ANALYSIS OF GAS TRANSMISSION NETWORK OF BANGLADESH
A Thesis Submitted to the Department of Chemical Engineering In partial fulfillment of the requirements for the Degree of Master of Science in Engineering (Chemical)
By PRADIP CHANDRA MANDAL
1111111111111111111111111111111111 #96119#
DEPARTMENT OF CHEMICAL ENGINEERING BANGLADESH UNIVERSITY OF ENGINEERING AND TECHNOLOGY, DHAKA BANGLADESH FEBRUARY 2002 RECOMMENDATION OF THE BOARD OF EXAMINERS
The undersigned certify that they have read and recommended to the Department of Chemical Engineering, for acceptance, a thesis entitled Analysis of Gas Transmission Network of Bangladesh submitted by Pradip Chandra MandaI in partial fulfillment of the requirements for the degree of Master of Science in Chemical Engineering.
Chairman (Supervisor) 4~~: .... Dr. Edmond Gomes Professor Dept. of Petroleum and Mineral Resources Engg.
Member (Co-Supervisor): ~.Q,:-:,.~).(:,~ . Dr. A K. M. A Quader Professor Department of Chemical Engg.
Member: ~:~~.~ . Dr. Ijaz Hossain Professor and Head Department of Chemical Engineering BUET, Dhaka.
Member (External): ...... deG'~_ . Dr. AH.M. Shamsuddin Chief Geologist UNOCAL Bangladesh Ltd Lake View House No. :12, Road No. :137 Gulshan, Dhaka 1212.
Date: February 19,2002 ABSTRACT
The gas transmission pipelines in Bangladesh were initially planned and constructed targeting particular bulk consumers or potential load centers. In the early stage of the development of the gas sector, the grid system was possibly not visualized. But over the years the gas transmission system has expanded considerably and has become complicated.
The objective of the study is to perform gas transmission network analysis of Bangladesh. The study has been undertaken to simulate the present network system, identify its limitations and suggest remedial measures. This study would be useful to understand the performance of the present gas transmission system of Bangladesh. This study would also analyze the existing pipeline capacity and examine the level of capacity utilization.
The work was completed with the help of a commercial software, PIPES 1M-Net. After pressure matching at different load centers, manifold stations and branches, different scenarios were studied for future performance prediction. Finally, the scenarios were discussed and highlighted different important points through conclusion and recommendation. The simulated results will be helpful to identify the bottlenecks and to plan for future expansion of gas transmission system.
There are twenty-two gas fields in Bangladesh. But twelve producing gas fields can produce 1300 MMSCFD of gas from 53 gas wells. The study shows that Ashugonj metering station is the focal points of the National Gas Grid. Gas from the North-Eastern Gas Fields are being transported through the North-South pipeline to Ashuganj Manifold Station of GTCL from where it is further transmitted to Titas franchise area (TFA) and Bakhrabad franchise area (BFA) through Brahmaputra Basin pipe line and Ashuganj- Bakhrabad Transmission pipe lines. From Bakhrabad Gas Field, Bakhrabad-Chittagong Pipeline transports part of the required gas for Chittagong. The remaining gases for Chittagong is supplied from Salda, Meghna and Sangu gas fields. The results show that effective pipeline diameter of major transmission lines have decreased due to condensate accumulation. Hence pigging is necessary. Rashidpur- Ashugonj loop line is essential to supply growing gas demand. It will increase the . capacity of the North-South pipeline by 456 MMSCFD. To meet the future gas demand of the Western region, the results show that another loop line is necessary from Rashidpur-Ashugonj loop line to Dhanua. It will increase the supply of Ashugonj-Elenga pipeline by 175 MMSCFD. Analysis also shows that it is a better option to install a compressor station at Bakhrabad to transmit the low-pressure gas of the field through the
high-pressure pipeline.
ii ACKNOWLEDGEMENT
I would like to express my deep respect to Dr. Edmond Gomes, Professor of the Department of PMRE, for his valuable guidance and supervision throughout the entire work.
I would like to express my profound gratefulness to Dr. A.K.M.A. Quader, Professor of the Department of Chemical Engineering, for his valuable supervision of the work.
I would like to thank Engr. Kh. A. Saleque, GM (R-A Project), GTCL, for his co- operation in providing me with the permission in collecting gas transmission data and
valuable suggestions.
I would like to express my gratitude to Mr. Tahshin Haq, Engineer, UNOCAL Bangladesh Ltd., for providing data and encouragement to complete this work.
I would like to thank A. K. M. Shamshul Alam, GM (Planning and development), JGTDSL, for his administrative support and co-operation, and for providing me with necessary facilities in collecting the required gas transmission and distribution data.
I would like to express my profound gratefulness to my parents for their support and to
my brothers and sisters, for their support and inspiration.
I would also like to thank the University of Alberta-BUET -CIDA linkage Project officials for setting up computer facilities in PMRE department, which made this work possible.
iii USEFUL CORRESPONDENCES
Abbreviations, Acronyms and Terminology
A-B Ashugonj-Bakhrabad
N-S North-South B-D Bakhrabad-Demra B-C Bakhrabad-Chittagong A-E Ashugonj-Elenga MAOP Maximum Allowable Operating Pressure SCADA Supervisory Control and Data Acquisition TFA Titas Franchise Area JFA Jalalabad Franchise Area BFA Bakhrabad Franchise Area WFA Western Franchise Area R-A Rashidpur-Ashugonj Petrobangla Bangladesh Oil Gas and Mineral Corporation (BOGMC) UFFL Urea Fertilizer Factory Limited ZFCL Zia Fertilizer Company Limited APS Ashugonj Power Station CUFL Chittagong Urea Fertilizer Limited BCIC Bangladesh Chemical Industries Corporation EPZ Export Processing Zone IOC International Oil Company NGFF Natural Gas Fertilizer Factory PSC Product Sharing Contract PUFF Pol ash Urea Fertilizer Factory SHELL Shell Bangladesh Exploration and Development B.Y. UNOCAL UNOCAL Bangladesh Ltd.
iv Operating Companies of Petrobangla
BAPEX Bangladesh Petroleum Exploration Company Limited BGFCL Bangladesh Gas Fields Company Limited BGSL Bakhrabad Gas System Limited GTCL Gas Transmission Company Limited JGTDSL Jalalabad Gas Transmission and Distribution Systems Limited RPGCL Rupantarita Prakritik Gas Company Limited SGFL Sylhet Gas Fields Limited TGTDCL Titas Gas Transmission and Distribution Company Limited
Terminology for metering stations
CGS City Gate station, the pressure is being reduced from the transmission pipeline pressure down to 350/300 psig. TBS Town Bordering Station reduces pressure from 350/300 psig down to 150 psig. DRS District Regulating Station reduces pressure from 150 psig down to 50 psig.
Symbols, Measures and Conversion Factors
3 K = 10 Lac = 105 (Bangladesh Terminology) 6 M = 10 (except for MCF) Crore = 107 (Bangladesh Terminology) 9 G = 10 I ton = 1000 kg I barrel (bbl) = 0.159 cubic meter I BTU = 0.252 kilocalorie MCF = thousand standard cubic feet TCF = Trillion (1,000 billion) cubic feet I psig = 0.06895 bar
I atmospheric = 14.7 psia
v
( TABLE OF CONTENTS
. 'Page Chapter No. Abstract HI Acknowledge III Useful Correspondences IV-V Table of Contents VI-IX List of Tables X List of Figures XI-Xll1 List of Appendices XIV
1-3 J. Introduction 4-34 2. Literature Review
2.1 Introduction 4 2.2 Types of Pipelines 5 2.2.1 Gas Pipelines 5 2.2.1.1 Gas Gathering 5 2.2.1.2 Gas Transportation 6 2.2.1.3 Distribution Pipeline 6 2.2.2 Oil Pipelines 6 2.2.3 Product Pipeline 7 2.2.4 Two-phase pipeline 7 2.2.5 LNG Pipelines 7 2.3 Uses of Natural Gas 7 2.4 Sector Wise Natural Gas Consumption 8 2.4.1 Ammonia-Urea Fertilizer Sector 10 2.4.2 Trends of Natural Gas Uses for Power Generation 13 2.4.3 Industrial, Domestic and Commercial Sectors 17
2.5 Gas Sector of Bangladesh 19 2.5.1 Oil and Gas Exploration in Bangladesh 19 2.5.2 Gas Fields of Bangladesh 22
VI 2.5.3 Present Demand and Supply Scenario 27 2.5.4 Future Demand and Supply Scenario 30 2.6 Gas Transmission Network 32
3. PIPESIM 35-41
3.1 Introduction 35 3.2 PIPESIM-Net 35 3.3 Black Oil and Compositional Data 36 3.4 Calibration Data 37 3.5 Model Overview 38 3.6 Network Validation 39 3.7 Flow Correlations 39 3.7.1 Horizontal Flow 39 3.7.2 Vertical Flow 40 3.7.3 Single Phase Correlations 40 3.8 Convergence 41 42-51 4. Gas Transmission System and Related Data
4.1 Introduction 42 4.2 Network Analysis 42 4.3 Gas Composition 46 4.4 Diameter and Length of Transmission Lines 49
5. Steady- State Flow of Gas through Pipes 52-71
5.1 Introduction 52 5.2 Gas Flow Fundamentals 52 5.3 Types of Single-Phase Flow Regimes and Reynolds Number 53 5.4 Pipe Roughness 54 5.5 Pressure Drop Calculations 55 5.5.1 The Pressure Drop due to Potentia! Energy Change 55 5.5.2 The Pressure Drop due to Kinetic Energy Change 55 5.5.3 The Frictional Pressure Drop 56
vii 5.6 Allowable Working Pressures for Pipes 57 r 5.7 Allowable Flow Velocity in Pipes 57 5.8 Horizontal Flow 57 5.8.1 Non- Iteration Equations for Horizontal Gas Flow 58 5.8.2 A More Precise Equation for Horizontal Gas Flow (The 59 Clinedinst Equation) 5.9 Gas Flow through Restrictions 60 5.10 Sub-Critical Flow 60 5.11 Critical Flow 61 5.12 Flowing Temperature in Horizontal Pipelines 61 5.13 Steady-State Flow in Pipeline Networks 62 5.13.1 The Mathematical Models for the Individual NCE's 63 5.13.2 Loop Less System 65 5.13.3 Looped Systems 66 5.13.3.1 Single-Loop System 67 5.13.3.2 Multiple-Loop System 69
6. Simulation Results 72-115
6.1 Introduction 72 6.2 Demand-supply Scenario of High-pressure gas transmission lines 72 of Bangladesh Using Current Data (from 12-July-00 to 13-July-OO)
6.2.1 North-South Gas Transmission Pipe Line 72 6.2.2 Bakhrabad to Chittagong Gas Transmission Pipe Line 74 6.2.3 Ashugonj to Bakhrabad Gas Transmission Pipe Line 75 6.2.4 Bakhrabad to Demra Gas Transmission Pipe Line 75 6.2.5 Ashugonj to Elenga Gas Transmission Pipe Line 75 6.2.6 Titas - Narshingdi - Demra Gas Transmission Pipe Line 76 6.2.7 Titas - Narshingdi - Joydevpur Gas Transmission Pipe 76 Line 6.2.8 Monohordi - Narsingdi - Shiddirgonj Gas Transmission 77 Pipe Line 6.2.9 Western Region Gas Transmission Pipe Line 77
viii 6.2.10 Network Analysis 77 6.3 Modification of Network by Using Known Pressure at Bakhrabad 85 Gas Field 6.4 Modification of Network by Setting up a Compressor Station at 90 Bakhrabad Gas Field 6.5 Gas Demand-Supply Scenario of High Pressure Transmission Line 93 at Maximum Load 6.6 Modified Network Using R-A Loop Line 96 6.7 Extension of Network up to Bheramara 101 6.8 Extension of Network up to Khulna without Modification 104 6.8.1 Extension of Network up to Khulna with A-D Loop Line 107 6.8.2 Modification ofNolka to Khulna line by Using Loop Line 110 from R-A Loop Line to Dhanua 6.8.3 Modified Final Network by Using Compressor Station at 113
Monohordi
116-118 7. Discussions 119-120 8. Conclusions and Recommendations
8.1 Conclusions 119 8.2 Recommendations 120
Appendices 121-143
Nomenclature 144-145
References 146-147
ix LIST OF TABLES
. Page'No'.
Table 2.1 Sector Wise Natural Gas Consumption 9 Table 2.2 Connected Maximum Loads of Gas for Fertilizer Sectors 13 Table 2.3 Trends of Natural Gas Uses for Power Generation 16 Table 2.4 Exploration Phases of Bangladesh 20 21 Table 2.5 Exploration Activities in Bangladesh since 1972 24 Table 2.6 Gas Fields of Bangladesh 25 Table 2.7 Production Capacities of Various Gas Fields Table 2.8 Downstream Demand and Consumption of Natural Gas of Jalalabad 28 Gas Franchise Area (JFA), Greater Sylhet
Table 2.9 Downstream Demand and Consumption of Natural Gas of Titas 28 Gas Franchise Area (TFA) Table 2.10 Downstream Demand and Consumption of Natural Gas of 29 Bakhrabad Franchise Area (BFA)
Table 2.11 Downstream Demand and Consumption of Natural Gas of Western 29 Region Franchise Area (WF A) 31 Table 2.12 Average Base Case SupplylDemand (in MMCFD) Table 2.13 Gas Transmission Network 33 Table 4.1 Gas Composition of Natural Gas in Different Gas Fields 47 48 Table 4.2 Sales Gas Specification ofTitas Franchise Area Table 4.3 Length and Diameter of Major Gas Transmission Pipelines of 49 Jalalabad Franchise Area Table 4.4 Length and Diameter of Major Gas Transmission Pipelines of Titas 50
Franchise Area Table 4.5 Length and Diameter of Major Gas Transmission Pipelines of 50 Bakharabad Franchise Area Table 4.6 Length and Diameter of Major Gas Transmission Pipelines of 51 Western Region Franchise Area Table 6.1 Comparison of Simulated Pressure to the Measured Pressure 83
x LIST OF FIGURES
Page No .. Figure 2.1 Sector Wise Natural Gas Consumption 10 Figure 2.2 Natural Gas Consumption in Bangladesh II Figure 2.3 Urea Plants in of Fertilizer Factories of Bangladesh 12 Figure 2.4 Power Plants in Bangladesh 14 Figure 2.6 Trends of Natural Gas Uses for Power Generation 17 Figure 2.5 Natural Gas Fields in Bangladesh 23 Figure 3.1 Types of Network Used in PIPESIM-Net 38 Figure 4.1 The Geographical Areas for the Gas System Development Plan 43 Figure 4.2 Gas Transmission Network, Main High Pressure Lines III 45 Bangladesh Figure 4.3 Gas Transmission Network, Possible Extension m the Western 46 Region Figure 5.1 Loop Less Pipeline System 65 Figure 5.2 Single Looped Systems 67 Figure 5.3 Multiple Looped System 67 Figure 5.4 Illustration for Stoner's Method 69 Figure 6.1 High Pressure Gas Transmission Lines of Bangladesh Using 73 Current Data Figure 6.2 Variation of Pressure along the Major Gas Transmission Lines 78 78 Figure 6.3 Change of Flowrate along the Major Gas Transmission Lines Figure 6.4 Change of Liquid Hold up along the North-South line 80 Figure 6.5 Demand-Supply Scenario of High-pressure Gas Transmission 81 Lines of Bangladesh Modified by Known Pressure at Ashugonj
Figure 6.6 Calculated and Measured Pressure along the N-S Line 82 Figure 6.7 Variation of Pressure along the Major Gas Transmission Lines 82 after Modification Figure 6.8 Variation of Pressure along the Major Gas Transmission Lines 84 Figure 6.9 Demand-Supply Scenario of High-pressure Gas Transmission 87 Lines Modified by Using Known Pressure at Bakhrabad Gas Field
xi 88 Figure 6.10 Variation of Pressure along Major Transmission Lines Modified by Using Known Pressure at Bakhrabad Gas Field 88 Figure 6.11 Variation of Flow Rate along Major Transmission Lines Modified by Using Known Pressure at Bakhrabad Gas Field 89 Figure 6.12 Effect of Separator on North-South Line 91 Figure 6.13 Demand-Supply Scenario of High Pressure Gas Transmission Lines Modified by Setting up a Compressor Station at Bakhrabad
Gas Field 92 Figure 6.14 Variation of Pressure along Major Gas Transmission Lines by Dropping Bakhrabad Gas Field from the Network 92 Figure 6.15 Change of Flow Rate along Major Gas Transmission Lines by Dropping Bakhrabad Gas Field from the Network. 93 Figure 6.16 Effect of Compressor at Bakhrabad Gas Field 94 Figure 6.17 Gas Demand-Supply Scenario of High Pressure Transmission Line at Maximum Load 95 Figure 6.18 The Variations of Pressure along the Major Transmission Lines Modified by Maximum Load 95 Figure 6.19 Change of Flow Rate along the Major Transmission Lines Modified by Maximum Load 98 Figure 6.20 Demand-Supply Scenario of High Pressure Gas Transmission Lines Modified Network by Using R-A Loop Line 99 Figure 6.21 The Variations of Pressure with the Length after Modified by R-A Loop Line 99 Figure 6.22 Change of Flow Rate with the Length after Modified by R-A Loop Line 100 Figure 6.23 Demand-Supply Scenario of Gas Transmission Lines Modified by Using R-A Loop Line and Mentioning Known Pressure at
Ashugonj 101 Figure 6.24 The Variations of Pressure with the Length after Modified by R-A Loop Line for Pressure Matching
xii Figure 6.25 Demand-Supply Scenario of High Pressure Gas Transmission 102 Lines by Extension of Network up to Bheramara Figure 6.26 Variation of Pressure Drop along Major Transmission Lines by 103 Extension of Network up to Bheramara Figure 6.27 Change of Flow Rate along the Major Transmission Lines by 103 Extension of Network up to Bheramara Figure 6.28 Demand-Supply Scenario of High-pressure Gas Transmission 105 Lines by Extension of Network up to Khulna without Modification Figure 6.29 The Variation Pressure of Major Transmission Lines by Extension 106 of Network without any Modification Figure 6.30 Change of Flow Rate along the Major Transmission Lines by 106 Extension of Network without any Modification Figure 6.31 Demand-Supply Scenario of High Pressure Gas Transmission 108 Lines by Extension of Network up to Khulna with A-D Loop Line Figure 6.32 The Variation of Pressure along the Major Transmission Lines by 109 Extension of Network up to Khulna with A-D Loop Line. Figure 6.33 Change of Flow Rate along the Major Transmission Lines by 109 Extension of Network up to Khulna with A-D Line Figure 6.34 Demand-Supply Scenario of High Pressure Gas Transmission III Lines modified by Using Loop Line from R-A Loop Line to
Dhanua Figure 6.35. The Pressure Drops of Major Transmission Lines of Nolka to 112 Khulna Pipeline Using Loop Line from R-A Loop Line to Dhanua Figure 6.36 Change of Flow Rate along the Major Transmission Lines of 112 Nolka to Khulna Pipeline Using Loop Line from R-A Loop Line
to Dhanua Figure 6.37 Demand-Supply Scenario of High Pressure Gas Transmission 114 Lines modified Final Network by Using Compressor Station at
Monohordi Figure 6.38 The Variation of Pressure along the Major Transmission Lines lIS modified by Using Compressor Station at Monohordi
Xlll LIST OF APPENDICES
-1IP .. :" -~---_.,_ .. _~-<>---. ----. -~--~--~--- ,"
121 Appendix I Simulated Results of High Pressure Gas Transmission Lines of Bangladesh 123 Appendix 2 Simulated Results of High Pressure Gas Transmission Lines of Bangladesh modified by Known Pressure at Ashugonj 125 Appendix 3 Simulated Results of High Pressure Transmission Lines Using Known Pressure at Bakhrabad Gas Field. 127 Appendix 4 Simulated Results of High Pressure Transmission Lines by Setting up a Compressor Station at Bakhrabad Gas Field 129 Appendix 5 Simulated Results of High Pressure Transmission Lines at Maximum Load. 130 Appendix 6 Simulated Results of High Pressure Transmission Lines Modified Network Using R-A Loop Line. Pressure Transmission Lines 132 Appendix 7 Simulated Results of High Modified Network Using R-A Loop Line by Using Known
Pressure at Ashugonj. High Pressure Transmission Lines 135 Appendix 8 Simulated Results of Modified Network by Extension of Network up to Bheramara. Pressure Transmission Lines 137 Appendix 9 Simulated Results of High Extension of Network up to Khulna without any Modification Pressure Transmission Lines 138 Appendix 10 Simulated Results of High Extension of Network up to Khulna with A-D Loop Line. Lines, 140 Appendix II Simulated Results of High Pressure Transmission Modification of Nolka to Khulna Line by Using Loop Line
from R-A Loop Line to Dhanua Pressure Transmission Lines 143 Appendix 12 Simulated Results of High ~ Modified Network by Using Compressor Station at Monohordi
xiv Chapter 1
INTRODUCTION
The importance of mineral and energy resources cannot be over emphasized in a developing country like Bangladesh. These resources are not only considered as the driving " force but also the backbone of modem economy. These are vital requirement for industrialization, power generation etc. and thus for enhancement of the social standards of people through economic development and attainment of comfortable life style. In this context it is important that the government should make sincere efforts for the development
of this sector.
