UNIVERSITI PUTRA MALAYSIA

THEORETICAL ANALYSIS ON THE ELECTRICAL PERFORMANCE OF

LONG COAXIAL CABLE AT DIFFERENT TEMPERATURE

DEVARAJ KANISIN

FK 2006 109

THEORETICAL ANALYSIS ON THE ELECTRICAL PERFORMANCE OF

LONG COAXIAL CABLE AT DIFFERENT TEMPERATURE

By

DEVARAJ KANISIN

Thesis Submitted to the School of Graduate Studies, Universiti Putra Malaysia, in Fulfilment of the Requirement for the Degree of Master of Science

November 2006

ii

DEDICATION

I dedicate this dissertation to my parents.

iii

Abstract of thesis presented to the Senate of Universiti Putra Malaysia in fulfilment of the requirement for the degree of Master of Science

THEORETICAL ANALYSIS ON THE ELECTRICAL PERFORMANCE OF LONG COAXIAL CABLE AT DIFFERENT TEMPERATURE

By

DEVARAJ KANISIN

November 2006

Chairman : Tang Sai Hong, PhD

Faculty : Engineering

Long coaxial cables are widely used in telecommunication industry and, in oil and gas

industry. The telecommunication industry mainly uses these cables for

telecommunication between island, countries, etc. While in Oil and Gas Industry, the

long coaxial cable plays a central role in production and well maintenance services. The

long coaxial cable is attached with the down-hole monitoring equipment and travels to

the well of 6 to 7 kilometres depth without repeaters. It is used to supply power to down-

hole equipment and also provide communication link with the computer located at the

oil rig or ship. During the transmission period, the long coaxial cable is often subjected

to temperature differences and external noise interference. Both elements can be

considered as interrelated with address to the degradation on the performance of the long

coaxial cable. Therefore, the aim of the research is to investigate the performance of the

long coaxial cable. The objectives are to analyze and evaluate the performance of the

iv

long coaxial cable corresponding to temperature differences, and also to develop and

analyze the thermal transfer analysis for long coaxial cable. The methodology used for

the research consists of five main stages such as mathematical analysis, designing long

coaxial channel model as FIR filter, theoretical analysis, practical analysis and thermal

transfer modeling.

The study and the investigation were conducted on the MATLAB by designing a long

coaxial channel model. The designed long coaxial model were experimented and

analyzed for various length (eg:- 1 km, 3 km, 5 km, 6.096 km which equivalent to 20k

feet, 8 km and 10km), various frequencies (eg: 10kHz, 50kHz and 100kHz) and various

temperatures (eg: 20°C and 150°C). The experiment was repeated by considering the

skin effect. Finally, the thermal transfer formula for the long coaxial cable is formulated

and the same experiment above was repeated. In overall, the analysis shows the

developed long coaxial channel model has the ability to evaluate and analyze the

performance of any long coaxial cable at different temperatures leading to thermal

transfer. Conclusively, four internal factors or criteria leading to thermal transfer have

been identified, which plays the major role on the performance of the long coaxial cable

at different temperatures. They are frequency, temperature, skin effect and length of the

long coaxial cable.

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Abstrak tesis yang dikemukakan kepada Senat Universiti Putra Malaysia sebagai memenuhi keperluan untuk ijazah Master Sains

ANALISIS TEORI TERHADAP PRESTASI KABEL PANJANG ‘COAXIAL’ PADA SUHU YANG BERLAINAN

Oleh

DEVARAJ KANISIN

November 2006

Pengerusi : Tang Sai Hong, PhD

Fakulti : Engineering

Kabel panjang ‘coaxial’ digunakan secara meluas di dalam industri telekomunikasi serta

di dalam industri petroleum dan gas asli. Bagi industri telekomunikasi, penggunaan

kabel tersebut adalah untuk menghubungkan antara pulau, negara dan sebagainya.

