56
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CompositionFunctionRadiiMeasurementIntersection Angles