Natural gas is the most important non-renewable resources in Bangladesh. Over the years it has acquired a position as.an alternative to oil. It is also regarded, as a main source of power generation. Its use and requirement has been greatly enhanced in recent times. During the pre-liberation period, around 1968-69, the use of gas stood at 19 percent of total commercial energy only, when the consumption of oil was more than 70 percent. From 80's the consumption of natural gas rose a little above 37 percent, and by 90's the consumption :':"- of gas exceeded 70 percent and simultaneously it distinct decrease was noticed in the consumption of oil and it came down to 30 percent.
Bangladesh has discovered 22 gas fields and one oil well (Sylhet 7 at Haripur). But 12 producing gas fields can produce 1300 MMCFD of gas from 53 gas wells. In 22 gas fields,
total GIIP (proven + probable) reserve is about 24.745 TCF of which about 15.507 TCF (1)
has been confirmed. Out of recoverable reserve, 4.08 TCF gas has been consumed (I). The
present peak demand of 1089 MMCFD (2) which can now be met from the current peak production of 1300 MMCFD after drawing gas from private producers, namely, UNOCAL il., Bangladesh Ltd. and Shell Bangladesh Exploration and development B.V. Of the total gas produced, 35 percent is used for fertilizer, 45 percent for power generation and 20 percent
for other purpose (I). The gas transmission pipelines In Bangladesh were initially planned and constructed targeting particular bulk consumers or potential load centers. In the early stage of the development of the gas sector, the grid system was not visualized. But over the years the gas transmission system has expanded considerably and has become complicated. Four Companies of Petrobangla'such as Gas Transmission Company Ltd. (GTCL), Titas Gas Transmission and Distribution Company Ltd. (TGTDCL), Bakhrabad Gas Systems Ltd. (BGSL), Ialalabad Gas Transmission and Distribution Company Ltd. (IGTDCL) and two international companies (Unocal Bangladesh Ltd., Shell' Bangladesh Exploration and Development B.V.) are responsible for operation and maintenance of their respective
transmission pipelines.
As new gas based industries and power plants are being set up, the existing gas transmission system is being stressed to meet the demand. To overcome this, a loop line is being constructed from Kailashtilla to Ashuganj to flow more gas from Sylhet region. To study the performance and the effect of any future development, it is required to analyze the
whole transmission network.
The objective of this study is to perform gas transmission network analysis of Bangladesh.
Various components of the objective are: i) to simulate the present gas transmission net~ork system and compare with the
actual performance ii) to identify any limitation of the system iii) to study the effect of future pipeline expansion, loads etc.
This study has been carried out using a software called PIPESIM. Baker Iardine Inc. (UK) developed it. Building the pipeline network using the software can be divided in to a
number of stages: 1. Collecting all necessary data on the transmission network J; 2. Setting up the model and naming components 3. Setting global default (fluid composition, unit etc.) 4. Setting boundary conditions at wells, sources and sinks (loads)
2 5. Running the model and analyzing the results
The study has been undertaken to simulate the present network system, identify its limitations and suggest remedial measures. This study would be useful to understand the performance of the present gas transmission system of Bangladesh. This study would also analyze the existing pipeline capacity and examines the level of capacity utilization. The simulated results will be helpful to identify the bottlenecks and to plan for future expansion .~ of gas transmission system.
( '-
3 " Chapter 2
LITERATURE REVIEW
2.1 Introduction
The natural gas has established itself as a major indigenous hydrocarbon resource in Bangladesh. It is the chief source of fuel for industrial, commercial and household operations as well as for power generation. On September 18, 2001 the production was
1042 MMSCFD and the two laCs' contribution was 176 MMSCFD (1) The present peak demand is about 1089 MMSCFD.
The first discovery of natural gas was made in 1955 at Haripur. Since then the exploration has led to the discovery of 22 gas fields and one oil field. There are now 53 producing wells capable of producing about 1300 MMSCFD of gas from 12 gas fields (1) The exploration activities for gas and oil in Bangladesh started with the exploration at Sitakunda in 1908.
National Energy Policy (NEP), promulgated in 1995, indicated an energy-growth rate of 8.77% by year 2000 equivalent to 12 million tons of oil and 19 million tons of oil equivalents, representing energy growth rate of 8.86% (3). The major part of the future energy demand would be met from natural gas and it is estimated that gas demand would reach about 1450 MMSCD (average) and 1700 MMSCFD (maximum) by 2005 and 1900
MMSCFD (avg.) and 2250 MMSCFD (4) by 2010 (max.) ..
The uses of Natural gas in Bangladesh can be broadly classified into five categories, namely, power, fertilizer, industrial, commercial and domestic. The fertilizer sector utilizes natural gas as a feed stock as well as fuel while the remaining sectors use it as a fuel. The current consumption pattern shows that fertilizer sector consumes approximately 35%, power 45% and other sectors (industry, domestic, commercial arid seasonal) 20% of the gaseS). \, !
4 2.2 Types of Pipelines
A network of sophisticated pipeline systems transports oil, natural gas and petroleum products from producing fields and refineries around the world to consumers in every nation. This network gathers oil and gas from hundreds of thousands of individual wells, including those in some of the world's most remote and hostile areas. It distributes a range of products to individuals, residences, businesses and plants.
Most gas and oil pipelines fall into one of three groups: gathering, transportation or
distribution (6) Other pipelines are needed in producing fields to inject gas, water or other fluids into the formation to improve gas and oil recovery and to dispose of salt water often
produced with oil.
2.2.1 Gas Pipelines
In general, gas pipelines operate at higher pressure than crude lines; gas is moved through a gas pipelines by compressor rather than by pumps; and the path of natural gas to the user is
more direct.
2.2.I.I Gas Gathering
Gas well flow lines connect individual gas wells to field gas treating and processmg facilities or to branches of a large gathering system. Most gas wells flow naturally with sufficient pressure to supply the energy needed to force the gas through the gathering lines to the processing plant. Down hole pumps are not used in gas wells, but in some very low pressure gas wells, small compressors may be located near the well head to boost the pressure in the line to a level sufficient to move the gas to the process plant.
5 r'I \ '_ ..\ 2.2.1.2 Gas Transportation
From field processing facilities, dry, clean natural gas enters the gas transmission line system for movement to cities where it is distributed to individual business, factories and residences. Distribution to the final users is handled by utilities that take custody of the gas from the gas transmission. pipeline and distribute it through small, metered pipelines to individual customers.
Gas transmission lines at relatively high pressures. Compressors at the beginning of the line provide the energy to move the gas through the pipeline. Then compressor stations are required at a number of points along the line to maintain the required pressure. The distance between the compressors varies, depending on the volume of gas, the line size and other factors. Adding compressors at one or more of these compressor stations or by building an additional compressor station often increases capacity of the system. The size of the compressors with in the station varies over a wide range, but many stations include several
thousand horsepower in one station.
2.2.1.3 Distribution Pipeline
Through distribution networks of small pipelines and metering facilities, utilities distrjbute natural gas to commercial, residential and industrial users.
2.2.2 Oil Pipelines
Flow lines, the first link in the transportation chain from producing well to consumer, are used to move produced-oil from individual wells to a central point in the field for treating
and storage.
6
• 2.2.3 Product Pipeline
The industry's products pipeline system is a sophisticated network. Many segments of the system are highly flexible in both capacity and the products that can be transported. One part of this system moves refined petroleum products from refineries to storage and distribution terminals in consuming areas. Another group of product pipelines is used to transport liquefied petroleum gases (LPG) and natural gas liquid (NGL) from oil and gas processing plants to refineries and petrochemical plants.
2.2.4 Two-phase Pipeline
In most cases, it is desirable to transport petroleum as either a gas or a liquid in a pipeline. In a line design to carry a liquid, the presence of gas can reduce flow and pumping efficiency; in a gas pipeline, the presence of liquids can reduced flow efficiency and damage gas compressors and other equipment.
2.2.5 LNG Pipelines
Liquefied natural gas (LNG) is natural gas cooled and compressed to a temperature and pressure at which it exits as a liquid. Significant volumes of natural gas are transported in the liquid phase as LNG, but these shipments are made by special ocean tanker rather than
by long distance pipeline.
2.3 Uses of Natural Gas
The uses of natural gas in Bangladesh can be broadly classified into the following five
categories: Fertilizer: As raw material for production of Urea Fertilizer. Power: As fuel for generation of electricity. Industrial: As fuel for various industries.
Commercial and ( I 7 \ oj Domestic. ) The current consumption pattern shows that fertilizer (ammonia-urea) sector consumes approximately 35%, power 45% and other sectors (industry, domestic, commercial and
seasonal) 20% of the gas (5).
2.4 Sector Wise Natural Gas Consumption
During the international energy crisis of the 1970's, the rapid rise in international oil prices increased the demand for natural gas in different sectors for its lower cost. A more attractive incentive to use natural gas is its easy and clean burning with environment benefits. With the growth of the economy, demand for energy has increased.
From Table 2.1 and Figure 2.1 show that natural gas consumption In the power and fertilizer sector started increasing drastically in the mid-80s. This is because at that time most of the power plants in the eastern grid was being converted from diesel to natural gas and at the same time some new power plants based on gas were added to the national grid. In the fertilizer sector, three big urea plants were installed from the middle of 80s to the beginning of 90s. Industrial and commercial demands also increased during that period, although the overall percentages or these two sectors were not as significant as the other
two.
In 1996-97, consumption of natural gas in fertilizer sector decreased due to supply crisis of natural gas in the Chittagong region. As a result, Chittagong Urea Fertilizer factory (CUFL) stopped its production. Power sector was given priority for supplying gas at that time. After completion of Ashuganj-Bakhrabad pipeline (A-B pipeline) and production of gas from Sangu and Jalalabad gas field by two IOCs, CUFL again started production and natural gas consumption in fertilizer sector increased. A similar supply shortage also occurred during 1989-91 'period due to a fatal accident at Ghorasal Fertilizer Factory. Presently there is no ". shortage of supply and daily demand is about 930 MMSCFD.
8 Table 2.1 : Sector Wise Natural Gas Consumption (8)
~'_". ~~~I.~-r "':~~-":=!'I')";',-~~..:~~' .•.~~"' '.- - ,~ .,. I- .,"'" Year - ., ~:; - "'Sectors (MMSCF):-', Power Fertilizer Industrial Commercial. Domestics • Total 1967-68 225 0 0 0 0 225 1968-69 1019 0 5 9 I 1034 1969-70 1140 1828 145 26 4 3143 1970-71 3419 4225 255 41 22 7962 1971-72 3103 602 322 33 36 4096 1972-73 4513 9669 843 66 87 15178 1973-74 7419 10559 1462 115 146 19701 1974-75 6063 2098 1784 181 277 10403 1975-76 6535 11018 2334 266 489 20642 1976-77 8200 10027 3047 370 766 22410 1977-78 9327 8311 3742.17 571.27 1125.43 23076.87 1978-79 9209 11146 4557.36 854.55 1873.09 27640 1979-80 11018 11975 5182.99 1078.10 2561.84 31815.93 1980-81 13321 11210 5978.60 1342.47 3390.00 35242.07 1981-82 18010 19836 7391.06 1680.98 4214.25 51132.29 1982-83 21999 19140 7812.44 1917.57 5217.24 56086.25 1983-84 22886 25805 8687.83 2057.67 5785.14 65221.64 1984-85 38292.70 24296 11447.76 2232.62 6318.95 82588.03 1985-86 39778.27 30070.50 16352.56 2721.54 6796.95 95719.82 1986-87 51852.09 33474.5 18673.16 3415.81 6840.79 114256.35 > 1987-88 63054.45 50978.72 15665.47 3603.63 7590.41 140892.68 1988-89 66455.80 57886.51 1497.08 3126.15 9261.28 151026.82 1989-90 75557.45 55909.11 13892.44 3098.67 10418.70 158876.37 1990-91 82556.11 54172.33 13911.78 2930.55 10529.37 164100.14 1991-92 88105.07 61642.31 14088.55 3135.73 11645.93 178617.59 1992-93 93212.08 69176.18 15801.05 2547.99 13495.68 194232.98 1993-94 97491.11 74434.89 19895.15 2853.89 15603.05 210278.09 1994-95 107437.37 80464.44 23891.25 2896.42 18781.78 233471.26 1995-96 110827.15 90979.45 27189.53 3029.01 20776.44 252801.58 1996-97 110864.20 77828.57 29303_97 3393.48 22869.06 244259.28 1997-98 123391.93 80000.68 33046.61 3496.83 24984.67 264920.72 1998-99 140837 82730 35779 3652 27183 290181 1999-00 149355 84894 41271 3836 29675 309031 2000-01 175204 88465 48094 4066 31872 347701 , Total 1761678 1254852 433349.8 64645.93 300638.1 3827964 '.- .'..\!!~..( 9 .• .•.... ~ •• • In 1968-69, out of a total consumption of 1034 MMSCF, power sectors alone used 98% of the total gas and commercial, industrial and domestic sectors together used only 2%. With the introduction of gas in the Urea Fertilizer Factory Limited (UFFL) at Ghorasal in 1970, the total demand for gas stood at 7962 MMSCF. Percentage use of gas in power, fertilizer, industrial and commercial sectors was43%, 53%,4% and 0.5% respectively. Domestic use of gas was 3% in 1970-71, which increased to 8% in 1979-80. Use of gas in power sector kept on increasing and in 1996-97 its share was 46%. Figure 2.1 shows percentage of gas consumption in different sectors from the beginning of its use. It is anticipated that more and more gas would be used to meet the power demand of the country.
_.~~------400000 -+- Power ~ 350000-11- Fertilizer u 2 300000 Industrial ::8 250000 Commercial . --lIE- Domestic .~ 200000 a- 150000 __ Total ;:l :g 100000- o u 50000.'
o -- w -~-~----~~-~~~~~~~-T-'~'--'-T-'-'-'-'-r-' I
. _.__ __.~96: __._1_97_0 1_975 1~8_0__Year_1985 .~_90__ 1~~___ 2~~~_ J
Figure 2.1: Sector Wise Natural Gas Consumption (8)
2.4.1 Ammonia-Urea Fertilizer Sector
Seven ammonia-urea complexes now in operation have a combined connected demand of
289 MMSCFD of gas (5). Table 2.2 shows the growth of this sector, and Figure 2.2 shows the consumption trend of gas since 1960 with the commissioning of each plant. During the decade of 1988-1997 the share of this sector accounted for 32 to 37 % of the total gas
consumed (5). The locations of fertilizer factories are shown in Figure 2.3. (
10 . 2008 .2007 2006 2005 2004 2003 2002 2001 2000 1999 1998 . 1997 1996 ~ ~ 1995 0 1994 -u 1993 VJ 1992 "~ ~~ " . "'!" ::; ••• 1 1991 '. N u ' .~" N u.. : 1990 .;:: , is ~ ~ 1989 1988 u-" LL-' ri r:: ::> 1987 .S u 1986 . (:l::JSIJIJiI\I)UO!ldlUnsuo::J se~ , , ,, . "~" _ L I 'I, v "r1 A ~. TRIPURA ~ ", "N ". w ,.,;,'" (INDIA) See delailed map C~ " r'\. r, '""C r , J" ( N ~ \ - ~ •••••••••• , 5"'" "',-,') \ \ Comi'Aa J \ to I , ;- gj / '" \ 03- I \ ", ( \ '"p.. \,r~," \ '\ , I(, '"::r'" I l,Jessore \ I- ,\ , \ :s \,., \ \ , Ii Felli lown '" 23' ~ ---;;;:;;'/Relll~-----7 ill ~'\ Semula~ / , *"/Manldrlle'il , ~ {;.1k:hhIri .., \. I I \ I ~ '.HlIltIIlarl I 1 o , . \ II J:.[/"f-h! ) I ~- . I'" /, Table 2.2: Connected Maximum Loads of Gas for Fertilizer Sectors (5) From Year Plant " ' Load(MMSCFD) ,.' Cumull:1tiv~(MMSCFD) 1961 NGFF 19 19 1970 UFFL 45 64 1981 ZFCL 50 114 1986 PUFF 17 131 1987 CUFL 50 181 1991 JFCL 43 224 1994 KAFCO 65 289 During the period 1986 to 1987, a gas load of 67 MMSCFD was added by the fertilizer sector with the commissioning of PUFF and CUFL while an additional load of 108 MMSCFD was added during 1991-94 when JFCL and KAFCO came on stream. The average daily demand of gas by the fertilizer sector for the years 1986, 1989 and 1996 were 103, 154 and 213 MMSCFD respectively against the contracted loads of 121,171 and 284 MMSCFD respectively. During the next five years, the most optimistic annual consumption of gas would be 90,000 MMSCFD by this sector. 2.4,2 Trends of Natural Gas Uses for Power Generation From the present trend of economic growth in different areas it is clear that most of the future gas demand would come from the power sector. A more detailed and lists of the gas demand scenario in power sector enable us to have a better understanding of the growth projection. The location of gas based power stations of Bangladesh are shown in Figure 2.4. Natural gas was first introduced on a trial basis for power generation in Bangladesh in 1967 in a 30 MW power plant at Siddirgonj. Use of gas to produce electricity increased steadily and in 1999 installed generating capacity by using natural gas stood at 2575 MW which is about 75% of the total installed capacity. In December 1999, natural gas was supplied to the western zone for the first time and it is expected that several gas-fired power plants would be established in the power starved western zone of the country. 13 I- v >r1 .A. QQ' TRIPURA ..., 2~.~" '" / tv (I N D I A I '" /.;/ ~ Kushlla See de1ailed map -0 0 rJ ~ r r \.r\ ..., \. J ~ '" \" I I -0 I , -..,. ::l '-I \ I fA .- '" Com" J , .r :; \ ./ \ OJ I \ ~ "\ { I <;) ------Table 2.3 shows that natural gas consumption started increasing in power generation from the very beginning after the installation of a 30 MW trial plant in 1967. Conversion of the old oil-fired plants and addition of some new power plants pushed the total demand of gas to the present value. From Figure 2.5 it is clear that in mid 80's, natural gas used power generation increased sharply. This was due to the addition of three 210 MW units at Ghorasal and three 150 MW units at Ashuganj. In mid 90's another new power plant at Raozan with two units each of 210 MW capacity was added to the national grid. A sharp rise in natural gas consumption curve can be observed during that period. Furnace oil and HSD/SKO consumed in power generation, mainly in the remote areas and western zone where natural gas is not available remains almost same from the beginning. Natural gas completely replaced the use of naphtha and coal in power generation in 1972 and 1983 respectively. 