Manakala bagi industri minyak dan gas pula, kabel panjang ‘coaxial’ memainkan

peranan yang penting untuk produksi dan servis penyelenggaraan. Kabel panjang

‘coaxial’ disambungkan dengan peralatan pemantauan ‘down-hole” dan boleh mencecah

jarak sehingga 6 ke 7 kilometer ke dalam telaga tanpa pengulang, ‘repeater’. Ia

digunakan untuk menyediakan perhubungan telekomunikasi dengan komputer yang

terletak di atas pelantar minyak atau kapal. Semasa proses transmisi, kabel panjang

‘coaxial’ selalu dihubungkaitkan dengan perubahan suhu dan interferens bunyi luaran.

Kedua-duanya boleh dikaitkan di antara satu sama lain dengan degradasi prestasi kabel

dasar laut ‘coaxial’ tersebut. Oleh yang demikian, kajian lebih difokuskan kepada

vi

penyelidikan di atas prestasi kabel panajang ‘coaxial’. Objektif kajian ini adalah untuk

menganalisa prestasi kabel panjang ‘coaxial’ berhubungkait dengan perubahan suhu dan

juga mereka berserta menganalisa pemindahan terma melalui kabel panjang ‘coaxial’.

Metodologi yang digunakan merangkumi 5 tahap iaitu analisa matematik, mereka kabel

panjang ‘coaxial’ sebagai FIR filter, analisa teori, analisa praktikal dan model

pemindahan terma.

Pengkajian dan penyelidikan terhadap situasi terbabit dilakukan dengan menggunakan

MATLAB dengan cara mereka-cipta model kabel panjang ’coaxial’. Model rekaan ini

dianalisa dengan menggunakan beberapa parameter seperti panjang kabel (contoh: 1km,

3km, 5km, 6.096km bersamaan dengan 20k kaki, 8km dan 10km), frekuensi ( contoh:

10kHz, 50kHz dan 100kHz) dan suhu (contoh: 20oC dan 150oC). Eksperimen ini

diulang beberapa kali untuk mempertimbangkan ‘skin effect’. Akhirnya, formula

pemindahan terma bagi kabel dasar laut ‘coaxial’ direka dan eksperimen tadi diulang.

Secara keseluruhannya, kajian dan hasil penyelidikan menunjukkan model panjang laut

‘coaxial’ ini mampu menilai dan menganalisa pemindahan terma untuk pelbagai jenis

kabel panjang ‘coaxial’. Oleh yang demikian, terdapat empat faktor atau kriteria yang

disabitkan dengan pemindahan terma telah dikenal pasti, yang mana ia memainkan

peranan yang penting di dalam prestasi kabel panajang ‘coaxial’. Faktor-faktor tersebut

adalah frekuensi, suhu, ‘skin-effect’ dan panjang kabel panjang ‘coaxial’.

vii

ACKNOWLEDGEMENTS

I would like to begin my thanking to my parents for giving me the courage and strength I

needed to complete my research. Without their everlasting love and support I would

have not reached my goal.

Now, I would like to express my deepest gratitude and appreciation to my supervisor, Dr.

Tang Sai Hong for his patient guidance, encouragement, cooperation, full support and

close consultation throughout the research and thesis writing. His guidance and advice

throughout this research has been very inspiring and indispensable for the success of my

research.

In addition, special thanks are due to Assoc. Prof. Dr. Napsiah Ismail for her invaluable

comments, guidance, consultation and support throughout the research.

Last but not least, I would like to thank all my friends who helped me throughout my

research and thesis writing, particularly Biswajeet Pradhan and A.S. Lakshimy.