15 Table 2.3: Trends of Natural Gas uses for Power Generation (10). Installed Capacity by Type ofFuel(MW) . Total " Year installed Hydro Coal Furnace Natural Naphtha HSD/SKO Capacity Oil Gas 1966-67 80.00 30.96 30.00 30 79.20 220.16 1967-68 80.00 30.96 117 124.59 265.55 1968-69 80.00 6.00 24.96 181.50 37.00 95.34 360.30 1969-70 80.00 4.16 20.80 316.40 43.50 89.00 418.96 1970-71 80.00 4.16 20.80 316.40 45.70 81.64 548.70 1971-72 80.00 4.16 20.80 316.40 45.70 81.64 548.70 1972-73 80.00 4.16 80.80 371.40 45.70 81.23 608.29 1973-74 80.00 stoDDed 84.96 371.40 45.70 78.03 660.09 1974-75 80.00 84.96 426.40 45.70 85.38 667.44 1975-76 80.00 84.96 426.40 45.70 128.52 765.58 1976-77 80.00 84.96 426.40 45.70 129.60 766.66 1977-78 80.00 84.96 426.40 32.70 128.08 752.14 1978-79 80.00 76.64 426.40 7.20 127.74 717.98 1979-80 80.00 80.00 426.40 234.79 822.19 1980-81 80.00 80.00 426.40 226.76 813.16 1981-82 130.00 80.00 414.00 233.00 857.00 1982-83 130.00 76.64 474.00 6.50 232.10 919.24 1983-84 130.00 182.45 564.00 13.00 231.55 1121.00 1984-85 130.00 182.45 577.00 StoDDed 251.55 1141.00 1985-86 130.00 170.00 633.00 238.23 1171.23 1986-87 130.00 170.00 1069.00 238.33 1607.23 1987-88 230.00 170.00 1468.00 278.23 2146.23 1988-89 230.00 170.00 1678.00 278.28 2365.28 1989-90 230.00 170.00 1678.00 274.21 2352.21 1990-91 230.00 170.00 1678.00 271.93 2349.93 1991-92 230.00 170.00 1875.00 332.68 2397.68 1992-93 230.00 170.00 1875.00 332.68 2607.68 1993-94 230.00 170.00 2175.00 332.68 2607.68 1994-95 230.00 170.00 2175.00 332.68 2907.68 1995-96 230.00 170.00 2175.00 332.68 2907.68 1996-97 230.00 170.00 2365.00 326.00 2907.68 1997-98 230.00 170.00 2365.00 436.00 3091.00 1998-99 230.00 170.00 2575.00 436.00 3411.00 16 'c 'Q) '+-.2 4000 -~-----_.- --:.. - o __ Hydro-all ~ 3500 - __ Coal ~ 3000 Furnace oil £; 2500 Natural gas >-~ .0 S 2000 __ Naphtha >-:2 '5 ~1500 - -- HSD/SKO ro g- 1000'-::+- ~?ta~ _ 1-- u "0 500 Q) 1\ ' -- -'~.•.•.~' ,ro -,--.---.:1:: I~ 0 I ~ 1960 1970 1980 1990 2000 Year ---_.-----_._------_.------_._._------_.----~----_. __ .- Figure 2.5: Trends of Natural Gas uses for Power Generation (10) 2.4.3 Industrial, Domestic and Commercial Sectors In the current decade, percentage of total gas consumed by the combined industry, domestic and commercial sector uses between 16 and 22. Commercial consumers account for less than 1.5% of the total gas consumption and the sector has not shown significant growth during the past decade. Industry, the main contributor among others has reached again the 1986-87 level after years of substantial decline. This fall is partly related- to the poor growth performance of the manufacturing sector in Bangladesh, only 3.1% as yearly growth for the period 1980-92. During the same period the whole industry had better performances since the growth rate has reached 5.1% a year for the period 1990-92 according to World Bank statistics. The industrial sector during the current decade has been using 8 to 12% of the total gas consumption. Major application areas in this sector include steam generation, captive power 17 r;:. 1 '. and for process (heating media and heat source). When the Bakhrabad Gas Systems Ltd. had made natural gas available in Chittagong area, industries using furnace oil, disel or other liquid fuels immediately switched over to gas. These include ERL, TSP, KPM, KRC, Osmania Glass, Chittagong Steel Mills, etc. For the industry sector, the growth has been 3.75% during the decade 1986-1995. In Bangladesh, the domestic sector has ex'perienced a steady growth since the beginning. Within the Titas Franchise area the average growth has reached 9.7% a year from 1980-81 to 1993-94. For Bakhrabad Franchise area development of gas sales to domestic consumers' remains extremely strong since during the 90's, growth is constantly above 12%. In the lalalabad Franchise area the growth is more modest with 4.8%. Comparatively to other developing countries, this is a salient success of the Bangladesh gas sector to have provided an access to low cost energy to hundreds thousands of residential consumers living in cities. Its contribution to maintain trees and forests in the heavily populated Bangladesh deserves to be underlined. The number of domestic consumers now stands approximately at 900,000. The three transmission and distribution companies can provide gas supply to about 70,000 new customers each year (Titas: 50,000, Bakhrabad: 15;000 and lalalabad: 5,000). The domestic sector has shown a growth of 11.7% during the decade 1986-1995. The seasonal uses, mainly the brick fields, consume a small quantity of gas during the brick manufacturing season. This is a minor sector for near future. According to TGTDCL, during the year 1996-97, a domestic consumer consumed about 82 SCFD while an industrial and a commercial consumer consumed 31,000 SCFD and 1031 SCFD respectively. System loss was close to 9 percent. Since 1998, the system loss amounting to 55 MMSCFD has been added to the industrial sector(\). 18 2.5 Gas Sector of Bangladesh Being reverie delta having porous and permeable hydrocarbon bearing sand structure and unique condition of trap Bangladesh is always considered a gas prone country. But due to resource constraint the exploration activities were kept to a bare minimum. Exploration of hydrocarbon in this region commenced from the beginning of the current century. Various national and international companies carried out wild cat exploration in the potential areas of Bangladesh. 2.5.1 Oil and Gas Exploration in Bangladesh Oil/gas reserves are non-renewable energy resources depleting with time. Therefore, every country will have to continue the search to add new reserve to its existing one. Investment in the oil/ gas exploration is a high-risk gamble. It has also different steps leading to successful economic production. The steps are Geological and Geophysical Survey, Data Acquisition, Analysis and Interpretation leading to delineation of a structure, Selection of drilling location etc. The exploration for hydrocarbon was initiated for finding oil in 1908 with the first exploratory well drilled at Sitalakundu. This was followed by three more exploratory wells by 1914. In the early days (1910-1933) of exploration, drilling was mainly concentrated near seeps in the fold belt. At this stage shallow wells ranging from 763 to about 1050 meters were drilled. The foreign companies drilled six exploration wells but no success was met. Second World War disrupted the drilling activities. The second phase of drilling (1915-1917) unfolded a glorious chapter in the exploration history of this part of the world. The exploration activities since 1908 can be broadly divided into five distinct phases as listed in Table 2.4. 19 ( t" Table 2.4: Exploration Phases of Bangladesh (\, 2) . , , , Period " No, of Discovery • 'SticcessRatio Phase • • , 1 . ' . Exploratory " Wells - -- Zero I 1010-1933 6 None British India Minor Oil flow 2,75:1 II 1951-71 22 8 Gas Fields Pakistan 4.50:1 III 1972-78 10 2 Gas Fields (One offshore)' 2,00:1 IV 1979-1992 14 7 Gas Fields & I Oil Field V 1993-2000 10 5 Gas Fields 2.60:1 Total 62 22 Gas Fields & 1 Oil 2,87:1 field In a country where possibility of transfonning resources to reserve is high, there comes PSC mechanism to boost up the cxploration activities through International Oil Company's investment. That was the time where International Oil Companies started becoming contractors and partners to the State Oil Company, The country has been divided into 23 blocks for PSc. Six laCs were awarded 7 blocks under PSC for exploration of hydrocarbon in the early seventies, During the period 1974-77, seven exploratory wells were drilled with only one gas field discovery. A new model PSC was prepared in 1988, 4 blocks were awarded to two laCs who drilled 4 exploratory wells leading to the discovery of one gas field. In the early nincties, the model PSC of 1988 was revised and 8 blocks have been awarded to four laCs. Two of these laCs have so far drilled 14 exploratory wells since 1994 resulting in the discovery of 3 gas fields including one offshore field; and have suffered one gas well blowout. With the discovery of a gas structure in the Bay of Bengal by Anglo Dutch joint venture company Cairn-Shell in 1996, Bangladesh attained the world focus and was being thought to become a happy play ground of the oil majors. There was tremendous response in the second bidding round for selecting International Oil Companies (laC) for exploration in the fifteen blocks. During the period 1972-2000, Petrobangla drilled 16 exploratory wells and discovered 9 gas fields and one oil field. Table 2.5 lists the exploration activities since 1972. 20 o Table 2.5: Exploration Activities in Bangladesh since 1972(1,5) Period No, of Exploratory . Discovery Remarks Wells Drilled Petrobangla 1972-1990 13 7 Gas Fields and I Oil Field 1991-2000 3 2 Gas Fields International Oil Company (lOC) 1974-1978 7 I Gas Field PSCs Cancelled 1988-1995 4 I Gas Field PSCs Cancelled 1994-2000 14 3 Gas Fields In terms of gas reserves, IOCs under a wide range of PSCs have made major gas discoveries in Bangladesh, These IOCs including those operating during pre-I 972 era have discovered total recoverable reserves of 14.19 TCF from twelve fields while Petrobangla ,J has discovered a total recoverable gas reserve of 1.47 TCF from ten fields. Since the emergence of Bangladesh, the IOCs' exploration has contributed 4.46 TCF to recoverable gas reserves and Petrobangla's discoveries have contributed 1.24 TCF to recoverable gas \. reserves (I) During the past decade beginning from 1991, the exploratory drilling program has not gained the desired momentum in spite of the presence of IOCs. Only 13 exploratory wells were drilled which means about 1.3 wells per year. Since 1997 BAPEX, the Exploration Company of Petrobangla, has not undertaken any exploratory drilling. At this moment IOCs have slowed down their exploratory drilling programs in view of the fact that they are. unable to market the gas at the rate that they can produce. If IOCs are allowed to produce from all their fields at the maximum production rate as per PSC, Petrobangla will have to suspend its production from its own fields. The economic reality of Bangladesh is that Petrobangla should buy the minimum quantity of gas from IOCs to meet the country's gas demand and it should not suspend production from any of its producing fields to make room for IOCs production. This is a painful situation for both Petrobangla and IOCs. If we want to take advantage of the technological capability and financial strength of IOCs for accelerating exploratory drillings to augment the existing gas reserve of Bangladesh, one 21 • C::o c must examine all the options available for the marketing and utilization of thew gas from the fields discovered and owned by IOCs. On the other hand GOB has also signed International Power Purchase (IPP) contracts with international power producing companies for setting up gas based power plants on Build Owned and Operate (BOO) basis in Haripur, Meghnaghat, Baghabari and Sirajgonj. Some peaking power plants may also be setup around Dhaka City to meet the peak demand of Dhaka Metropolis and adjoining areas. The expansion of Gas Transmission Network on the Western of the Jamuna river using the Multipurpose Bridge has also opened avenues for setting up gas based industries in the earlier neglected Western region. For ensuring gas supply in time to all the future power plants and industries, expansion and balancing of the national grid require to be implemented on priority basis. Otherwise gas transmission network may have to encounter the same embarrassing situation in the next couple years as being experienced in the power sector. The constraints of the gas transmission grid require to be overcome through construction of loop lines and setting up of compressor stations at strategic locations to expand the capacity of the national gas grid for balancing the system and ensuring security of supply (2). 2.5.2 Gas Fields of Bangladesh The first discovery of natural gas was made in 1955 at Haripur (Sylhet Gas Field) and this was followed by the discovery of the Chhatak Gas Field in 1959. Since then the exploration of oil and gas resources has led to the discovery of 22 gas fields and one oil field. There are now 53 producing wells capable of producing about 1300 MMSCFD of gas from 12 gas fields (I). The locations of gas fields of Bangladesh are shown in Figure2.6. Cumulative production of gas up to December 2000 was about 4.08 TCF (I). Gas fields of Bangladesh have Gas initially in Place (GIIP) of about 24.745 TCF. Summaries of gas initially in place (GIIP) and reserve estimates of different gas fields by Petrobangla are shown in Table 2.6. 22 GAS TRANSMISSION PIPELINES, GAS FIELDS & OIL FIELD OF BANGLADESH WEST BENGAL 8akhrabad Franchise Area Titas franchise Area Jalalabad Franchise Area Wes Gas Franchise Area Cas Transmission Pipelines Proposed Transmission Pipelines Gas Field o Oil FiI~ld • AssAM (INDIA) .. < Z<.~- <- ••0 z 1-- '"••• - ~ Figure 2.6: Natural Gas Fields in Bangiadesh (12) 23 Table 2.6: Gas Fields of Bangladesh (I) Recoverable Net Remarks Sl. Field ' Year GIIP Reserve (proven Recoverable No. , (proven + probable) + probable) Reserve TCF TCF TCF 0.867 0.280 P I Bakhrabad 1969 1.432 1.895 1.077 P 2 Habigonj 1963 3.669 2.529 2.297 P 3 Kailashtila 1962 3.657 1.309 1.114 P 4 Rashidour 1960 2.242 0.266 0.100 P 5 Sylhet 1955 0.444 2.100 0.317 P 6 Titas 1962 4.138 0.126 0.097 P 7 Narshingdi 1990 0.194 0.104 0.081 P 8 Meghna 1990 0.159 0.848 0.757 P 9 Sangu 1996 1.031 0.140 0.125 P 10 Saldanadi 1996 0.200 0.815 0.763 P 11 JalaJabad 1989 1.195 0.167 0.162 P 12 Beanibazar 1981 0.243 0.015 0.015 NP 13 Begumgoni 1977 0.025 0.210 0.210 NP 14 Fenchugoni 1988 0.350 0.468 0.468 NP 15 Kutubdia 1977 0.780 0.333 0.333 NP 16 Shahbazpur 1995 0.514 0.098 0.098 NP 17 Semutang 1969 0.164 2.401 2.401 NP 18 Bibiyana 1998 3.150 0.400 0.400 NP 19 Moulavibazar 1999 0.500 0.268 0.241 PS 20 Chhatak 1959 0.447 0.023 0.002 PS 21 Kamta 1981 0.033 0.125 0.085 PS 22 Feni 1981 0.178 11.42 Total 24.745 15.507 P: Producing, NP: Non-Producing, PS: Production Suspended Table 2.6 shows that the total GIIP and initial recoverable reserve of Bangladesh are 24.745 TCF and 15.51 TCF, respectively. Out of this reserve, 4.07 TCF has been produced already (up to February 2001), and the remaining reserve is 11.42 TCF. These gas fields as shown in Table 2.6 are under the jurisdiction of different gas companies, both government owned and multinationals. There are today five companies in the country producing natural gas. These are: 24 i) Bangladesh Gas Fields limited (BGFCL) ii) Sylhet Gas Fields Limited (SGFL) iii) Bangladesh Petroleum Exploration and Production Co. Ltd. (BAPEX) iv) Shell Bangladesh Exploration and Development B.V. (SHELL) v) UNOCAL Bangladesh Ltd. (UNOCAL) Table 2.7 shows a list of these companies and their production capacities. Table 2.7: Production Capacities of Various Gas Fields (8) Company Gas Total Produc Product Daily Production Production Field Wells mg Capacity Goal December Wells 2000-2001 2001 Bangladesh Titas 14 13 Gas 10.761 3592.206 223.144 Gas Fields MS 13.064 5602.230 408.410 Company HSD 52.255 20431.968 1690.435 Condnst 65.319 26553.517 2175.592 Habi- 10 10 Gas 7.560 2039.802 192.127 gan] Condnst 1.890 655.207 62.524 Bakh- 8 4 Gas 0.962 353.676 30.312 Rabad MS 2.209 2173.294 187.658 HSD 3.313 3534.080 258.029 Condnst 5.522 1747.654 166.298 Salda 2 I Gas 0.420 154.951 12.462 Condnst 1.802 660.056 53.504 Norshi- 1 1 Gas 0.509 176.424 12.755 ngdi Condnst 5.879 2239.480 170.104 MS 2.352 - - HSD 3.527 - - Meghn 1 1 Gas 0.510 156.350 8.438 a Condnst 4.170 1349.897 74.945 Sylhet 7 2 Gas 0.141 53.569 4.744 MS 3.000 690.000 4.788 25 Production Company Gas Total Produc Product Daily Production Field Wells mg Capacity Goal December Wells 2000-2001 2001 5.055 Sylhet Kerosin 0.178 70.087 Gas 72.735 Fields Kailash 4 4 Gas 2.940 886.121 611.260 Company -tilla MS 19.500 6650.739 525.307 Limited HSD 18.500 _5718.689 Condnst 185.500 76446.347 6556.151 Rashid- 7 6 Gas 4.332 914.444 71.880 pur Condnst 34.534 7687.085 567.879 Biani- 2 I Gas 0.992 35.464 7.156 bazar Condnst 97.388 329.392 679.668 114.74 Shell Sangu 6 4 Gas 4.248 1354.933 B.Y. Condnst 7.155 3337.615 314.680 UNO CAL .Talalaba 4 4 Gas 2.832 854.76 73.465 Bangladesh d Condnst - 59212.240 3731.412 Limited - Note: Gas: MMSCMD (million standard cubic meter per day), Petroleum Products: Thousand Liters Shell and UNOCAL are international oil companies (rOCs) operating under Production Sharing Contracts (PSC) while BGFCL, SGFL and BAPEX are subsidiary companies of Petrobangla, the public sector corporation to manage oil and gas resources of the country. Bangladesh Gas Fields Company Limited (BGFCL) owns eight gas fields, namely, Titas, Habigonj, Bakhrabad, Narshindi, Meghna, Begumgonj, Feni and Kamta. The productions from the Kamta and Feni fields are now suspended. The production from the Bakhrabad field is likely to be suspended in near future. The' Begumgonj field has not yet been developed (1) Sylhet Gas Fields Limited (SGFL) owns five gas fields, namely, Haripur (Sylhet), Kailashtilla, Rashidpur, Beanibazar and Chhatak; and one oil field, namely Haripur. The production from the Chhatak gas field and the Haripur oil field is now suspended. BAPEX 26 has been given the operatorship of the Saldanadi, Fenchugonj and Shahbazpur gas fields. It produces gas from Salda Nadi field. Shahbazpur and Fenchugonj fields have not yet been developed. Shell Exploration and Development B.Y. produces from one field, namely, Sangu, which is an offshore operation. It also owns two other fields, namely, Semutung and Kutubdia. Kutubdia is an offshore field (I). UNOCAL Bangladesh Ltd. owns three gas fields, namely, Jalalabad, Maulavibazar and Bibiyana. It produces gas from the Jalalabad field (5) After commencement gas production from Jalalabad and Beanibazar gas field and with the completion of drilling of additional wells at Rashidpur, Habigonj and Titas Gas Fields, it is possible to produce 1325 MMCFD of gas from 66 wells of 12 gas fields. Out of the above amount 630 MMCFD gas can be made available from 6 gas fields of the North- East for North- South pipe line for onward transmission to national gas grid (2) 2.5.3 Present Demand and Supply Scenario Natural gas use as a fuel in Chhatak Cement Factory in 1960 with supply from the Chahatak Gas Field marked its first commercial utilization. It was fed to the first ammonia- urea grass-roots complex, NGFF at Fenchugonj in 1961 (2). Over the years the consumption of natural gas has been increasing and its contributed to the national development increased significantly. Gas production of 24 hours from 12-July-00 to 13-July-OO was 931.262 MMSCF (Daily production report, GTCL, 13-July-OO). In the month on March 2000 the peak production was lOIS MMSCFD (5). The peak production in 2000 (up to September 2000) was 1089 MMSCFD. On September 18,2001 the production was 1042 MMSCFD and the two laCs' contribution was "176 MMSCFD (I). The down stream demand and consumption of natural gas are tabulated in Table 2.8, 2.9, 2.10, 2.11. 27 Table 2.8: Downstream Demand and Consumption of Natural Gas of Jalalabad Gas Franchise Area (JFA) (2) . , , c. . , . . . '. ' . Flow Rate Franchise Area (JFA), greater Svlhet I Kumargaon Power Station 0.55MMCFD 2 Svlhet Pulo and Paper Mills (SPPM) 1.70MMCFD 3 Chatak Cement Factorv 4.00MMCFD 4 Private Sector Cement Factory 17.00MMCFD 5 Ainpur Cement Factory 1.00 MMCFD 6 Industrial 1.50MMCFD 7 Commercial 1.50MMCFD 8 Domestic 6.00MMCFD 9 Power 4.00MMCFD Sub-total 36.75 MMCFD Fenchugoni Area I 90 MW Power Station 17.00MMCFD 2 Shahialal Fertilizer Factory I9.00MMCFD Sub-total 36.00MMCFD Hobigoni and Moulavibazar Areas I Shahiibazar Power Plant 4.00MMCFD 2 Tea Gardens 5.00MMCFD 3 Others I.OOMMCFD Sub-Total 10.00 MMCFD JFA Grand Total 82.75 MMCFD Table 2.9: Downstream Demand and Consumption of Natural Gas of Titas Gas Franchise Area (TF A) (2) ~ , ...... ',I , , FlowRaie'" i", ~':' Ashugonj Area I Ashugonj Power Station 150.00 MMCFD 2 Zia Fertilizer and Chemical Comolex Limited 50.00MMCFD Sub- Total 200.00 MMCFD Ghorasal Area I Palash Urea Fertilizer Factorv 17.00MMCFD 2 Urea Fertilizer Factory, Ghorashal 45.00MMCFD 3 Ghorashal Power Station 150.00 MMCFD Sub- Total 212.00 MMCFD Greater Mvmensing Area I Mymensing, Kisorgonj, Netrokona, Jamalpur and 10.00 MMCFD Sherour. 28 ,~,. 2 Jamuna Fertilizer Faetorv 43.00MMCFD , 3 RPCL Power Plant 25.00MMCFD Sub-Total . 78.00 MMCFD Greater Dhaka Area I Industrial 120.00 MMCFD 2 Commercial 20.00MMCFD 3 Domestic 80.00MMCFD 4 Seasonal 05.00MMCFD Sub-Total 225.00 MMCFD TFA Grand Total 680.00 MMCFD Table 2.10: Downstream Demand and Consumption of Natural Gas of Bakhrabad Franchise Area (BFA) (2) I . Flow Rate Bakhrabad Franchise Area I KAFCO 65.00MMCFD 2 CUFL 50.00MMCFD 3 2X210 MW Rauian Power Plant 90.00MMCFD 4 60 MW and 56 MW Sikalbaha Power Plant 15.00MMCFD 5 KPM 8.00MMCFD 6 Others 40.00MMCFD BFA Total 268.00 MMCFD Table 2.11: Downstream Demand and Consumption of Natural Gas of Western Region Franchise Area (WF A) (2) .. I' Flow Rate Western Franchise Area I 90 MW barge Mounted Power Station 22.00MMCFD 2 71 MW PDB Power Plant 21.00MMCFD WFA Total 43.00MMCFD Total Gas Demand = 1088.75 MMCFD '" 1089 MMSCFD. From above tables, it is clear that the present peak demand of the connected down stream consumer is 1089 MMCFD which can now be met from the current maximum production capacity of 1300 MMCFD after drawing gas from private producer Shell & UNOCAL. The situation has improved with the commencement of production from Beanibazar with effect 29 from May 1999. Obviously it is very rare that all the consumers would ever attain peak concurrently. As such the system peak hovers around 900 to 950 MMCFD which is being met effectively from national gas grid. 2.5.4 Future Demand and Supply Scenario International Oil companies which have already commenced production under PSC will continue their exploration campaign. It is also expected that on achieving significant discovery followed by appraisal and development additional quantity of gas will be available for down stream use. UNOCAL in Surma basin (Block 12, 13 & 14) has already made a significant discovery at Bibyana where two wells have been drilled and a 3-D seismic survey has been carried out for confirming the ultimate recoverable reserve. UNOCAL has also discovered a new gas field at Moulvibazar. Shell, UMIC, REXWOOD are also expected to continue their exploration campaign in their respective blocks. New discoveries will further enhance our gas reserve. Sylhet Gas Fields Ltd. (SGFL) under IDA funded Gas Infrastructure Development Project (GIDP) has completed drilling of 3 wells and installation of required gas treatment plans at Rashidpur Gas Field. Bangladesh Gas Field Company Ltd. (BGFCL) has also implemented drilling of 6 additional wells (3 each at Habiganj and Titas Gas Fields) and work over of some gas wells in these fields. Bangladesh Petroleum Exploration Company (BAPEX) has also completed drilling second well at Salda. These new wells have provided additional information about the reservoir of the respective gas fields and have also increased production by 400-300 MMCFD. On the other hand gas demand is also growing steadily and is expected to grow significantly over the next couple of years as new power plants will come into production in Haripur, Meghnaghat and Western side of the Jamuna river. Government is also planning to set up gas based export oriented fertilizer factories. A Korean EPZ in Chittagong and industrial parks in Sirajganj, Bogura and Ishwardi also being set up if supply of gas and stable power can be ensured. For an urea plant having the production capacity of 5,00,000 tons per year natural gas would require approximately 45 MMCFD. But for adding 100 MW of electricity generation capacity based on natural gas 30 would need about 25 MMCFD additional natural gas. In industrial sector, it will have to consider the supplemental of existing fuel such as furnace oil and diesel oil in industrial installation such as boilers and generators plus new industries to be set up. Replacement of 100,000 ton of Furnace oil per year with equivalent quantity of natural gas means an additional requirement of 12 MMCFD natural gas. By analyzing the demand and supply situation a projection is made here under the Average Base Case Supply/Demand which is shown in Table 2.12. Table 2.12: Average Base Case Supply/Demand (in MMCFD) (2) ., . ,,~ ,.;:- '~!'.;'", •.', ; ' ,~{ ".", . " .. ' , . . ,~ Fisca1'Year , .e. c, • , ' 1998/99 1999/00 2000/01 2001/02 2002/03 2003/04 2004/05 Total Supply 900 1095 1395 1395 1395 1500 1500 Total 920 950 1050 1160 1260 1440 1440 Demand Balance 20 145 345 235 135 60 60 Table 2.12 indicates that there will be a surplus of 345 MMSCFD in 2000/0 I (2). This is primarily due to the development of the Rashidpur Gas Field (3 new wells), Habiganj (3 wells) and Titas (3 wells) coming on stream. Utilization of the additional gas will largely depend on the expansion of the transmission capability of the national gas grid through the completion of Rashid pur- Ashuganj Gas Transmission Loop line. It is important to consider that Bangladesh's natural gas resources are concentrated in a few numbers of big fields (Titas, Habiganj, Rashidpur and Kailashtila) which are at their early stage of development. Of which there are limited field data are available. It is important to conducted regular pressure tests in these fields to keep track of their behavior. A prudent gas supply surplus above average demand should be about 200 MMCFD (2) for the following reasons: This will permit temporary shut-in of one or more well of a field at a time in order to get pressure build up data that are critical for the reservoir management. 31 .P This amount will allow the temporary loss of production from the equivalent of nearly a field without causing many difficulties to the consumers. This amount of surplus should permit taking advantage of the available line pack to better manage deliveries. It should be noted that the supply values in the preceding analysis represent short-term capabilities of the individual fields. These fields are not capable of sustained production for long at those rates. Several fields have peak supply and average supply at the same level. In these cases, the fields are not capable of sustained production above average. The Titas field peak supply and average supply are the same and are at rates lower than current well capacity. More appraisal drilling is needed, as currently planned, along with systematic reservior pressure measurements over time wh'ich will allow engineers and geologists to draw reliable conclusions and to find the strategy to exploited this potential important field. 2.6 Gas Transmission Network The gas transmission Pipeline in Bangladesh have been planned and constructed targeting a particular bulk consumer or potential load center. In the early stage of development of gas sector the grid concept was possibly not visualized. Gas Transmission Company Ltd. And three transmission and distribution companies are responsible for operation and maintenance of these transmission pipelines. Over the years, a national gas line grid has been built and it is connected to lateral and distribution networks. The major gas transmission lines are described in Table 2.13. 32 Table 2.13: Gas Transmission Network (2) , Gas Transmission Pipelines' Controlling Dianieter (incb) Designed. .Design Company and Length (Km) Operating Capacity Pressure (MAOP) Haripur- Fenchugani JGTDCL 8"-25 Km 600 Psi 40MMCFD Tangratilla Chhatak JGTDCL 4"-15 Km 750 Psi 30MMCFD Shahjibazar - Shamshemagar - Juri JGTDCL 6"-45 Km 600 Psi 40MMCFD Valley Titas - Narshindi - Demra TGTDCL 14"-96 Km 1000 Psi 150MMCFD Titas - Narshindi - Joydevpur TGTDCL 16"/14"-91 Km 1000 Psi 170MMCFD Habigani - Ashugani Trunk Line TGTDCL 12"-38 Km 1000 Psi 88MMCFD Beanibazar - Kailashtilla GTCL 20"-18 Km 1135 Psi IIOMMCFD Jalalabad Gas Field- Kailashtilla Unocal 14"-15 Km 1135 Psi 160 MMCFD North-South Gas Transmission GTCL 24"-174Km 1135 Psi 330MMCFD Pipeline Bakhrabad - Demra Pipeline BGSCL 20"-48 Km 1000 Psi 250MMCFD Asguganj - Bakhrabad Gas BGSCL 30"-58 Km 1000 Psi 220MMCFD Transmission Pipeline Salda-Bakhrabad Gas Transmission BGSCL 10"-37 Km 1000 Psi 60MMCFD Pipeline Meghna-Bakhrabad Gas BGSCL 8"-28 Km 1000 Psi 40MMCFD Transmission Pipeline Bakhrabad-Chittagonj Gas BGSCL 24"-174Km 960 Psi 350MMCFD Transmission Pipeline Sangu Gas Transmission Pipeline Shell 20"-45 Km 1135 Psi 240MMCFD The development of Kailashtilla Gas field in early eighties opened avenues for expansion of gas transmission network in Sylhet area. A pipeline was built from the Kailashtilla Gas Field to Chhatak for meeting the demand of that area. Two more important gas transmission network were developed simultaneously following the drilling of 11 wells Beanibazar, Kailashtilla, Rashidpur, Habiganj, Titas , Belabo and Meghna gas fields under second development project. 174 Km. 24" Diameter North-South Pipeline from Kailashtilla- Ashuganj with a parallel 6" Diameter Condensate/NGL pipeline. 33 v( 117 Km. 24" Diameter Brahmaputra Basin Pipeline from Ashuganj to Elenga for delivering gas to greater Mymensing areas, Jamuna Fertilizer Factory at Tarakandi with a future provision for gas supply to the western region of Bangladesh. The emergence of BGSL created revolutionary changes in the economic development activities of Southeast. The power plants, fertilizer factories, paper mill, refinery, steel mill and various other industries of Chittagong region become absolute dependent on gas available from Bakhrabad as well as Feni gas field. But unfortunately poor production strategy led to the dramatic decline of gas production from Bakhrabad Gas field and suspension of gas supply from Feni Gas Field. Under compelling situation due to alarming sand flow and water production the gas production was drastically reduced causing suspension of production of Chittagong Urea Fertilizer Factory and some power plants. This resulted in unbearable load shedding counfrywide. The situation was partially overcome by expediting construction of 58 Km. 30" Diameter Ashuganj to Bakhrabad Gas Transmission Pipeline for diverting the surplus gas from the northern Gas Fields to the Southeast. Subsequently transmission pipelines were also constructed from Meghna Gas Fields to Bakhrabad and Salda Gas Field to Bakhrabad for augmenting the gas supplies to the South-East. For flexibility of gas transmission a 20" gas transmission lateral has been built through Monohordi-Narshigdi-Shiddhirgonj. 18 Km. 20" Beanibazar to Kailashtilla gas transmission pipeline has been constructed and commissioned in April 1999. 15 Km. 14" gas transmission pipeline from Jalalabad gas field to Kailashtilla has also been commissioned in February 1999. Transmission pipeline is also being built along and on either sides of Bangabondhu Jamuna Multipurpose Bridge to supply gas to the Western Region. 34 Chapter 3 PIPESIM 3.1 Introduction PIPESIM for Windows is a user-friendly and multiphase software product developed by Baker Jardine. The PIPES 1M for Windows family of multiphase software consists of: PIPES 1M for Windows-Single Branch, PIPES 1M-Net, PIPESIM-Goal, HoSIM, PlPESIM-FPT, WinGLUE (13). In this study PIPES 1M-Net software is used for network analysis. 3.2 PIPESIM-Net PIPES 1M-Net is a network analysis model extension to PIPESIM for Windows Single Branch. Features of the network model include: unique network solution algorithm to model wells. in large networks, rigorous thermal modeling of all network components, multiple looped pipeline/flow line capability, well inflow performance modeling capabilities, rigorous modeling of gas lifted wells in complex networks, comprehensive pipeline equipment models and gathering and distributing networks. Baker Jardine's PIPES 1M-Net for Windows is a highly sophisticated but user-friendly software package for modelling steady state flow in networks. Combining powerful three phase and thermodynamic analysis methods with rapid convergence algorithms PIPESIM-Net for Windows will give accurate results in the shortest possible time. Furthermore, with PIPES 1M-Net for Windows the user can simulate networks having multiple sources and multiple sinks, flowing compositional mixtures or black oil fluids. And, since PIPESIM-Net for Windows is truly Microsoft Windows compatible, the user enjoy multi-tasking, printer sharing, data exchange and all the other benefits of this operating system. PIPES 1M-Net allows the users to simulate networks flowing just about any single phase or two-phase mixture. If the user wish to get up and running quickly then the user can ("'2->' 35 ""-=( specify different source fluids as a simple black oils. However, the users are also able to enter full compositional data for each source should the user wish. Furthermore, the users are free to enter either global fluid properties or completely different fluids at different sources. 3.3 Black Oil and Compositional Data The difference between black oils and compositional fluids is that the formers are approximations to the latter. Black oil fluids are generic fluid models that can be tuned slightly to match your experimental data, whilst compositional fluids are defined precisely as consisting of quantities of basic constituents (methane, ethane, glycols, water etc.). Using a black oil model often requires less computation time than running a fully compositional model but the user may lose some accuracy. The user may wish, therefore, to run a black oil simulation first and then complete a compositional simulation once satisfactory convergence has been attained. PIPESIM-Net for Windows allows the user to mix black oils or compositional fluids, but the user can not mix black oil with a compositionally specified fluid. Before PIPESIM-Net for Windows can be run using rigorous compositional data, a composition file must be created which contains a component list, quantities and the equation of state (EOS) to be used. This file contains all input information entered by the user and so this file can be restored and modified if necessary. Stream components can be selected fr.om the built-in library, and/or created using the petroleum fraction prediction utility. In reality, oil systems contain many thousands of pure components, consisting of a spectrum of molecules with different carbon numbers and exponentially increasing numbers of different isomers of each. It would be impossible to model the behavior of such systems by explicitly defining the amount of each of these molecules, both because of the excessive computing power needed and the fact that laboratory reports could not possibly supply all this information. Luckily, since the alkane hydrocarbons are non- polar and therefore mutually relatively ideal, lumping them together in the form of a . number of 'pseudo-components' results in fairly accurate phase behavior and physical' property predictions. 36 " ( 3.4 Calibration Data The PIPESIM-Net for Windows toolbox contains all the components that the user will need to view and build and edit a network flow sheet, namely; branches, manifolds, sources and sinks. In PIPESIM-Net the User is able to specify volumetric flow rates at both sources and sinks. The flow rate specification is made in STOCK TANK or STANDARD volume units and is applied to the volumetric flow rate of either the gas or liquid phase depending on whether the User chooses a GAS RATE or a LIQUID RATE. The ability in PIPES 1M-Net to specify Stock Tank flow rates is exceedingly convenient for most Petroleum Industry applications since flow rates of hydrocarbons are normally reported at Stock Tank conditions. However, it is important to remember that specifying flow rate in this way increases the chance of the user providing PIPESIM-Net with a set of unphysical specifications. It is possible for users to specify PIPESIM-Net problems that have no physically reasonable solution. Such a set of specifications is termed a set. of unphysical specifications. If the user supplies such a set then PIPESIM-Net will attempt to find the solution. It will usually fail, however, because its algorithms are designed to look only for physically reasonable solutions. An example of unphysical specifications would be a pressure and flow rate specified at the entrance to a pipeline that causes the fluid to "run-out" of pressure before the outlet of the pipeline. 37 3.5 Model Overview PIPESIM-Net for Windows follows Baker Jardine's PIPES 1M-Net 2.01, which itself was designed as a logical extension to PIPES 1M, a successful point-to-point pipeline simulator. It is a powerful commercial software to solve just about any possible multiphase network, and also retains most of the functionality. of both DOS PIPES 1M and PIPES 1M for Windows. PIPES 1M-Net for Windows allows the user unlimited flexibility with regard to type of problem (13): • unlimited number of source and sink nodes (max. 256 branches) • reverse flow if boundary conditions so dictate • any number of branches connected to a particular node • loop, crossover and recycle specifications • in-line flashing of black oil and compositional streams Hence, it is possible to solve any of the three generic network types, which is shown in Figure 3.1. I) Gathering 2) Distribution 3) Looped Figure 3.1: Types of Network used in PIPESIM-Net 38 3.6 Network Validation All computers modelling software requires a certain amount of physical data before simulation can proceed. PIPES1M-Net for Windows is no different in this respect since the solving of a network requires that values specified for pressure, flow rate and temperature around the system will allow a solution. The criteria that must be satisfied when seeking to model any network with PIPES 1M-Net for Windows can be summarized as follows: The connectivity of the network must be defined The fluid composition at all sources must be defined At least one pressure must be specified somewhere in the system. The total number of boundary conditions must equal the total number of lone nodes. This means that the number of flow, pressure and flow versus pressure curves (inflow performance relationships) that the users specify must equal the number of sources and sinks in the network. 3.7 Flow Correlations Single-phase correlations are, as the name, implies, used by PIPES 1M-Net for Windows for the simulation of pure gas or pure liquid i.e. not multiphase conditions. A number of correlations are available including Moody and AGA (for dry gas). P1PES1M-Net for Windows provides the user with a multitude of multiphase pressure drop and holdup correlations for Horizontal and Vertical Flow Correlations. 