Finally, I would like to express my thanks and gratitude to all the kind hearts who have

contributed directly or indirectly to the success of my research.

viii

I certify that an Examination Committee met on 17th November 2006 to conduct the final examination of Devaraj Kanisin on his Master degree thesis entitled “Theoretical Analysis on the Electrical Performance of Long Coaxial Cable at Different Temperature” in accordance with “Universiti Pertanian Malaysia (Higher Degree) Act 1980 and Universiti Pertanian Malaysia (Higher Degree) Regulations 1981. The committee recommends that the candidate be awarded the relevant degree. Members of the Examination Committee are as follows:

Yusof Ismail, PhD Associate Professor Faculty of Engineering Universiti Putra Malaysia (Chairman) Wong Shaw Voon, PhD Associate Professor Faculty of Engineering Universiti Putra Malaysia (Internal Examiner) Megat Mohamad Hamdan Megat Ahmad, PhD Associate Professor Faculty of Engineering Universiti Putra Malaysia (Internal Examiner) Ahmad Kamal Ariffin Mohd. Ihsan, PhD Professor Faculty of Engineering Universiti Kebangsaan Malaysia (External Examiner) _____________________________

HASANAH MOHD. GHAZALI, PhD Professor / Deputy Dean School of Graduate Studies Universiti Putra Malaysia Date: 27 APRIL 2007

This thesis submitted to the Senate of Universiti Putra Malaysia and has been accepted as fulfilment of the requirement for the degree of Master of Science. The members of the Supervisory Committee are as follows: Tang Sai Hong, PhD Lecturer Faculty of Engineering Universiti Putra Malaysia (Chairman) Napsiah Ismail, PhD Associate Professor Faculty of Engineering Universiti Putra Malaysia (Member)

AINI IDERIS, PhD Professor/Dean School of Graduate Studies Universiti Putra Malaysia Date: 10 MAY 2007

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DECLARATION

I hereby declare that the thesis is based on my original work except for quotations and citations which have been duly acknowledged. I also declare that it has not been previously or concurrently submitted for any other degree at UPM or other institutions.

DEVARAJ KANISIN Date: 6 APRIL 2007

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TABLE OF CONTENTS

Page

DEDICATION iiABSTRACT iiiABSTRAK vACKNOWLEDGEMENTS viiAPPROVAL viiiDECLARATION xLIST OF TABLES xivLIST OF FIGURES xvi CHAPTER

1 INTRODUCTION 1.1 Preface 1.1 1.2 Problem Statement 1.1 1.3 Research Aim and Objectives 1.4 1.4 Significance of the Research 1.5 1.5 Organization of the Chapters 1.5

2 LITERATURE REVIEW 2.1 Introduction 2.1 2.2 Power Cable Evolution 2.3 2.3 Communication Cable Evolution 2.4 2.4 Subsea Cables 2.5 2.4.1 Types of Subsea Cables 2.9 2.4.2 The Usage of Cables 2.15 2.5 Analysis and Performance of the Cable 2.17 2.5.1 Analysis of Transmission Line Theory 2.17 2.5.2 Performance of the Cables at Different

Temperature 2.19

2.6 Energy Transfer 2.24 2.7 Analysis of Energy Transfer on Cables 2.28 2.7.1 Energy Transfer on Cables 2.28 2.7.2 Internal Parameter Leading to Energy Transfer

on the Cables 2.33

2.7.3 Numerical Analysis and Stability Studies Associated with Energy Transfer

2.35

2.8 Conclusion 2.38 3 METHODOLOGY

3.1 Introduction 3.1 3.2 Design Assumptions 3.3

xii

4 MATHEMATICAL ANALYSIS 4.1 Introduction 4.1 4.2 Primary Parameter of Long Coaxial Cable 4.2 4.2.1 The Equivalent Circuit of Long Coaxial Cable 4.3 4.2.2 Analysis of the Equivalent Circuit 4.4 4.2.3 Steady-State Sinusoidal Solution for Voltage

and Current 4.6

4.3 Secondary Parameter of Long Coaxial Cable 4.10 4.3.1 The Characteristic Impedance, Zo of the Long

Coaxial Cable 4.11

4.3.2 The Complex Propagation Constant, γ 4.11 4.3.3 Consider the Attenuation Coefficient, α 4.12 4.3.4 Consider the Phase Constant, β 4.13 4.3.5 Velocity of Propagation 4.16 4.4 Relationship between the Primary and Secondary

Parameters 4.17

5 MODELLING LONG COAXIAL CHANNEL MODEL

5.1 Introduction 5.1 5.2 Designing Long Coaxial Channel Model as FIR Filter 5.2 5.2.1 Designing the Long Coaxial Channel Model on