3.7.1 Horizontal Flow The following horizontal flow correlations are currently available in P1PES1M-Net for Windows Duns & Ros Beggs and Brill (Original) Beggs and Brill (Revised) Oliemans No Slip Mukherjee and Brill Dukler (AGA and Flanagan) Mukherjee and Brill 39 Swap Angle is an angle (default 45 degrees) above which horizontal flow correlations are used. 3.7.2 Vertical Flow The following vertical flow correlations are currently available 111 P1PES1M-Net for Windows Duns and Ros Beggs and Brill (Original) Baker Jardine (Revised) Orkiszewski Hagedorn and Brown No Slip Govier, Aziz and Fogarasi Mukherjee and Brill Gray 3.7.3 Single Phase Correlations Several single-phase pressure drop correlations are available for both liquid and gas based systems. PIPES 1M will automatically select either the specified two-phase or single-phase correlation depending on the phase behaviour at the particular section in the pipeline. The single-phase correlation is set by default to the MOODY correlation. So, by default if single-phase flow is encountered in the system, the program will automatically switch to the MOODY correlation. The available single-phase correlations are briefly described below: Moody: At Reynolds numbers greater than 2000, the Moody correlation uses the Colebrook-White equation (Moody chart) and at Reynolds numbers less than 2000, assume laminar flow (f=64/Re). (Default). AGA: Known more fully as the AGA Gas correlation. This is the recommended correlation for single-phase gas based systems. Panhandle 'A': Empirical gas based correlation. Limited range of applicability. AGA or Moody correlation recommended. 40 Panhandle 'B': Empirical gas based correlation. Limited range of applicability. AGA or Moody correlation recommended. Weymouth: Empirical gas based correlation. Limited range of applicability. AGA or Moody correlation recommended. In addition to the above, a number of sophisticated new correlations (e.g. mechanistic models) are available as optional extras to PIPES 1M for Windows. These correlations are the result of extensive research and development in multiphase flow laboratories worldwide. 3.8 Convergence PIPES 1M-Net for Windows uses a GNET algorithm to solve all networks. Reaching a solution involves continually estimating and refining a matrix of results for each branch while simultaneously taking into consideration the many sources of discontinuity within the network. These sources of discontinuity' include, dead wells, two phase vertical flow, critical flow, phase changes and flow regime boundaries. By default the tolerance for PIPESIM-Net for Windows simulations is set to 0.01. Mathematically this means that the .simulation will terminate when the root mean square error for pressure at the junction node having the greatest root mean square pressures error is less than 0.01. If the user decrease this value then the user are forcing PIPESIM-Net for Windows to do more calculating and produce more accurate results. PIPESIM-Net for Windows will by default complete a maximum of 100 iterations per simulation. If after 100 iterations no solution meeting the required tolerance has been found then PIPESIM-Net for Windows will stop and display existing results. If the user find that a particular system is not converging then, generally, it is best to relax the tolerance rather than increase the maximum number of iterations. PIPESIM-Net for Windows makes use of convergence techniques that are tuned to suit each individual problem. These routines are based on well-accepted mathematical theorems but modified to allow for the discontinuities that might be generated by different flow correlations, as well as those originating from the problem specification. 41 Chapter 4 GAS TRANSMISSION SYSTEM AND RELATED DATA 4.1 Introduction The gas transmission pipelines in Bangladesh were initially planned and constructed targeting particular bulk consumers or potential load centers. In the early stage of the development of the gas sector, the grid system was possibly not visualized.'But over the years the gas transmission system has expanded considerably and has become complicated. Four Companies of Petrobangla such as Gas Transmission Company Ltd. (GTCL). Titas Gas Transmission and Distribution Company Ltd. (TGTDCL), Bakhrabad Gas System Ltd. (BGSL). Jalalabad Gas Transmission and Distribution System Ltd. (JGTDSL) and two international coinpanies (Unocal Bangladesh Ltd .. Shell Bangladesh Exploration and Development B.V.) are responsible for operation and maintenance of their respective transmission pipelines (Chapter 2). The locations of existing transmission lines (with future extension) were shown in Figure 2.6. 4.2 Network Analysis A geographical breakdown of the demand is a prerequisite to any analysis of a transmission network. In order to reliably cope with the gas transmission constraints and more specifically with the maximum flow rates to transfer through the pipelines, the geographical breakdown must go beyond the traditional split in four areas Tilas Franchise Area (TFA). Bakhrabad Franchise Area (BFA), Jalalabad Franchise Area (JFA). and Western Franchise Area (WFA) which are respectively under the responsibility of TGTDCL, BGSL, JGTDSL, GTCL. The eight areas (Figure 4.1) correspond to a compromise between a significant level of actual demand with a dominant focal point for the demand, meaning that the necessary links (gas pipelines) between areas are reasonably identified (9L Area I: Western zone 42 LEa~ND •. ••••..i'''.'•.•""""""'V' __ ~••••_ •.••••••1I!1"_ eor- ••.• _ •••••.• IP_I TR1PUAA I I N D I A I' G c... ••.__ •.. ,--S.",_",lC'"fU.rv ••••C"'_" .,. •• __ ••••• rs"' ••.•• C •••.•• _"' ••..•. 1I'a__ ••.• C,,"II"" .b •••••••••.'_' o ...... ~. "'': I t \ ,/"'"."~.'I <,; " I ~."""'-;~~oII' I '1.. \ At."'" 1 "\'j') I i ,II 'I '> ( I .!.' to. I 1 "I'\1-<'11'11/'" I pj 1 i "'ulin Y , I .21~"o,,,,o,,, 0 '\ 1 @ ~~. '),,' \1,,1, @ CHI.' TAGONG \~ \ ~ •.,fbi'" ' CD V - ••• e&l ! ! It ,-,~I"I I",;" I, I-" \~ \ 91' '----~-~i\ \, IlA1':GL,\DESI! I I UAY BENGAl I TilE GE()(;RAPIUCAL A;lEAS ; : FOR TIlE GAS SYSTEM D:,Vt:LOPMENT PIAN -C:r Kulubd a ! I I o SO kIT'. Ei£L:::b:~=- ~i Calc \295 Map~,jl \, 00' I "l~ --- I ______.-l_. ~-,---: ..Jr. >; ."'C '.'_-=-_ ..:i Figure 4.1: The Geographical Areas for the Gas System Development Plan (9) 43 / Area 2: Dhaka (the greater Dhaka non-bulk market) Area 3: Meghna (mainly three power stations) Area 4: Bakhrabad-Chittagong (the BFA gas market) Area 5: Ghorasal (mainly the power station and two fertilizer plants) Area 6: Brahmaputra (mainly a fertilizer factory) Area 7: Titas-Ashugonj (mainly the power plant and fertilizer plant) Area 8: Sylhet (the .lFA gas market and the ultimate excess gas resources) The main high-pressure lines of Bangladesh are shown in Figure' 4.2. Possible extensions in Western zone are also shown in Figure 4.3. Network analysis is a complex process. In this study, the gas transmission network is analyzed with the help of PIPES 1M-Net. To simulate the network the following information was required: i) Source temperature, pressure/ flow rate ii) Composition of natural gas of sources iii) Pipe diameter, length, thickness, roughness, ambient temperature iv) Minimum one source/ load pressure The required data is collected from GTCL, .lGTDSL, TGTDCL, and UNOCAL Bangladesh Ltd. All required data are available except pipe thickness and roughness. Therefore, it is assumed that pipe thickness and roughness of pipe are 0.5 inch and 0.0006 respectively. The ambient temperature is changed with the season and place. The . assumed ambient temperature is 25°C because of unavailability of data. The source temperature of Kailashtilla gas field is 110°F and .lalalabad gas field is 83°F. The temperature of other fields varies from 95°F to 110°F. In this simulation, the source temperature of other fields is considered to be 100°F. The Weymouth equation, AGA equation and Moody equation are used to simulate the network. To convergence the simulation, maximum 11 % tolerance is used. But most of the cases the tolerance is below 10 % only. 44 -- ..•...... _------ v TRIPURA ,.. (INDIA) See delalled map 9 I T' 'IT,59kn,J \, r r,- r, \" I oJ " I l- I , I \ \ ComJlIa , J \ ,/ " \ I 24", 115km I " ( I \ '\ \ 1(\ \ I- \ \ \ , \ \ ",' Feni\ lown " 23" -./ R'l\'Ig~------l \,'" SemUlarlg ,/ */ \ ~/M.n~n -' I \ F.:JIl::M ••., '"\ I \, \ \ \ H.'hUItI I 1 I \ I BANGLADESH '8 A Y OF 8 E N G A L GAS TRANSMISSION NETWORK 0 SO ,•. f:r Kutubdia '- Dale 12.95 Map B ",., g, • Figure 4.2: Gas Transmission Network Main High Pressure Lines in Bangladesh (9) 45 , • Possible ~o,ec1in 2010 >-c1 161020"" \::a ~. 62km ..,.(l w o I;: -1 i3 v " TRIPURA 3'" '" ,." o'" ( (INDIAI r.// "z See delailed map "~ ~.••r\ o r ~ I J" I '"0 \ , ..,. o" e;, l h •••.w. \ , '" ", cr: .•.•..r-1 Camilla I \ ./ I \ / \ rn "- x" / • 2.',165km I \ r' \ ( \ ,,r_, ,IBh,!IIam8f8 to Khulna I ,", , '"0'" I(, , \- I l,Jessore , \ " "\,., ,\ / \ " ,.5' Feni Iown ". d' ~ -/;''''{lI~-----7 " N !il, 0 "" < il: ~ &; Semutang .' ~" " tr / \ '" ,,/1c.nIo;::l'Ilwll I...• "3 I, ~ ~ ~F.~, , ;>:l \, =s' 15 >r- , er3." er !l5 tl o ~ 0 f:l ~ "\ I :E z ;c \ "] ~ 3 \. •... ~ 0 ~ ~ 0 = ~ ,r'") " J~f., ( Table 4.1: Chemical Composition of Natural Gas in Different Gas Fields (151 Caloric Specific Remarks SL Name of Chemical Composition of Gas (Volume Percent) Value Gravity No Gas Fields Methane Ethane Propane i-Butane n-Butane High Nitrogen Carbon Gross Composition Dioxide BTU/CFT A UnderBGFCL 1057.73 0.5970 P 1. Bakhrabad 94.20 3.65 0.72 0.20 0.10 0.24 0.42 0.47 0.30 1045.61 0.5833 NP 2. Begumganj 95.46 3.19 0.64 0.17 0.04 0 0 0.60 - 0.6070 P 3. Belabo 94.79 2.49 0.60 0.20 0.15 0.13 0.34 1049.84 0.5782 A 4. Feni 95.71 3.29 0.65 0.15 0.05 0 0 0.15 0.07 1023.91 0.5700 P 5. Habigoni 97.60 1.31 0.27 0.08 0.04 0.06 0.38 1043.13 0.5743 A 6. Kamta 95.36 3.57 0.47 0.09 0 0 0 0.51 0.53 - 0.5910 P 7. Me£hna 95.15 2.83 0.60 0.16 0.09 0.07 0.37 0.11 1031.55 0.5720 P 8. Titas 97.33 1.72 0.35 0.08 0.05 0.06 0.30 1046.21 0.5800 NP 9. Shabbazpur 93.68 3.94 0.71 0.20 0.07 0.04 0.46 0.90 1032.60 0.5700 P 10. Saldanadi 96.32 2.16 0.45 0.12 0.07 0.05 0.27 0.56 B UnderSGFL 1061.95 1.600 P 1. Beanibazar 93.68 3.43 1.10 0.29 1.23 0.17 0.99 0.12 1005.71 0.548 A 2. Chattak 97.90 1.80 0.20 0 0 0 0 0 1043.33 0.5740 NP 3. Fenchu£anj 95.66 2.50 0.63 0.11 0.04 0 0 0.06 0.34 1050.68 0.546 P 4. Haripur 96.63 2.00 0.05 0.14 0.01 0.17 0.66 1056.00 0.5860 P 5. Kailashtilla 95.57 2.70 0.94 0.21 0.20 0.14 0.24 0 1012.00 0.5690 P 6. Rashidour 98.00 1.21 0.24 0 0 0.17 0.02 0.05 C Under International Oil Companies P 1. Jalalabad 93.50 3.50 1.30 0.20 .80 0.20 0.30 0.50 - - 1041.66 0.5860 NP 2. Kutubdia 95.72 2.87 0.57 0 0.31 0 2.36 1061.00 0.5900 P 3. Sangu 94.51 3.17 0.61 0.19 0.07 0.41 2.44 - - NP 4. Semutan£ 96.34 1-....-1.70 0.14 0 0.01 0 0.86 N.B. P = Producing NP = Non-producing A = Abandoned N.B. BAPEX has been given the operator-ship of the Shahbazpur and Salda Nadi fields. 47 '\ ( 4.3 Gas Composition The gases at the wellhead contain largely light hydrocarbons plus CO2, Nz and O2 in small quantity including HzS in trace. The composition of the gases at the wellhead differs from field to field in respect of liquefiable hydrocarbons in particular. The compositions of natural gas of different gas fields are given in Table 4.1. In order to meet the sale gas requirements with respect to composition and other parameters, liquifiable hydrocarbons and water are removed/ recovered in gas processing plants. Table 4.2 lists the specified sale gas composition including other parameters. A typical composition of the sale gas actually delivered is also shown in Table 4.2. The gas processing plants recover about 330 litres of natural gas condensates / liquids per MMSCF gas processed. Table 4.2: Sales Gas Specification ofTitas Franchise Area (II) Date: June,2000 Duration: June 1 to 30 Time: 08:00 Sample Point: Ashugonj Metering Station Manifold Header, Ashugonj, Brahmanbaria Pressure: 57 Barg Temperature: 22.8 0 C Number of Samples: 11024 Average Gas Composition: Minimum Mole % Composition Average Mole % Maximum Mole % C6+ 0.07004 0.15998 0 Propone 0.36262 0.67065 0.21472 i-Butane 0.13491 0.35396 0.03368 n-Butane 0.07349 0.35791 0 Neo-Pentane 45.04450PPM 0.1509 0 i-Pentane 0.04678 0.30706 0 n-Pentane 0.01699 0.18902 0 Nitrogen 0.42046 0.92935 0.34037 Methane 97.2701 98.9522 95.9185 Carbon-Di-Oxide 0.07243 0.22977 0 Ethane 1.52804 2.14383 0 Physical Properties of Supplied Gas: Average Gas Relative Density or S.G. : 0.57456 Average Heating Value, Gross BTU Dry: 1033.94 Heating Value, Net BTU Dry: 932.59 Liquid Hydrocarbon C5+ : 0.05626 GPM 48 4.4 Diameter and Length of Transmission Lines The diameter and length of the transmission pipelines are given in Table 4.3, Table 4.4, Table 4.5, and Table 4.6. Table 4.3: Length and Diameter of Major Transmission Pipelines of JFA (9.15. and 16) SL. From To Length (kIn) Diameter (inch) No. 1 Haripur Khadim 20 8 2 Khadim Sylhet 9 6 3 Khadim Kuchai 10 8 4 Kuchai KS-1 (Manifold) 39 6 5 Kuchai Kailashtilla 13 8 6 Kuchai NGFF 10 8 7 KS-l SPPM Regulator 8 SPPM Inter (Manifold) 105 4 9 SPPM SC-1 (Manifold) 105 6 10 SC-1 CCF Regulator I 1 CCF Inter 0.5 8 12 CCF Tagratilla 19 4 13 Tagratilla Sunamganj 13.5 4 14 Kailashtilla Jalalabad 18 14 15 Kailashtilla Kailash GFI 3.5 14 16 Kailashtilla Beanibazar 18 20 17 Kailashtilla Fenchuganj 27 24 18 Fenchllganj FenPP 5 6 19 Fenchllganj NS-1 (Manifold) 30 24 20 NS-l Rashidpur 39.2 24 21 Rashidpur Bibivana 30 20 22 Rashidpur RashidGf 2 20 23 Rashidpur Habiganj 28 24 24 Habigani HGFI 10 12 25 HGFI SH-I (Manifold) 20 6 26 SH-J HabigTN 5.6 6 27 SH-I Srimangal 10 6 28 Srimangal Shamshemagar 10 6 29 Srimangal Moulavibazar 26 6 30 HGFI Shahjibazar 2.5 8 31 HGFJ Katihata 35 12 32 Katihata Ashllgani 18 12 33 Habigani Ashugani 53 24 49 .. Table 4.4: Length and Diameter of Major Transmission Pipelines ofTFA (9. 16) , SL. From To Length (km) Diameter (inch) No. 34 TitasGF Bbaria I 12 35 BBaria TN-I (Manifold) I 14 36 BBaria TN-2(Manifold) I 16 37 TN-I TN-3(Manifold) 21.1 14 38 TN-2 TN-4(Manifold) 45 16 39 TN-3 Narshindi 30 14 40 TN-4 Narshindi I 16 41 Narshindi Ghorasal 8.4 14 42 Narshindi Demra 32 14 43 Narshindi Shidd 45 20 44 Narshindi BelaboGF 13 8 45 Shidd .T27(Manifold) 10 10 46 J27(Manifold) Demra 10 14 47 Demra Gulshan 32 14 48 Gulshan Joydevour 25 12 49 Joydevpur Elenga 56 10 50 Ashllganj Daulatkandi 9 24 51 Daulatkandi Daulot#(Manifold) 0.1 12 52 Daulatkandi Monohordi 25 24 53 Monohordi Elenga 89 24 54 Monohordi Kishorganj 36 4 55 Monohordi Narshindi 32 20 56 Dhanua Mymen 63.004 12 57 Mymen Netrokona 32.5 6 Table 4.5: Length and Diameter of Major Transmission Pipelines of BFA (9. 16) SL. Length (km) Diameter (inch) No. 58 Ashllganj Bakharabad 57.1 30 59 Bakharabad Falljdar 171.5 24 60 Bakharabad Dewanbag 60 20 61 Sangu Falljdar 49 20 62 Falljdar Chittagoni city 2.5 24 63 Dewanbag Demra 8 20 64 Dewanbag HariPP 1.58 14 65 Bakharabad Salda 35 10 66 Bakharabad Meghna. 28 8 67 Bakharabad BakharabadGF I 20 50 I \. Table 4.6: Length and Diameter of Major Transmission Pipelines of WF A (9. 16) • SL. Length (km) Diameter (inch) No. 68 Elenga .fB1(Manifold) 15 24 69 .fBI .fB2(Manifold) 9 30 70 .fB2 Nolka 15 24 71 Nolka . Sira;gonj 5 20 72 Nolka Bbari 43 20 73 Nolka Ishurdi 65 24 74 Ishurdi Bheramara 25 24 75 Bheramara Kuatia 15 24 76 Kustia Jhenaidha 20 24 77 Jhenaidha Jessore 50 24 78 Jessore Khulna 64 24 51 Chapter 5 STEADY- STATE FLOW OF GAS THROUGH PIPES 5.1 Introduction Pipes provide an economIc means of producing (through tubing or casing) and transporting (via flow lines or pipelines) fluids in large volumes over great distances. They are convenient to fabricate and install, and provide an almost indefinite life span. Because flow is continuous, minimal storage facilities are required at either end (field supply end, and the consumer end). Operating costs are very low, and flow is guaranteed under all conditions of weather, with good control (an installed pipeline can usually handle a wide range of flow rates). There are no spillage or other handling losses. unless the line develops a leak, which can be easily located and fixed for surface lines. The flow of gases through piping systems involves flow in horizontal, inclined, and vertical orientations, and through constrictions such as chokes for flow control. This chapter introduces some basic concepts of horizontal flow types. 5.2 Gas Flow Fundamentals All fluid flow equations are derived tl'om a basic energy balance which, for a stcady state system (no time dependence offlow parameters), can be expressed as: Change in internal energy + Change in kinetic energy + Change in Potential energy + Work done on the fluid + Heat energy added to the fluid - Shaft work done by fluid on the surroundings = 0 Thus, on a unit mass basis, the energy balance for a fluid under steady - state flow. conditions can be written as: dv' g . dU +-+-dz+d(pV)+dQ-dw, = 0 ...... (5.1) . 2g, g, . It is converted into a mechanical energy balance using the well-known thermodynamic relations. For an ideal process. Equation 5.1 becomes: 52 d 2 Vdp+ _V_ + JLdz + df" - dw, = 0 ...... ; ...... (5.2) 2g, g, Neglecting the shaft work ws, and multiplying throughout by the fluid density, p: dp + pdv' +JL pdz + pdf" = 0 ...... (5.3) 2g, g, All the terms in Equation 4.4 have units of pressure. Equation 4.4 can also be written as: ...... (5.4) where 6pl' represents the pressure drop due to friction, and is independent upon the prevailing flow conditions. 5.3 Types of Single-Phase Flow Regimes and Reynolds Number Four types of single-phase flow regimes are possible: laminar, critical, transition and turbulent. Reynolds applied dimensional analysis to flow phenomena, and concluded that the flow regime that will prevail is a function of the following dimensionless group known as the Reynolds number, NR,: upd 4qp N' = inertia - forces --=-- R, V'ISCOUS - fiorces For most practical applications, the Reynolds number for a gas is given by: 20q"Yg ...... (5.5) N R, '" -f.l-d- Where, q" is in mscfd, f.l is in cp and d is in inches. As shown in the Moody fi'iction factor chart, flow regime is related to Reynolds number as follows (171; Flow type N Re, smooth pipes ------ Laminar <2000 Critical 2000-3000 Transition 3000-4000 Turbulent >4000 53 5.4 Pipe Roughness Friction to flow through a pipe is affected by pipe-wall roughness. However, pipe roughness is not easily or directly measurable, and absolute pipe roughness E is, therefore, defined as the mean height of protrusions in uniformly sized, tightly packed sand grains that give the same pressure gradient as the given pipe. This roughness may change with pipe use and exposure to fluids. Some typical values for roughness are shown below (IS!: Types of pipe E Drawn tubing (brass, lead, glass) 0.00006 Aluminum pipe 0.0002 Plastic-lined or sand blasted 0.0002-0.0003 Commercial steel or wrought iron 0.0018 Asphalted cast iron 0.0048 Galvanized iron 0.006 Cast iron 0.0102 Cement-lined 0.012-0.12 Riveted steel 0.036-0.36 Commonly used well tubing and line pipe: New pipe 0.0005-0.0007 12-months old 0.00150 24-months old 0.00175 From dimensional analysis, it has been deduced that relative roughness, the ratio of the absolute roughness and inside pipe diameter, E/d, rather than absolute roughness, affects flow through pipes. 54 5.5 Pressure Drop Calculations The pressure drop over a distance, L, of single-phase flow in a pipe can be obtained by solving the mechanical energy balance equation, which in differential form is (\7) _dp +_ udu +-dzg +_'---.+2!fu'dl dW, =0 (5.6) P g, g, g,d If the fluid is incompressible (p= constant), and there is no shaft work device in the pipeline (a pump, compressor, turbine etc.), this equation is readily integrated to yield g pAu' 2!fpu'dl p,_p, =_ p6.z+--+--- (5.7) g, 2e, g,d for fluid moving from position I to position 2. The three ten11Son the right-hand side are the potential energy (PE), kinetic energy (KE) and frictional contributions to the overall pressure drop, or ~=~~+~u+~ •...: (5.~ 5.5.l The Pressure Drop due to Potential Energy Change (ApPE) API'Eaccounts for the pressure change due to the weight of the column and fluid (the hydrostatic head); it will be zero for flow in a horizontal pipe. From Equation (5.7), the potential energy pressure drop is given by: Apl'!' = -p6.zg ., (5.9) g, 5.5.2 The Pressure Drop due to Kinetic Energy Change (ApKE) ApKEis the pressure drop resulting from a change in the velocity of the fluid between positions I and 2. It will be zero for an incompressible fluid unless the cross-sectional area of the pipe is different at the two positions of interest. From Equation (5.7), API'E=L(Au,)=L(u: -u~)= 8~g2 (~-~J (510) 2g, 2g, J[ g, ld, d, 55 5.5.3 The Frictional Pressure Drop ("'PF) The frictional pressure drop is obtained from the Fanning equation, 21 pu21 "'PF =-~-f (5.11) g,d where, fr is the Fanning friction factor. Usually, the Moody friction factor is used. The friction factor includes, besides roughness, the flow characteristics of the flow regime. It is therefore a function of Reynolds number and relative roughness: where, k is the length of the protrusions on the pipe wall. In laminar flow, the friction factor is a simple function the Reynolds number, 16 If =- (5.12) NRC In turbulent flow, the friction factor depends on both the Reynolds number and the relative pipe roughness. The Fanning friction factor is most commonly obtained from Moody friction factor 1 chart. This chart was generated from the Colebrook-White equation (19 , k = -410g( 3.7~65 + ~r~P;J (5.13) The Colebrook-White equation is implicit in fr, requiring an iterative procedure, such as the Newton-Raphson method, for the solution. An explicit equation for the friction factor with similar accuracy to the Colebrook-White equation is the Chen equation (I"!: S6 5.6 Allowable Working Pressures for Pipes It is desirable to operate a pipe at a high pressure in order to achieve higher throughputs. This is, however, limited by the maximum stress the pipe can handle. The maximum allowable internal working pressure can be detennined using the following ANSI (1976) specification: 2(1-e)SE ...... : (515) Pmax = do - 2(t - c)Y 5.7 Allowable Flow Velocity in Pipes High flow velocities in pipes can cause pipe erosion problems, especially for gases that may have a flow velocity exceeding 70 ft/sec. The velocity at which erosion begins to occur is dependent upon the presence of solid particles, their shape, etc., and is, therefore, difficult to determined precisely. The following equation can be used as a simple approach to this problem (20!; v, =C/ p05 ....•...... (5.16) The gas flow rate at standard conditions for to occur, (qe)", can be obtained as follows: I ]0.5 (q, t = 1,012.435d'lr g~T (5.17) 5.8 Horizontal Flow Many pIpe line equations have been developed from the basic mechanical energy balance (Equation 5.3): pdv' g dp + -- + - pdz + pdf" = 0 (5.18) 2g, g, For simplification above equation, it is required to assume horizontal, steady- state, adiabatic, isothennal flow of gas, with negligible kinetic- energy change. The gas compressibility factor, Z, is made independent of temperature and pressure by using 57 ,, average compressibility factor, Zav, for simplicity. Integrating Equation 5.18 over the pipe length from 0 to L and pressure PI to Pz, we have: 2 _ Rg,T"PI2 )(( 2 - P2 2 ~5 J ...... (5.19) q" - ( 49.9644 P~, r gZ"TfL ln common units, Equation 4.19 becomes: ...... " (5.20) 5.8.1 Non-Iteration Equations for Horizontal Gas Flow i) Weymouth Equation (17) Weymouth proposed the following relationship for friction factor as a function of pipe diameter d in inches: l ...... : (5.21) f = 0.0032/ d " Substituting for f from Equation 5.21 in Equation 5.20: ...... (5.22) This is known as Weymouth for horizontal flow. It is used most often for designing gas transmission systems because it generally maximizes pipe diameter requirements for a given flow rate and pressure. ii) Panhandle (Panhandle A) Equation (17) This equation assumes that fis a function of Reynolds number as follows: f = 0.0768/ N~~14(" ...... :. (5.23) Substituting for f from Equation 4.23 in Equation 5.20: ...... (5.24) The Panhandle A equation is most applicable to large diameter pipelines, at high flow rates. 58 iii) Modified Panhandle (Panhandle B) Equation (17) One of the most widely used equations for long transmission lines, the Panhandle B equation assumes that fis a function of Reynolds number as follows: ...... 025) f ':'0.00359/ N~;~3922 The pipeline flow equation is thus given as follows: I.020( 2 2 JO'510( Jo.490 2.530 q" = 109.364 1;, PI - P2 _1 d 0.020 ••..•••••.•••••.••••..••..•..... (5.26) ( Ps(' J ZCII,1;,J... Y g" f-1g The Panhandle B equation is most applicable to large diameter pipelines, at high values of Reynolds number. iv) AGA Equation (6) American Gas Association (AGA) developed a formula, as computer programs became available to solve this more complex equation. The AGA formula involves the calculation of a transmission factor based on the flow regime and other parameters and takes into account changes in elevation. This equation for calculating pipeline flow is somewhat more complex than above equations but involves the same basic parameters. 0.5 2 2 0.0375GHp;'; PI - P, - ( Z T 1; III f J 25 q=38.77 P. ' F. d' (5.27) ( GTfZ",L bJ 5.8.2 A More Precise Equation for Horizontal Gas Flow (The Clinedinst' Equation)(1?) The Clinedinst equation rigorously accounts for the deviation of natural gas from ideal behavior (an average gas compressibility factor, Z,," is not used in this method), and the dependence of friction factor, f, on Reynolds number and pipe roughness, leading to a trial and error solution scheme. 59 0/ \ .• '\ ...• p Pr1 q" =7.969634p -pcJ:c l[ -- d' lO., [ J,r "l ( p,lZ) dp,-.Lr () p,lZ dp,JO" (5.28) [ p" YgT",Lf This is known as the Clinedinst equation for horizontal flow. 5.9 Gas Flow through Restrictions In several instances in a gas production system, the gas must pass through relatively short restrictions. Chokes, consisting of a metal plate with a small hole to allow flow, are the most common restriction devices used to effect a pressure drop or reduce the rate of flow. The velocity of a fluid flowing through a restriction (orifice, nozzle, or choke) IS expressed as follow (20L v = [1- (d, ~d 2 r]'"[2g(p, - p,)/ p]'" (5.29) Here dl = diameter at the throat of the restriction device, ft d2 = pipe diameter, ft The flow through chokes (and flow restrictions in general) may be of two types: sub- critical and critical. 5.10 Sub-Critical Flow Flow is called sub-critical when the velocity of the gas through the restriction is below the speed of sound in the gas. In the sub-critical flow regime, the flow rate depends upon both the upstream as well as the downstream pressure. Subsurface chokes are usually designed to allow sub-critical flow. The general equation for sub-critical flow through chokes are given below (17): ~ 2 I k f( )21' ( )(k+I)/'] q" = 974.6ICdP,d,,, T k-I tP, / PI - P, / PI (5.30) (Y g I ~ where gas flow rate in Mscfd, pressure in psia, temperature in oR 60 (J ,\ '.\ ,', / . 5.11 Critical Flow Flow is called critical when the velocity of gas through'the restriction is equal to the speed of sound (about 1,100 ft/sec for air) in the gas. The maximum speed at which a pressure effect or disturbance can propagate through a gas cannot exceed the velocity of sound in the gas. Thus, once the speed of sound is attained, further increase in the pressure differential will not increase the pressure at the throat of the choke. Therefore, the flow rate cannot exceed the critical flow rate achieved when the ratio of the downstream pressure P2 to the upstream pressure PI reaches a critical value. The well known choke design equation for critical flow are given below (17): q" = 456.71C"p,d:"&g7; )", : (5.31) 5.12 Flowing Temperature in Horizontal Pipelines For a gIven inflow temperature, T1, and surrounding soil temperature, Ts, the temperature of gas flowing in a pipeline depends upon heat exchanger with the surroundings, given by the overall heat transfer coefficient; the (pressure dependent) Joule-Thomson effect due to pressure. changes caused by friction, and velocity and elevation changes; phase changes (condensation, vaporization) in the gas due to pressure and temperature changes; and energy loss (due to friction) during flow that is converted into heat. Considering thesc factors, Papay (1970) has derived the following equation, assuming steady-state flow of gas, for the temperature TLx at a distance Lx from the pipeline inlet(19l; / r _ [r, +C4 C, - (c,C,)/(C,(C, +C,))]c;,W, ~+~~+~~+~~) (5.3~ I.X (C + CzL fe,e .. c, C,(c, + C,) l x where C2=k/m C, = (Z"2 - z,., )(c pI. - C pv ); L 61 I'-P[, 'z C fldL + (1 - Z )c .lldv ]Z-Z+"' ,-,Q + _2v-v __ ' V + gil / L - __brd 0 T c, L l'I pI. 1'1 1,1" L Lim 1 (2" - 2" Xp, - p,) (c j1dL _ C j1dv) + V, - V, c, L2 pI. pV L Subscripts 1 and 2 indicate the inlet and outlet ends of the pipe, respectively (except in the numbering of the constants C), and subscripts L and V represent liquid and vapor (gas), respectively_ In deriving equation 4.32, Papay (1970) assumed that pressure, flow rate, and phasc- transitions are linear functions of distance from the inlet end of the pipeline. This equation, therefore, is very accurate for short line segments. For the case where phase changes. can be neglected (single-phase flow), Equation 5.32 can be simplified to (17!: J;.x = T;+(1; - r,)e-KL, j1,IV(P,- P')(I_e-K1x )_~(I_e-KL, )_(1" -v, I KL KL~v KL~vj l(v, - v';~")1-e-KL, )+ (v,-2')L, }... (5.33) Ie where K=-- mcpv In equation 5.33, the first two tenns represent the heat exchange with the surroundings, the third ternl represents the Joule-Thomson effect, the fourth term accounts for the elevation changes, and the fifth term accounts for the change in velocity head. The last two terms are small and may be neglected for most practical purposes. If the pressure drop is small, then the temperature drop due to expansion is small, and the third term may also be neglected. Neglecting these terms, Equation 5.33 simplifies to the following familiar fornl (17!: KL T,v =T +(T.,-T)e- , •••..•.••.••....•••.•.••..•.•..••..•.••..•.••..•.• (5.34) _,\ s S 5.13 Steady-State Flow in Pipeline Networks Gas transmission systems often form a connected net, flow through which is almost always transient (unsteady). Most design and operation control problems, however, can be solved reasonably well assuming flow to be steady state. The basic model considers the transmission system to be a pipeline network with two basic elements: nodes and node connecting elements (NCE's). Nodes are defined as the points where a pipe leg 62 ends, or where two or more NCE's join, or where there is an injection or off-take (delivery) of gas. The NCE's include pipe legs, compressor stations, valves, pressure and flow regulators, and underground gas storages. 5.13.1 The Mathematical Models for the Individual NeE's I. High-pressure pIpe leg: The characteristic equation for a high pressure pIpe, according to Equation 5.20, is as follows: P,2 - P, 2 = k,q ' J0.5 or q =I' (, I~P, , (5.35) 2. Low-pressure pipe leg: For a low-pressure pipe leg, with pressure close to atmospheric, Zav'" 1,and P,' - P~ =(PI + P,)(P, - p,)'" 2p,,(PI - p,) (5.36). Thus, the flow relationship simplifies to 2 P, - P, = k,q or q = lP, ;,P2 r (5.37) p"y g (TZ)"fL where k, = 0.015744 2 , •••••.•••••.•••••..••....•••...••••. (5.38) T"d' 3. Compressors: Compressor characteristics vary depending upon the type and the manufacturer. These are usually provided by manufacturer, and can be approximated as follows: p . q = k](p, I p,)" +k, (5.39) where P is the compressor power and kJ, k4, and ks are compressor constants. 4. Pressure regulators: Pressure regulators are similar to chokes, and may be described by the flow relationships for chokes. For sub-critical flow, equation may be used: 63 q =k"p,tr( 1', II', )" x - ( 1',11',. )(X+')I X ]0.5 . (5.40) 5 where k6 = 974.6ICdp,d:JI/(rgd0 [x/(X-I)r' For critical flow, the flow relationship given by equation 5.31 is applicable: q = k,p, (5.41) where k, = 456.7ICdd:;, I(r gT, )05 5. Underground gas reservoirs and storage: q = kg(1',, - 1',,)". (5.42) where 1', = Average reservoir pressure 1', = Wellhead pressure With these relationships for the components of a gas transmission system, a model can be constructed for the system using the analogy of Kirchhoffs laws for the flow of electricity in electrical networks to gas flow in pipeline networks. According to Kirchhoffs first law, the algebraic sum of gas flows entering and leaving any node IS zero: m Lqi = 0 (5.43) ;=1 where m = number ofNCE's meeting at the node q = positive for flow into the node, negative for flow of gas out from the node By Kirchhoffs second law, the algebraic sum of the pressure drops (taken with consistent signs around the loop is zero. Thus, if n is the number of NCE'sin the loop, then for a high-pressure pipeline: :t(1',' - p;)i = 0 (5.44) ;=1 and for a low pressure pipe system: " L(I', - 1',) = 0 (5.45) i"l A pipeline distribution system may either be loopless, or contain one or more loops. The application of the relationships developed so far is described below for each of these system types. 64 5.13.2 Loop Less System A loop less pipe system, defined as one where the NeE's joined by nodes form no closed loops, is shown in Figure 5.1. There are n pipe legs, and n+ I nodes. Gas enters through node 1 and leaves through nodes j, for j=2,3, ..... ,n+ 1. q, q" q, n-] n n+! Node No.: ] 2 3 Pn-t-l Pressure : PI P, P, Pn-l P" Figure 5.1: Loop Less Pipeline System. If one of the terminal pressures, inlet pressure or outlet pressure, is given and the other is to be calculated for a given set of pipe leg parameters and the flow rates into or out of the nodes, then the calculation procedure is quite straightforward. If the inlet pressure, PI, is known, the pressure at any node j can be computed using Equation 5.35 (for high-pressure pipe legs) summed over the applicable pipe legs in the system: i-I , ''''k 2 ...... (5 .46) Pi = P, - L. i'Ii ;=1 wherej = 2, 3, .... , n, n+1 Similarly, if the outlet pressure, Pn+l, is known, Equation 5.47 can be used: " P: = p,~"+ Lki'Ii' (5.47) i==j wherej = n, n-I, ,2, I The problem requires a trial and error type of solution if the maximum throughput through the line at the outlet (node n+1) is desired for a given set of terminal pressures and flow rates into or out of the intermediate nodes. Hain (1968) describes an efficient procedure for solving this problem: ,I' I 65 I \ 0,,'c; \ i \ - \. 1. Guessing the maximum throughput of pipe leg 1, q~'). The superscript (1) indicates that this is a first approximation. 2. Calculating the throughputs for individual pIpe legs, q~') usmg equation 5.46. 3. Using equation 5.47, calculate the outlet pressure for the system, (p~':,) 4. If (p~':,)differs from the given outlet pressure- P'~+I by a value greater than the prescribed tolerance, then correct the throughputs for the individual pipe legs detemlined in step 2 using: q?) = q~') + f\.q (5.48) where f\.q 5. Repeating steps 3 and 4 until convergence within a specified tolerance is reached. In step 4, the correction f\.q becomes more complex for flow systems with a greater variety of NCE's. Hain (1968) gives the following correction for a line containing a compressor station: f\.q = _I(p~'!,)'- P,~",II,: (5.49) [(p~), - (PI'),]; q, + L),q?) where (PI),.' (p,),. = compressor intake and discharge pressures, respectively, psia. 5.13.3 Looped Systems (17) There are two types of looped pipe systems: single-loop (Figure 4.2), and multiple-loop (Figure 5.3). Cross (1936) gave the first solution for low-pressure looped systems, which was later extended to high-pressure systems (Hain, 1968). 66 r: 5.13.3.1 Single-Loop System q, ...... ~ ...... ~ T q, Figure 5.2: Single Looped Systems B c ...... ~ D A ...... •• Figure 5.3: Multiple Looped System 67 The problem requires a trial and error solution scheme. An initial value for the flow rate in pipe leg I is assumed. If this assumed value, q;'), differs from the actual throughput by !'o.q, then by the node law of Equation 5.44 or 5.48 for steady-state flow (17.21): I k;(q~i) + !'o.qM) + !'o.ql= 0 (5.50) i=l where n = number of pipe legs in the single-loop system. Solving equation 5.50 for !'o.q, and assuming that !'o.q« q, we get: - Ik,lq!')ll) !'o.q - '='" (5.51) 22),jq!')\ 1=1 The gas throughputs for the next iteration, q~2) , are computed as before (Equation 5.48): q~2) = q!') +!'o.q (5.52) This procedure is repeated until for iteration k, !'o.qis less than or equal to a specified tolerance. After this successful k-th iteration, the node pressures can be calculated using the relationship (Equation 5.46) for a high-pressure network: i-i . Pi2= P, 2" - ~k,I q,(k)I q,(k) . (5.53) i=l for j= 2, 3, .... , n, n+ 1 where ki for pipe legs are calculated using Equation 5.35 for high-pressure lines. For a low-pressure network, k, for pipe legs are calculated using Equation 5.37, and the node pressures are computed using Equation 5.54: k1 P, = P, - 2),lq) Iq!!) (5.54) for j= 2,3, .... , n, n+1 68 5.13.3.2 Multiple-Loop System Stoner (1969, 1972) has presented an effected method for handling looped networks with all kinds ofNCE's. In this method, the equation of continuity is used to express the flow at each node in the system. The solution to the system of equations is complex, but the method offers the ability to compute any set of unknowns. It thus overcomes the limitation of the Cross method that can only be used to generate throughput or pressure solutions. Illustration for Stoner's method is shown in Figure 5.4. Figure 5.4: Illustration for Stoner's Method (17). For any node j, the continuity equation (Equation 5.43) express the fact that the sum of the inflows and outflows at the node is zero: " F . =" q (5.55) j ~ I,) ;=1 where q i,j is the flow from node i to node j, flows into the node are considered positive, flows out of the node are negative. Fj thus represents the flow imbalance at the node and will be equal to zero when the system is in balance, For example, consider node 2 that receives gas from gas from underground storage (1,2) and pipe leg (10,2), and delivers gas to compressor intake (3,2), and consumer supply attached directly to node 2. Equation 5,55 for node 2 can now be written as: F = ql.2 - q),2 + QIO,2 - q, = 0 (5.56) 2 69 With the substitution of the appropriate NeE equations (from Equations 5.35 through 5.48), Equation 5.56 becomes: F, ~ k p,2 -p 2)" S, -P,-4 . +~~~S(p,20 - p~t~ ,-q ~o (557). ~( l\)( 1,2 _ I I,~ k ( / )" k (k )0,5 l().~ 2 .1 P4 P.I + 5 \ 0.2 where S'j is the sign term that accounts for the flow direction: S'.i = sigll(p, - Pi) = + 1 for Pi 2:Pi = -1 for Pi< Pi Similar equations are written for all the other nodes in the system. Each of the node continuity equations, such as Equation 5.57, can be expressed as follows: FJx"x2,x" ,xJ = 0, for j=l, 2, 3, , n (5.58) This non-linear system of equations can be solved using various iterative techniques on a computer. Stoner (between 1969 to 1972) used the most popular solution method: Newton-Raphson iteration. The values of the unknowns are computed repeatedly, until the values from any two successive steps converge. The values of any unknown at the (k+ 1) th iteration is computed as follows: X~k+l)= X!k) + ,',x)'+') (5.59) " of where ",,_.l,',x. = -F forj. = 1 2 , n L...~ 1.1' " i=1 uXi wherc the derivatives &F/&x, are obtained by differentiating the node continuity equations. The method reqUlres an initial estimate for each of the unknowns, XiO Generally, good initial guesses are required to achieve satisfactory convergence. A standard mathcmatical technique for improving and accelerating convergence is to introduce an accelerating factor, (X,. in the correction (Equation 5.59), as done by Stoner in 1969: xi"') = x!') + ,',xi'+I)a, (5.60) where (x, is computed using the t.Xi for the current and previous steps. Stoner (1969) proposed the following scheme for obtaining (Xi Let A, = ,',x!'