MATLAB 5.3

5.2.2 Impulse Response 5.3 5.2.3 FIR Filter 5.4 5.3 Analysis without Skin Effect 5.6

5.3.1 Magnitude Response and Phase Response 5.7 5.4 Analysis with Skin Effect 5.8 5.4.1 Skin Effect 5.9 5.5 Energy Transfer Model 5.12

5.5.1 Formulate Energy Transfer Equation 5.13 6 RESULTS AND DISCUSSION

6.1 Introduction 6.1 6.2 Analysis without Skin Effect 6.2 6.3 Analysis with Skin Effect 6.9

6.3.1 Performance Comparison (Without Skin Effect versus With Skin Effect)

6.12

6.4 Energy Transfer Model 6.15 6.4.1 Energy Transfer Analysis for Long Coaxial

Cable without Skin Effect 6.19

6.4.2 Energy Transfer Analysis for Long Coaxial Cable with Skin Effect

6.23

6.4.3 Energy Transfer Comparison (Without Skin 6.27

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Effect versus With Skin Effect) 7 CONCLUSION AND FUTURE WORK

7.1 Introduction 7.1 7.2 Conclusion 7.1 7.3 Major Contribution 7.3 7.4 Limitation of the Research 7.4 7.5 Future Work 7.5 7.5.1 Recommendation for Cable Manufacturers 7.5 7.5.2 Suggestion for Improving the System 7.6 REFERENCES R.1APPENDICES A.1BIODATA OF THE AUTHOR

B.1

LIST OF TABLES

Table

Page

3.1

Long Coaxial Cable Primary Parameters 3.4

4.1 Relationship of Primary and Secondary Parameters of the Long Coaxial Cable

4.17

5.1 Skin Effect Ratio (Source: Chapter 16 Undersea Coaxial Communication Cables)

5.10

AC Resistances, R1 (at 20oC )

5.2a 5.10

AC Resistances, R2 (at 150oC)

5.2b 5.11

6.1a Magnitude Response and Phase Response for 1 km of Long Coaxial Cable

6.5

6.1b Magnitude Response and Phase Response for 3 km of Long Coaxial Cable

6.6

6.1c Magnitude Response and Phase Response for 5 km of Long Coaxial Cable

6.6

6.1d Magnitude Response and Phase Response for 6.096 km of Long Coaxial Cable

6.7

6.1e Magnitude Response and Phase Response for 8 km of Long Coaxial Cable

6.7

6.1f Magnitude Response and Phase Response for 10 km of Long Coaxial Cable

6.8

6.2a Magnitude Response and Phase Response for 1 km Long Coaxial Cable

6.9

6.2b Magnitude Response and Phase Response for 3 km Long Coaxial Cable

6.10

6.2c Magnitude Response and Phase Response for 5 km Long Coaxial Cable

6.10

6.2d

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Magnitude Response and Phase Response for 6.069 km of Long Coaxial Cable