+I) / ,',x!'). For the first two iterations, where divergence is most likely to occur, an (Xi = 0.5 is best to use in order to ensure convergence. In subsequent steps, the 70 value of (Xi is determined as below for every other step; for the steps in between, (Xi = 1.0 is used: OJ For Aj ~ -1, = O.SIAjl For-1 OJ = 1.0 + O.SIAjl , For Aj 2: 1, ° =3 Stoner obtained these specifications for (Xi by experimenting with the mathematical model on a computer. Naturally, these are empirical, system-dependent values, and the user may have to do some experimentation to obtain similar or better schemes for the acceleration factor (Xi applicable to the system. 71 Chapter 6 SIMULATION RESULTS 6.1 Introduction The major part of the future energy demand would be met from natural gas and it is estimated that gas demand would reach about 1450 MMSCD (average) and 1700 MMSCFD (maximum) by 2005 and 1900 MMSCFD (avg.) and 2250 MMSCFD (max.)(4) by 2010. In this Chapter,. high-pressure transmission network has been simulated and pressure at different sources, sinks and manifolds are matched with the existing conditions. The existing pipeline capacity is analyzed and the level of capacity utilization is examined. Then different cases have been studied for future prediction. 6.2 Demand-supply Scenario of High-pressure Gas Transmission Lines of Bangladesh Using Current Data The transmission pipeline network compnses of high-pressure trunk gas pipelines, which operate at a pressure greater than 900 psig. Gas production in 24 hours from 12- , July-OO to 13-July-00 was 931 MMSCFD. Out of this, Jalabad franchise area (.lFA), Titas franchise area (TFA), Bakhrabad franchise area (BFA) and Westem region franchise area (WFA) consumed 54, 621, 241 and 15 MMSCFD of gas, respectively. Figure 6.1 shows the present network system. Description of the present network IS given below. 6.2.1 North South Gas Transmission Pipeline (N-S line) The North South pipelines was built under the Projcct Implementation Unit (PIU) of Petrobangla which was then transferred to the Gas Transmission Company Limited (GTCL), now in charge of operating this pipeline. World Bank financed this project. The North South pipeline was commissioned in May 1992 but put in operation in September 1993. It is a 175 km pipelinc of 24" diameter, made of OS' wall thickness API5L grade X56 line pipes. Its origin is at Kailashtilla manifold station and termination point is at Ashugonj metcring station where metering, regulating and fractionation facilities are in place. It was built by SAIPEM (Itally). It transports gas from Kailashtilla 72 _L. KTL234 6B.09 mm,d/d r,;} P: 1090 p,ig ~~odGF: 1092 Psig ~ ~ OO~"'~ c1ld F: 82.54 mmscf/d Jo 'lour~ur: 3. l\tnenPP: 14.~e... NelKono: 200 """' Fef'ilP: 0.00 mmscfld RashidGF: 70.62 mm,d/d P: 1 4) Psig HOF1: 187.9 mmscl/d Nob JB2 JB1 o ~ Dhanua MenthOl' Menifold K8I:ihata D~1~e Sheh;PP: 36.61 mrnsc11d e TN1 10 TN3• • (\) B8ari: ",,",c'" Tltel$GF: 303.2 mmscfld D8Ulot# r ,j ;'rl" N1 06: 5.00 ntnsc1~ ZiOFF:0.0~11d eg, G T8~ BeloboOF 17.14 Salda. . 15.12 rrmsd/d APS: 100,99 mmscffd 16.31 mmsd/d BekhraGF~ o T'.Jrsbo* 8 D hn~ 34.43 mrmlcl/d / 10 ;: ," !F .-. -&...-o-.O-.~O-.e-_._e-_~.. CtgCity:241.2 mmscf/d Bokhro' K"Bopur eto L••••••m Ford J42 _OllO. BEWob P: 1075 Psig P 1006 Plig N16 p 1oIegt-naPP: 0.00 """did P: 106B Psig Han?P: 29.BFi m'ffiicf/d Sl'*JdPS 14.62 rrrnscfJd Figure 6.1: High Pressure Gas Transmission Lines of Bangladesh simulated by Using Current Data () 73 gas field, Jalalabad gas field and Beanibazar gas field ta the inlet .of Narth Sauth pipeline (Kailashtilla manifald statian). Gas alsa carnes from Rashidpur gas field and Habiganj gas field ta the Narth-Sauth line at Rashidpur manifald statian and Habiganj manifald statian respectively. There is na bulk cansumer from Narth-Sauth line except 90 MW Fenchuganj pawer plant, which cansume gas from Fenchuganj manifald statian. The maximum allawable .operating pressure .of the N-S pipeline is 1135 psig, its maximum inlet pressure 1090 psig. And the narmal pressure at Ashuganj is 850 psig. The capacity afthis line is 385 MMSCFD. 6.2.2 Bakhrabad to Chittagong Gas Transmission'Pipeline (B-C line) B-C line is a 174 km lang, 24" diameter pipeline. Its inlet paint is at Bakhrabad manifald statian and .outlet paint is at Faujdarhat city gate statian. There is na bulk cansumer al.ong this line.>Its capacity is 350 MMSCFD. The pressure at Bakhrabad manifald statian is between 850 and 900 psig and with the maximum flaw rate .of 170 MMSCFD at Bakhrabad. The pressure dr.op is abaut 100 psig ta ga ta Chittagang. The gas at Chittagang is distributed in a 350 psig ring main around the city. Mast cansumers there are bulk c.onsumers, pawer plants .orfertilizer fact.ories. The damestic cansumptian is .only 4% .of the tatal. The delivery pressure t.o all pawer and fertilizer plants is 350 psig except the delivery pressure ta KAFCO fertilizer plant in Chittagang, which is .only 120 psig. B-C line is unfartunately limited at ANSI 400. This is inc.onvenient because it limits the pipeline MAOP ta 960 psig but alsa because ANSI 400 valves and fittings are nat easily f.ound an the market and can nat be exchanged with ather gas transmissian campanies which are using ANSI 600 equipment. A cathadic protectian is applied an the pipeline with a negative valtage .of at least 0.85 V between the pipe and a saturated caper- caper sulfate reference electrode, which is satisfactary. 74 6.2.3 Ashugonj to Bakhrabad Gas Transmission Pipeline (A-B line) To create stability in transmission system of Bakhrabad Franchise Area, A-B line is constructed. It has also benefited from the physical integration of the three systems, such as JFA, TFA, and BFA. GTCL is responsible for the operation of the A-B line. This pipeline is 59 km long, 30" diameter, made of APIX52 line pipes with a MAOP of 1000 psig and ANSI 600 ancillaries. A 10m wide right of way was acquired with a IS m wide working area during construction. This line delivers gas from Ashugonj metering station to Bakhrabad manifold station. There is no bulk consumer from this line. Its capacity is 500 MMSCFD. Mc Connel-Dowel of Australia constructed this line. 6.2.4 Bakhrabad to Demra Gas Transmission Pipeline (B-D line) The gas flowing from Ashugonj to Bakhrabad will supplement the short supply from the Bakhrabad gas field to the Chittagong area. To create stability in the transmission system an idle pipeline was constructed to flow gas from Bakhrabad to Demra. It is a 68 km long, 20" diameter pipeline. Its origin is at Bakhrabad manifold station and termination point is at Demra City Gate Station. Haripur power plant receives gas from Dewanbag manifold station of Bakhrabad-Demra line. Its capacity is 250 MMSCFD. The pressure of Bakhrabad-Demra line is smaller than the other transmission lines due to the pressure problem of Bakhrabad gas fields. There are valves in inlet and outlet of Bakhrabad-Demra line for controlling flow as well as pressure in Bakhrabad-Demra line. There is also a by pass line from Bakhrabad manifold station to the point where Bakhrabad gas field connects with the B-D line. A pressure regulator is connected to this by pass line to regulate pressure according to the pressure of Bakhrabad gas field. Even though, Demra City gate station accepts gas from Bakhrabad-Demra line by controlling pressure (using pressure regulator) ofDemra city gate station. Spie-Capag of France completed sub-surface drilling over Meghna River (4700 feet) by Directional Drilling Method. 6.2.5 Ashugonj to Elenga Gas Transmission Pipeline (A-E line) A-E line, which is known as Brahmaputtra Basin line, is a 124 km, 24" diameter pipeline. Its inlet point is at Ashugonj metering station and outlet point is at Elenga 75 manifold station. It delivers gas to Kishoregonj from Monohordi manifold station; Netrokona, Mymenshing power plant from Dhanua manifold station; Sherpur, Jamuna fertilizer factory, Jamalpur from Elenga manifold station. Its capacity is 340 MMSCFD. A-E.line was commissioned in 1991. Spie Capag of France constructed Titas-Elenga Transmission lines. Both Elenga-Tarakandi line (43 km, 12" aD) and Dhanua- Mymenshing line (56 km, 12" aD) were commissioned in 1991. Both Monohordi- Kishoregonj line (35 km, 4" aD) and Tarakandi-Sherpur line (47 km. 8"/6" aD) were commissioned in 1993. 40 km, 8"/6" Mymenshing-Netrokona line was also commissioned in 1993. 6.2.6 Titas-Narsingdi-Demra Gas Transmission Pipeline (T-D line) It is an 81 km long, 14" diameter pipeline. Its capacity is 175 MMSCFD. There are two bulk consumers (Ashugonj power station and Zia fertilizer factory) from this line. Its origin is at Titas gas field and termination point is at Demra city gate station. This line is commissioned in 1968. Mis Society Des Grands Travaux De Marseille (GTH) of France constructs this line. 6.2.7 Titas-Narsingdi-Joydevpnr Gas Transmission Pipeline (T-J line) It is an 82.81 km (46.3Ikm + 36.50km) long, 16"/14" diameter pipeline. Its capacity is 265/220 MMSCFD. Its origin is at Titas gas field and termination point is at Narshindil Joydevpur city gate station. Both Titas-Narshindi line (46.31 km, 16" aD) and Narshindi-Joydevpur line (36 km, 14" aD) were commissioned in 1985. There are two lines between Narshindi city gate station to Ghorasal manifold station. One line is 12 km long, 14" diameter and other line is 12 km long, 16" diameter which is parallel to each other. 12 km, 14" aD Narshingdi-Ghorasalline was commissioned in 1970 and 12 km, 16" aD Narshingdi-Ghorasal line was commissioned in 1999. Ghorasal manifold station is the focal manifold of this line because two fertilizers and one power station receive gas from this manifold. The capacity of Narshingdi to Ghorasal line is 370 MMSCFD. A group of companies are constructed T-J line. The name of the companies are given below: i) Maxwell Engineering Works Ltd. ii) Probash Prokaushali iii) Royal Utilization Services (Pvt.) Ltd. iv) Business King v) Shamsuddin Miah and Associates Ltd. vi) Dawn Construction and Co. Ltd. 6.2.8 Monohordi-Narsingdi-Shiddhirgonj Gas Transmission Pipeline (M-S line) It is a 67 km long, 20" diameter pipeline. Its starting point is Monohordi manifold station and ending is Shiddhirgonj District Regulating station. Shiddhirgonj power station consumes gas from this line. This line is inter connected to 14" Narshingdi- Demra line. Monohordi-Narshingdi line and Narshingdi-Shiddirgonj line were commissioned in 1997 and 1999 respectively. 6.2.9 Western Region Gas Transmission Line It is 70 km long, 24"/30"/24"/20" diameter pipe line. Its ongm is Elenga manifold station and tennination point is Baghabari station. Baghabari power station consumes gas from this line. 6.2.1 0 Network Analysis The network is analyzed by assuming 1092 psig pressure at Ialalabad gas field. The simulated flow rate of Ialalabad gas field is 82.54 MMSCFD that is nearly accurate to the original value (82.66 MMSCFD). Hence the simulation is correct. The simulated results and pressure drop along the transmission lines are tabulated in Appendix 1. The capacity of the North-South pipeline is 335 MMSCFD. The variations of pressure and flow rate with the length are shown in figure 6.2 and 6.3. NOffilally, as a rule of thumb 1 psig pressure drop occurs for 15-km length. From figure 6.2, it is clear that the pressure in North-South line is gradually decreased from 1090 psig to 1077 psig (pressure drop 13 psig) for 174 km. Velocity of gas in Bakhrabad- Demra line (3.36 million fUhr) is greater than the Bakhrabad-Chittagong line (1.59 million fl/hr). Hence the pressure drop in Bakhrabad-Demra line is greater than the Bakhrabad-Chittagong line. 77 1090 1085 OJ i 'iii I I-+--N-S line 0- 1080 I -D- B-C line ~Q) :J I I ({) ''\"~~J::l-_ ! B-D line (() 1075 --~--nf$___ Q) ~ I '0 A-E line Q.. 1070 1065 o 50 100 150 200 Length, Km Figure 6.2: Variation of Pressure along the Major Gas Transmission Lines. 400 1 I o 350 I ! ! I b 300 I ' I I : I , I ~ 250 -+- N-S line ~ 200 ! - I ! I --/lO-- B-C line ~Q) , I I ~ 150 ~ • L_ . I I B-D line ~ 100 A-E line LL 50 I ; I , I I o , , , o 50 100 150 200 Length, Km Figure 6.3: Change ofFlowrate along the Major Gas Transmission Lines. 78 Figure 6.3 shows the variation of flow rate along the transmission lines. In North-South line, first jump of flow rate occurs due to the addition of 70.62 MMSCFD at Rashidpur. The second jump of flow rate occurs due to the addition of 132.24 MMSCFD at Habigonj from Habigonj Gas Field. In Bakhrabad-Chittagong line, jump of flow rate occurs due to the addition of 119.8 MMSCFD of gas at Faujdarhat manifold station from Sangu gas field. In A-E line, 1st jump of flow rate occurs due to the addition of 83.11 MMSCFD gas at Daulatkandi from Daulot# (Manifold station on 16" Titas- Narshingdi line). At Monohordi point, a sharp decrease in flow rate is observed due to 158.8 MMSCFD of gas is delivered to Narshindi manifold station and Kishoregonj area from this point. On July 12, 2000, the inlet and outlet pressures of North-South line were 1090 psig and 915 psig, respectively; but the simulated pressures in this line were 1090 psig and Ion psig respectively. Therefore, a 17.6 % error in pressure was observed at Ashugonj metering station. Demra, Chittagong, Bakhrabad, Elenga, Narshingdi, Ghorasal and other important points also showed unacceptable pressure differences. Variation of liquid holdup along the North-South pipeline is shown in Figure 6.4. At Kailashtilla manifold station, the liquid holdup is 52.7% only. This value is become 53.9 % up to Rashidpur manifold station. After Rashidpur manifold station, liquid holdup is decreased due to the addition of dry gas from Rashidpur gas field at Rashidpur manifold station. At Habigonj manifold station, liquid holdup is 44.8% only. After this point, this value decreases again due to the addition of dry gas from Habigonj gas field at Habigonj manifolld station. At Ashugonj metering station, liquid holdup increases and becomes 25.9 % due to pressure drop. 79 60 50 o;,R ci 40 :::l -0 , , 30 :--+-- N-S line i Io -0 'S 20 0- :.::J 10 o o 50 100 150 200 Length, km Figure 6.4: Variation of Liquid Holdup along the North-South Pipeline If the same simulation is revised with the known pressure at Kailashtil1a manifold station (1090 psig) and Ashugonj metering station (915 psi g); the simulated pressure at other manifold station nearly matches with the measured data. Figure 6.5 shows the present scenario. Good pressure match is observed at different nodes and delivery points, which is shown in Table 6.1. The percentage of error at different nodes and manifolds are very low (Table 6.1). Figure 6.6 shows the comparison of calculated pressure to the measured pressure of North-South line. There is almost negligible pressure error is observed at North-South line. But from Figure 6.7, it is observed that the pressure drop in Bakhrabad-Demra line is greater than the Bakhrabad-Chittagong line. Since the velocity of gas in Bakhrabad-Del11ra line is greater than the Bakhrabad- Chittagong line, therefore, the pressure drop in Bakhrabad-Demra line is greater than the Bakhrabad-Chittagong line. Even through, the pressure drop in North-South line is 174 psig. A significant pressure drop and flow constraints is also observed at Ashugonj- Bakhrabad line and Narshindi-Demra line. Therefore, it is required to find out the reason of the above situation. 80 KTL1~KTL234f12 604 68 08£ ': P 1090 PStg ~ ~mmS1U~enpp ~ ~ mmscf/d mmscf/d JalaGE. N98: 4.00 mmscfld Ja~pur ~ LX NetKona: ~ /P1090P"g j ~men DMymen: 2.00. mmscf fJ N61 - _...@KTdl~ 1\1111 ~.,... 88azer 0 00 mmscl/d FenPP: O.OOmmscf/d Sylhet: 17.28 mmscf/d P: 864.98 Psig A.c i:n", P: 862.53 E'.,.r,g,~.Nr:,bine Dhanua HGf: 18790 Psig mmscf/d NoIlka JB2 lani10ld Kalihata DGhoraFF: 43.20 mmsc&Ro~aFF ShahjiPP: 36.61 mmscf/d ~ TN1 BBeri: 13.19 mmscf/d T TitasGF: 303 mmscl/d DJDevpur: 6.00 mmsc1fd N108: 916.00 psig .".-8 line BeleboGF: 16.31 mmscf/d N106: 5.00 mmscf/d MeghnaG ZiaFF: 0,00 m~f~i/d100.99 mmscf/d DGulshen: 52.00 mmscfll ~fl B.D line Bakhra Demri MegilePP 8.[ line DDemre: 87.00 P: 750.01 P: 891.17 Psig KuBapur SIJre mmscf/d Psig Laksham Feni J42 N107: 5.00 mmscf/d MSharai Barab Fa~dar ShiddPS: 14.62 m~~~rrd 29.86 mmscf/d MegPP: 0.00 mmscf/d CtgCity: 750.00 psig SanguOF: 119.8 mmscl/d Figure 6.5: Demand-supply Scenario of High-pressure gas transmission lines of Bangladesh modified by known pressure at Ashugonj. o 8 81 .Ql 1100 C/) 0.. 1050 ~---.._.--.---.. --+- Calculated . ~~---~~--- ::l~ 1000 C/) -_ Measured C/) 950 I ~ 0.. 900 o 50 100 150 200 Length, Km Figure 6.6: Calculated and Measured Pressure along the N-S Line. 1150 1100 ------.-~ .. --._._.--.~.--.~._~-~.~--~--._-~-~--- .. 1050 .~ 1000 c. --+- N-S line 950 ~ --B-C line ::l C/) 900 ,1-- C/) I B-D line ~ 850 ---.- - - - - .. - _....~~E line 0.. 800 -~----.-.---- 750 -----.----1 700 o 50 100 150 200 Length,Km Figure 6.7: Variation of Pressure along the Major Gas Transmission Lines after Modification 82 Table 6.1: Comparison of Simulated Pressure to the Measured Pressure Node/ Delivery Point Measured Calculated % Pressure (psig) Pressure (Psig) Error APS 860 873.11 0.02 GhorasalPP 685 655.55 0.04 HaripurPP 700 761.61 0.09 RPCL(PP) 830 855.71 0.03 GhorasalFF 704 793.82 0.13 Bakhrabad 867.3 891.17 0.03 Ashugonj 915.81 915.79 0.00 Demra 710 750.01 0.06 Chittagonj 712.5 700 0.02 Kailashtilla 1090.74 1090 0.00 Rashidpur 1046.64 1035 0.01 Habigonj 1020.41 1005 0.02 The reasons of flow constraints are given below: i) Due to the condensate accumulation in transmission lines, the effective diameter of the lines may get reduccd and flow constraint may arise. ii) Due to the corrosion of pipe, the roughness of the pipe may increase. Hence pressure drop through the line will increase. iii) Un-authorized delivery line (which is common problem in Bangladesh) can exist in the transmission system. Hence pressure drop may arise. Variations between simulated results and measured results might be due to the system loss in transmission system. During 12-lul-00 to 13-lul-00, the production of gas was 931 MMSCFD but consumption was only 905 MMSCFD. Therefore, 26 MMSCFD of gas are lost during transmission and distribution system. iv) During the simulation pressure losses due to valves and fittings are over looked. v) There are two-flow controllers, one the Ashugonj to Elenga line and the other on the Ashugonj to Bakhrabad line that are over looked during simulation due to the Software limitations. The flow controllers are used to control flow of A-B line and A-E line. The diameter of A-B line is 83 greater than the A-E line. Hence A-B line can carry large volume of gas than A-E line. But practically this was not happened due to the constraint ofB-D line. Therefore, A-B line carry gas depends on the demand ofB-C line and B-D line that is controlled by flow controller. vi) Pressure drop occurs in every metering, regulating, condensate separating station that is also over looked during simulation due to Software limitation. As a result of condensate accumulation the effective diameter of the North-South line may get reduced and pressure drop occurs in every metering, regulating, condensate separating station. To investigate these point, the network has been simulated by reducing the diameter of the North-South line (assumed diameter of North-South line is 22" OD), installing choke at the inlet of Ashugonj-Elenga line, Bakhrabad-Chittagong line and Bakhrabad-Demra line of bean size 14.5", the measured pressure in transmission lines, except Bakhrabad-Demra line, turned out to be close to the simulated pressure. Figure 6.8 shows the variation of pressure along the major gas transmission lines. The inlet pressure of the North-South line is 1090 psig and the outlet pressure is 928 psig. On this day, the measured pressure of Ashugonj metering station was 915 psig. Therefore, it can be said that the diameters of the transmission lines have been reduced. 