6.11

xv

6.2e Magnitude Response and Phase Response for 8 km of Long Coaxial Cable

6.11

6.2f Magnitude Response and Phase Response for 10 km of Long Coaxial Cable

6.12

6.3 Energy Transfer Analysis of the Long Coaxial Cable (10km at 100kHz)

6.18

6.4a Energy Transfer Analysis of the Long Coaxial Cable for Frequency 10kHz

6.20

6.4b Energy Transfer Analysis of the Long Coaxial Cable for Frequency 50kHz

6.21

6.4c Energy Transfer Analysis of the Long Coaxial Cable for Frequency 100kHz

6.22

6.5a Energy Transfer Analysis of the Long Coaxial Cable for Frequency 10kHz

6.24

6.5b Energy Transfer Analysis of the Long Coaxial Cable for Frequency 50kHz

6.25

6.5c Energy Transfer Analysis of the Long Coaxial Cable for Frequency 100kHz

6.26

LIST OF FIGURES

Figure

Page

1.1 Long Coaxial Cable and Offshore Environment

1.2

2.1 Long Coaxial Cable (Courtesy by DUCO Ltd)

2.8

2.2 Equivalent Lumped Parameter Circuit

2.17

3.1 Methodology Flowchart

3.1

3.2 Long Coaxial Cable

3.4

4.1 Primary Parameter of Long Coaxial Cable

4.2

4.2 The Equivalent Circuit of Long Coaxial Cable

4.3

4.3 Analysis of the Equivalent Circuit

4.4

4.4 4.12Attenuation Coefficient, α

4.5 4.13Phase Constant, β

4.6 Velocity, u 4.16

5.1 Flowchart for Designing Long Coaxial Channel Model as FIR Filter 5.2

5.2 Impulse Response at Frequency 10kHz for 10km Long Coaxial Cable

5.4

5.3 Filtered Impulse Response at Frequency 10kHz for 10km Long Coaxial Cable

5.6

6.1 Magnitude Response and Phase Response (1km)

6.5

6.2 Magnitude Response and Phase Response (10km at 50kHz)

6.13

6.3 Magnitude Response and Phase Response (10km at 100kHz) 6.13

6.4 Energy Transfer on the Long Cable (10km at 100kHz) 6.18

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CHAPTER 1

INTRODUCTION

1.1 Preface

This chapter recalls the scientific environment of this thesis with a non-exhaustive

enumeration of prior work and existing solutions in the major areas covered. It

highlights the research aims, objectives, scopes and organization of the thesis. Long

coaxial cables are widely used in telecommunication industry and, oil and gas industry.

The telecommunication industry mainly uses these long coaxial cables for

telecommunication between islands and countries. While, the oil and gas industry use

these long coaxial cables on the oil rig or ship to supply power and communications to

monitoring equipment in the subsea environment and down-hole wells. This type of

long coaxial cable is also known as wireline in oil and gas industry. This research will

emphasize and focus on the oil and gas industry. In addition, the research will evaluate

and analyze the performance of the long coaxial cable at different temperature leading to

energy transfer.

1.2 Problem Statement

In Oil and Gas Industry, the long coaxial cable plays a central role in production and

well maintenance services. This cable is also known as wireline cable. The current well

known cable providers are The Expro Group and Schlumberger (The Expro Group Ltd,

2006 and Schlumberger Ltd, 2006). This cable is attached with the down-hole

monitoring equipment and travels to the well of 6 to 7 kilometres depth without

repeaters as illustrated on the Figure1.1.

Figure 1.1: Long Coaxial Cable and Offshore Environment

1.2

1.3

This cable is used to supply power to down-hole equipment and also provide

communication link with the computer located at the oil rig or ship. The down-hole

monitoring equipment is assigned to measure the temperature and pressure of the well.

In addition, it is also used to scan and detect the cracks on the surface of the casing by

using gamma-ray technology. This information will be transmitted via the long coaxial

cable to the computer at the oil rig or ship. During the transmission period, the long

coaxial cable is often subjected to temperature differences and external noise

interference (Richardson, 2001). Both elements can be considered as interrelated among

them with address to the degradation on the performance of the long coaxial cable

(Kanisin, 2002).

Therefore, this research will be focused on investigating the performance of the long

coaxial cable corresponding to temperature differences. It will be emphasized on finding

the possible factors or criteria that degrade the performance of long coaxial cable.

These factors are determined so that, the performance of the long coaxial cable can be

evaluated and improved. Furthermore, this finding has not been done by any researcher

so far. In addition, the research uses a new concept of evaluating the performance by

using temperature differences which lead to energy transfer on the long coaxial cable.

Firstly, the long coaxial cable is analyzed using transmission line theory. Then, a

channel model is developed to evaluate the performance corresponding to temperature

differences and determine the factors lead to energy transfer. Finally, the energy transfer

formula is formulated and the energy transfer analysis is performed. This new concept

1.4

above basically, has combined the electrical and electronic technology with computer

software technology to solve a mechanical problem. Conclusively, this concept has

merged and integrates the technologies above together to produce better performance of

the long coaxial cable.

In overall, this research will contribute towards the process of enhancement and further

development of the long coaxial cable focusing on the performance and emphasizing on

the possible factors or criteria corresponding to temperature differences leading to

energy transfer on the long coaxial cable. The energy is referred to the electrical energy

which has been transferred mainly to heat energy.

1.3 Research Aim and Objectives

The aim of this research is to investigate the performance of the long coaxial cable. The

objectives are:

i. To analyze and evaluate the performance of the long coaxial cable corresponding

to temperature differences.

ii. To develop and analyze the energy transfer analysis for the long coaxial cable.

1.5

1.4 Significance of the Research

The primary motivation for this research stems from finding the possible factors or

criteria corresponding to temperature differences that lead to energy transfer on the long

coaxial cable. These factors are determined so that, the performance of the long coaxial

cable can be evaluated and improved. Furthermore, the energy transfer on the long

coaxial cable can be minimized based on the scenario by manipulating the factors values

in order to get the best performance of the long coaxial cable. In addition, the research

uses a new concept of evaluating the energy transfer on the long coaxial cable.

1.5 Organization of the Chapters

The chapters of the thesis are presented and organized as below:-

a) Chapter 1 recalls the scientific environment of this thesis with a non-exhaustive

enumeration of prior work and existing solutions in the major areas covered. It

highlights the research aims, objectives, scopes and organization of the thesis.

b) Chapter 2 describes brief reviews on the cables. It also covers some of the

previous research on different types of cable. In addition, the chapter also

emphasized on the latest findings related to the research.

1.6

c) Chapter 3 describes about the methodology used for the research. It consists of

five main stages such as mathematical analysis, designing long coaxial channel

model as FIR filter, analysis without skin effect, analysis with skin effect and

energy transfer model.

d) Chapter 4 describes the mathematical analysis of the research. The primary and

the secondary parameter of the long coaxial cable have been analyzed. The

transmission line theory derived was based on the long coaxial cable structure.

The derived theories were used to design the long channel model on MATLAB.

e) Chapter 5 describes about the modelling of the long coaxial channel model. The

long coaxial cable is unlike a filter circuit, which is a “lumped network” as

individual components appear as discrete items. The long coaxial cable can be

represented as a digital filter. Therefore, a channel model of a long coaxial cable

was developed in the form of a FIR Filter using MATLAB in order to analyze

and evaluate the performance corresponding to temperature different which leads

to energy transfer on the long coaxial cable.

f) Chapter 6 describes the results and discussion part of the thesis. It is divided to

three important stages. Below are the summary of each stages:-

i. Analysis without skin effect:- To experiment and analyze the long

coaxial cable on MATLAB for various length (e.g: 1 km, 3 km, 5

1.7

km, 6.096 km which equivalent to 20k feet, 8 km and 10 km),

various frequencies (e.g: 10 kHz, 50 kHz and 100 kHz) and

various temperature (e.g: 20°C and 150°C).

Note: Three criteria have been identified, which plays the major

role on the performance of the long coaxial cable. They

are frequency, temperature and length of the long coaxial

cable.

ii. Analysis with skin effect:- To consider the skin effect on the long

coaxial cable and repeat the experiment and the analysis as on (i)

above.

Note: The performance of the long coaxial cable was good at

frequencies of 10 kHz to 20 kHz, but the skin effect of the

cable degraded the performance of the cable above 20kHz.

iii. Energy Transfer Model:- Develop and analyze the energy transfer

analysis for the long coaxial cable on MATLAB.

Note: In overall it shows that, heat generated degrades the

performance of the long coaxial cable. It shows that

factors such as higher frequency or longer cable or higher

temperature plays it role with the skin effect of the cable.

Therefore, it can be concluded that, all these factors plays

1.8

an important role on the performance leading to energy

transfer on the long coaxial cable.

g) Chapter 7 briefly summarizes and concludes the thesis, contribution of the

research and their implication for future research.