1150 1100 .gJ 1050 (/) -+- N-S line D.. 1000 --A-E line :J~ 950 (/) .w. B-D line (/) 900 ... - ..,.....--.:.-. ~ B-C line D.. 850 800 750 o 50 100 150 200 Length, km Figure 6.8: Variation of Pressure along the Major Gas Transmission Lines. 84 The outlet pressure of the Bakhrabad-Demra line is 784 psig that is larger than the measured pressure. The measured pressure of Bakhrabad-Demra line varies from 550 psig to 600 psig that depend on the pressure of Bakhrabad gas field. The measured pressure .of Bakhrabad gas field was 600 psig. In the next simulation, attempts were made to match pressure at Bakhrabad gas field. 6.3 Modification of Network by Using Known Pressure at Bakhrabad Gas Field From the previous study, it is clear that the pressure at Bakhrabad gas field is 891 psig. But it is impossible for this field to produce 35 MMSCFD at this pressure. Current producing pressure of this field is 600 psig only. At present, Bakhrabad gas field is connected to the network system by reducing the pressure of Bakhrabad-Demra line. To reduce pre~sure of Bakhrabad-Demra line, two valves and pressure regulator are used which are described before. Currently Bakhrabad-Demra line is the focal line of the transmission lines, which is treated as an idle line, which means that the volume it transports is much lower than its capacity. Bakhrabad-Demra line transport gas to Demra city gate station and Haripur power station. But pressure in Bakhrabad-Demra line is lower than the Demra city gate station. Therefore, it is facing serious problems to transport gas parallel to the other transmission lines. Low pressure at the Bakhrabad gas field has created this problem because the field producil}g pressure is 600 psig. It is apprehended that if production of Bakhrabad gas field is stopped, the well would die due to accumulation of sand and water. There are valves in inlet and outlet of Bakhrabad-Demra line for controlling flow as well as pressure in Bakhrabad-Demra line. There is also a by pass line from Bakhrabad manifold station to the point where Bakhrabad gas field connects with the B- D line. A pressure regulator is connected to this by pass line to regulate pressure according to the pressure of Bakhrabad gas field. Even though, Demra City gate station accepts gas from Bakhrabad-Demra line by controlling pressure of Demra city gate station using pressure regulator. When Demra city gate station accept gas from ~, Bakhrabad-Demra line, delivery pressure from Demra City gate station decreases drastically. The present simulation (Figure 6.9) is simulated by reducing the diameter of r-'- .~-"" ( ~ 85 e, - / North-South line, taking a separator at Ashugonj, installing a choke of bean size OS' in the inlet of Bakhrabad-Demra line and blocking reverse flow from Demra city gate station. Assuming 625 psig pressure at Bakhrabad gas field, the scenario is simulated. The calculated flow rate of this field is 34.32 MMSCFD that is equal to the delivered flow rate, 34.43 MMSCFD. The simulated results are shown in Appendix 3. The variation of pressure with length are given in Figure 6.10. The outlet pressure of North-South line is 917 psig that is close to measured pressure at Ashugonj (915 psig). The measured pressure of Bakhrabad-Demra line varies from 550 psig to 600 psig that depend on the pressure of Bakhrabad gas field. After simulation, the calculated pressure along this line varies from 907 psig to 619 psig. Figure 6.11 shows the variation of flow rate along major transmission lines modified by using known pressure (625 psig) at Bakhrabad gas field. After Dewanbag manifold station, the flow rate of Bakhrabad- Demra line is reduced and become zero because the outlet pressure of Bakhrabad- Demra line is smaller than the Demra city gate station. Effect of separator at the end of North-South line is shown in Figure 6.12. At Kailashtilla manifold station, the liquid holdup is 40% only. This value is become 41.4 % up to Rashidpur manifold station. After Rashidpur manifold station, liquid holdup decreases due to the addition of dry gas from Rashidpur gas field at Rashidpur manifold station. At Habigonj manifold station, liquid holdup is 32.6% only. After this point, this value decreases again due to the addition of dry gas from Habigonj gas field to Habigonj manifolld station. At Ashugonj metering station, liquid holdup decreases and becomes 0.05 % due to separation of liquid from gas by using 90% efficient separator. 86 HOliiF: N98 3.47 ~LX~KOO. """",lid 'SOMj FenGanj N.S line FenPP F: 70.62 fIlIllOcfld Rashidp Sylhel : 17.28 educed Die. of N.S line is 22" • .e' rml$cf/d JB1 \'.':;,!ern ,eQK,r, HalJigan] ~,.~r';;r",I~_:iQt., lin", Manifold KatihEia Manlf ShotjlP!' Separator 36.61 rrrnocfld T [i :I'-,'~ Tlt•.oF 303.00 rrrn,cfld T.J line o Nl06 : 100.99 fIlIllOcfld B.D fine E-Cnre 'ewnbog 8""lYobadlI KuB"""'S-". L.I"il_'~enI' Choke Be8"l Size 0.5" .142 _.. ea., ~da QgCIy P: 795.2 P,;g Nl07 Me!1'P ShId'S - SnJuGf' Figure 6.9: Demand-Supply Scenario of High Pressure Gas Transmission Lines modified by Known Pressure at Bakhrabad Gas Field 87 ." Q 1200 - 1100--- -+-N-S line --A-E line B-D line B-C line 50 100 150 200 Length, km Figure 6.10: Variation of Pressure along Major Transmission Lines modified by Using Known Pressure atEakhrabad Gas Field 400 o 350 ~ 300 (fJ -+-N-S line :2 250 - --A-E line :2. 200 2 B-D line ~ 150 B-C line ~ 1~~ t=~~=----t=-----~-~-~-~- ~--~-=----- ol---~- o 50 100 150 200 Length, km ------_._------_.--- -~----.-.------_._--_.- ---~ --~ , \ Figure 6.11: Variation of Flow Rate along Major Transmission Lines mod:ified-by Using 'l " Known Pressure at Bakhrabad Gas Field \ ''"''~ , , '. ' n '- --' 88 45 . 40. -~----- ._- ...-..- .. ?f2. 35 .---~-.- ... ci ::J 30 -0 25 . 1 a -+- N-S line I 20 -.-~--.._.. l ~------0 .S 15 . CT ::i 10-- 5.----- o o 50 100 150 200 Length, km Figure 6.12: Effect of Separator at the End of North-South Line 89 ,i 6.4 Modification of Network by Setting up a Compressor Station at Bakhrabad Gas Field The pressure of Bakhrabad gas field is decreasing day by day. Current producing pressure of this field is 600 psig (year 2000). Bakhrabad-Demra line accepts gas from Bakhrabad manifold station by reducing and regulating pressure of this line. This is possible by setting valves at the inlet and out let of Bakhrabad-Demra line. There is also a by pass line from Bakhrabad manifold station to the point where Bakhrabad gas field connects with the B-D line. A pressure regulator is connected to this by pass line to regulate pressure according to the pressure of Bakhrabad gas field. This special arrangement is taken only for accepting gas from Bakhrabad gas field. At Demra city gate station, the pressure is regulated according to inlet pressure with pressure-regulator. To connect Bakhrabad gas field with the transmission system without reducing the pressure of B-D line, a compressor station need to set up at Bakhrabad gas field. To investigate this point, setting up a compressor (700 hp, 70% efficiency) at Bakhrabad gas field simulates the scenario (Figure 6.13). The simulated results are shown in Appendix 4. The variation of pressure and flowrate with length are given in Figure 6.14 and 6.15. The inlet pressure to the N-S pipeline is 1090 psig. If a 70 % efficient compressor of 700 hp is set up at Bakhrabad, the pressure increase to 846 psig which is close to the Bakhrabad-Demra transmission line. Figure 6.16 shows the effect on transmission system after setting up a compressor at Bakhrabad gas field. Therefore, no significant unreality in pressure drop is observed in the transmission lines. r (, 90 ~ ~, 3. MmenPP: 14.88 ,,... NelKana: 2. J, lipur ~ OO~~ 00tTYnsc1Jd N61 ~/ .J')N112 BBazarGF:0.00 mmscfld SeJanj: ~ar; -0- -@ .-0' N4 (;) FenPP: 0.00 rnnsc11d ~ ,.:\.E fine ~st1idP RashldGF --~---'tt'l__ Sylhet: 17 .28 mlTlScfld ' . J82-. ---o--~_~ N103 5.00 mmsOf/d '.JJ,:;.~~~:r, ~;:'r-_~' Dhanua Morl('nor -0-- __..., linE: Mani101d Kal:ihala Menlt Shl:lt1JIPP: 36.61 nrnsctJd ell,_. ,.hFF: 12.8""'$01'" (;) lN3 TN1. C~. 0 e N~r$rll'"lgdl ~JId---O- , TilasGF: 303.2 -.--o-----~---- O\e mmsdd , Issl .r ------0------Q). .. -. es'---V--O NB7 T ".j "n.; NSf' N106: 5.00 ITIfTlsc11d OhoroPP:~~~Ctld Of'" Tarabo~ APS: 100.99 mmscfld 428.04 msm31d37.76 C o hoob"" o 0 3.i: lint:' 0-. .0-.0-.0 ..•--0- .• _0--.__0-_ Kl&pu' 8ijro lol HoriPP: 29.66 "JIml'P Figure 6.14: Variation of Pressure along Major Gas Transmission Lines after setting up a Compressor Station at Bakhrabad Gas Field 400 0 u.. 350 0 (f) 300 -+- N-S line ~ 250 ~ -11--- A-E line 200 OJ B-D line ro 150 -'- B-C line ;;: 100 0 u.. 50 0 o 50 100 150 200 Length, km Figure 6.15: Change of Flow Rate along Major Gas Transmission Lines after setting up a Compressor Station at Bakhrabad Gas Field 92 -----~._---_._-~------ 1000 - .2' ------(/) 800 a.. __ Compressor at 600 ------BGF, HP=700. 400 ------Efficiency=70% . ~_._-_.._--~- .- 200 ------o o 0.5 1 1.5 Length. ft ------~------_.------ Figure 6.16: Effect on Transmission System after Setting up a Compressor at Bakhrabad Gas Field 6.5 Gas Supply- Demand Scenario of High Pressure Transmission Line at Maximum Load The demand of gas is increasing day by day in power, fertilizer, industrial and domestic sectors. To meet this demand, it is required to produce gas from the fields at desired capacity. If the proposed power plants come into production and all fertilizer and power plants operate at their peak production, the consumption of gas will be 1496 MMSCFD. Then the capacity of N-S pipeline will have to be 696 MMSCFD. Presently this line is carrying gas at a rate of 400 MMSCFD. Using maximum load at all delivery points and setting proposed power plants does the present simulation. The network is shown in Figure 6.17. The simulated results are tabulated in Appendix 5. The variations of pressure and flow rate along the major transmission lines are shown in Figures 6.18 and 6.19. The capacity of North-South pipeline is 696 MMSCFD. But the pressure at inlet point of North-South pipeline is 1312 psig, which is much above the design pressures (l090 psi g). The pressure drop in this line is 536 psig that is also very high. It is clear that the pressure drops in North-South line are greater than the recommended pressure drop. Though the pressure drops in the other transmission lines are acceptable, many important points experience shortage of pressure. This serious pressure drop of North-South line is the indication of inability of the pipeline to carry C 93 Khodm A 6.00 . 3.00 1M'lSC1/d , NetKona: 2.00 mmscfA::l mmtd/d 135000 P3IlI -~~LX ""'"'" "" ..r , 311. 9 P$ig . N111 KTile K"""; M""", o..l'lTDSL: 78.00 11m solrt 40DD rnrnsc11d OOll%lIr.35.00 mmscf/d a~ , 20.00 IMlScl/d N' FerilP: 20.00 I1lITlSCfA::l N•••• Rashk:lOF:o 161100 " tnrl'lSef/d K_. Shetdf'P: 35.00 rrrnsc1'A::I Tte:sGF: 300.00 IlYY'IJd/d SoGaon ..,. S.C line •••••••••• ,..• .142 ""','" ...., ShidlPS:40.001mISc1~ 7000 lTrf'lItI!6dS: 2.001MlSCf~ 90110rrmsc1.t1 . • P:769 p,;, Figure 6.17: Gas Demand-Supply Scenario of High Pressure Transmission Line at Maximum Load ~: 160.00rrJl'lSCf,ld 94 \I'. expected flow rate. Therefore, it is required to increase the carrying capacity of North- South pipeline at desired pressure to remove the constraint of transmission system. --~-----_._------_._----_._------ 1400 1300 .------.~ 1200 -----. - - -.----.------.---..--- ___ N-S line a. 1100 __ B-C line :J~ 1000 B-D line ~ 900 .--.-::= -~~•••~=-.:.- A-E line £ 800 'I', _11----_ 700 ------'1 . "a=_------600 .-- o 50 100 150 200 I Length, Km I ------_.------_. Figure 6.18: The variations of Pressure along the Major Transmission Lines modified by Maximum Load 800 700 ------._---- 0 ---_.------LL 600 () =-..=-N~s-lin-~11 CJ) 500 ------~ -lIl-----B-C linel! ~ 400 (]) I B-D line I C1l -- --_. -~ 300 -I __.A -~J.!~.1 ~ l I 0 • ..__-." - - 200 .~~~-- u:: II 100 ._------0 o 50 100 150 200 Length, Km Figure 6.19: Change of Flow Rate along the Major Transmission Lines modified by Maximum Load 95 6.6 Modified Network Using Rashidpur-Ashugonj Loop Line Petrobanglal GTCL intend to expand the transmission capacity of the existing 175 kIn 24" OD Kailashtilla to Ashugonj (North-South) gas transmission pipeline from 330 MMSCFD to 755 MMCFD by constructing 30" OD loop line between Rashidpur and Ashugonj. The proposed pipeline will be more or less parallel to the existing 24" OD North-South pipeline. Considering the projected downstream demand and upstream supply potential from the sources it has been planned to implement the project in two phases. Phase I i.e. 47 km section extending from Habigonj gas field to Ashugonj metering station of GTCL is scheduled to be commissioned by 30th June 2001 to transport 230-250 MMSCFD gas from Habigonj and Titas gas field (Khatihata). Phase II i.e. 35 km section extending from Rashidpur-Habigonj gas field is scheduled to be commissioned by 30th June 2002 (12) To overcome the constraints of N-S pipeline, construction of 82 km 30" OD Rashidpur- Ashugonj loop line is required. Figure 6.20 shows the loop line with provision for a back-up manifold station a Habigonj and at other two suitable locations. Titas (Khatihata) well is connected to this loop line. The simulated results are tabulated in Appendix 6. The variations of pressure with the length are shown in Fig!1re 6.21. The capacity of North-South pipeline with Rashidpur-Ashugonj loop line is 850 MMSCFD. The inlet pressure to the North-South pipeline is 1091 psig that is near about the design pressure (1090 psig). The pressure drop in Bakhrabad-Chittagong line is greater than the Bakhrabad-Demra line because the velocity of gas in Bakhrabad-Chittagong line is greater than the Bakhrabad-Demra line. The changes of flow rate along the major transmission lines are shown in Figure 6.22. In North-South line, up to Rashidpur the flow rate is 268.51 MMSCFD. At Rashidpur point, Bibyana gas field (assume flow rate 100 MMSCFD) and Rashidpur gas field will delivered 280 MMSCFD of gas. From Rashidpur point, 56.73 MMSCFD gas will pass through North-South line and 491.73 MMSCFD gas will pass through Rashidpur-Ashugonj loop line. At Habigonj point 211.17 MMSCFD of gas will be added to the North-South line from Habigonj gas field. After Habigonj point, the flow rate of gas through North-South line is 267.9 MMSCFD. 96 The Khati well of Titas will deliver 90 MMSCFD of gas to the Rashidpur-Ashugonj loop line. Therefore, total carrying capacity of Rashidpur-Ashugonj loop line is 582 MMSCFD. The jump of flow rate at Faujdarhat point is observed due to delivery of 160 MMSCFD of gas from the Sangu gas field. In Ashgonj-Elenga line, the first jump of flow rate occurs due to the addition of 57.94 MMSCFD gas at Daulatkandi from Daulot# (a manifold on T-J line). At Monohordi point, a sharp decrease in flow rate is observed due to 173.18 MMSCFD of gas is delivered from this point. Assuming 950-psig pressures at Ashugonj (normal pressure at Ashugonj), the simulated 'result does not show any significant pressure change downstream of Ashugonj. Figure 6.23 shows the scenario. The simulated results are tabulated in Appendix 7. The graphical representations of the simulated results are shown in Figure 6.24. 97 . Io "-.-, ~ Aerour ~~ ISlpur LX - \i:l!!? IIISl Nll1 laGanj Sylhel: 76 mmscfld P: 1064 P'ig IKisOanj -0-.0"0- 'Elenge o Dh••.•.•• e 40 mm,clld Monohoe Nl03 DG~FF T.J ,in~ 8-0 !ine P,ig 0 o.C I!re 'ewnbag Baktra# KuBepUr 88Ya Lakshern Fenl P:1074 P'ig J42 MSher~.b ctgCly Q: 312.01 mmsclld N76 . P: 1063 P,ig HariPP: MegPP 160 """,clld -SonguGI' SHddPS : 40 mmscfld Figure 6.20: Demand-Supply Scenario of High Pressure Gas Transmission Lines modified Network by Using R-A Loop Line 98 :> , " ._------_._--~-_._. - ..... ~._---~-_._~.------~----- 1095 1090 ,------.~ 1085 --- N-S line 0... --B-C line 1080 ~ ,. B-D line ,,------_.------eniil 1075 -u- _ A-E line £ 107.0 ___ R-A loop line 1065 1060 o 50 100 150 200 Lrength, Km Figure 6.21: The Variations of Pressure with the Length after modified by Rashidpur- Ashugonj Loop Line i 700 .. ------...... ----- .. .. -- - 600 ~ (" --_._- .. .. 0 500 - .. - ...... 1 ---- LL __ N-S line 0 en .. :2 - .. . - -- --.••- B -C lin e :2 400 .,; I .. B-D line ...... ~. -'"~ 300 - ..- --~ ;: _'_.' A -_EJi_n~_.J .Q . ...------_.__ LL 200 .. ------1-- '-'-- --- , .. - "'" ... 100 --,. _. .- _------_.- ~~ 0 . a 50 100 150 200 Len 9 th, K m Figure 6.22: Change of Flow Rate with the Length after modified by Rashidpur- Ashugonj Loop Line 99 ,/' ~ @, Nel:Kona: N117: 10:30.00 psig DJamal: 4.00 m~c KTL1: 707.92Jnsm3/d ritBSdGF' 'men I DJDTDSl: 76.00 mmscfJi BBeter: 991.09 rnsm3/d Jamunaff: 4S.UO mmsc FenPP: 20.00 mmsctJd ,:':...Ehj)~ 4530.70 msm3fd Elenga.Nolka line ~- Dhanua Ndka J82 JB1 HGF1: 7645.55 msm3fd . ,OM,eFF ;;:} KaliGF: BBari: 56.00 rr1rnscf/d DJDevpur: 6.00 Dlongi: ZiaFF: 45.00 mmscfJd BakhraGF: ~ 1'"," Ba'h,e' K,Bep", B;j,e Lok,hem Fen;~. J42 MSh"e; Bereb Fo,lderagC'y: .~ 880.33 psig N115: 2.00 mmscf/d 70.00 mmscfJd MegPP Figure:6.23 ShiddP5: 40.00 mmscffd SanguGF: 4530.70 msm3Jd Figure 6.23: Demand-Supply Scenario of Gas Transmission Lines modified by Using R-A Loop Line and mentioning Known Pressure at Ashugonj , 100 .~ ,.~ ------_ .. __ ._---- 1150 1100 __ N-S line .Ql 1050 (/) 0... -D--B-Cline 1000 ~ ,1,-,,-.. I B-D line 950 (/)iil R__ A-E line ~ ------~1'-~----'-~ 0... 900 - ,-- - . ------*- R-A loop line 850 800 o 50 100 150 200 Length, Km Figure 6.24: The Variations of Pressure with the Length after modified by Rashidpur- Ashugonj Loop Line for Pressure Matching 6.7 Extension of Network up to Bheramara The existing network will be expanded up to Bheramara in near future according to the plan of Asian Development Bank. In Figure 6.25, 85 km 24" OD Nolka-Ishwardi- Bheramara gas transmission pipeline is connected to the network to facilitate gas supply to the planned industries in the Ishwardi EPZ and the power plants at Ishwardi and Bheramara. Assuming the total loads in the Western region are 140 MMSCFD, the network is simulated, The simulated results are tabulated in Appendix 8. Figure 6.26 shows the pressure drops along the major gas transmission lines. The inlet pressure at North-South pipeline is 1090 psig. The pressure drops in the major transmission lines are comparable to pressure drop which is obtained from the rule of thumb. Therefore, there is no unusual pressure drop anywhere in the network after extension of network up to Bheramara. Figure 6.27 shows the flow rate of major gas transmission lines. After extension, the capacity of North-South line with Rashidpur-Ashugonj loop line will be 840 MMSCFD. The capacity of Ashugonj-Elenga line is 387 MMSCFD. Therefore, there is no unreal situation in the network. The R-A loop line will increase the gas flow between Rashidpur and Ashugonj points significantly. 101 ~Ae,pu,~~ 14 mmscf/d ~ LX NetKona N61 N111 Sylhel: 76 mmscf Id N4 ~ FenPP olka Elenga Rashidp 160 mmscf/d shurdi RashidGF HGF1 270 mmscl/d DTangile BBari 46 mmscf/d 20 mmscf/d ShahjiPP DJDevpur ~ B~ria ~- ~ BheraPP APS 40 mmscf/d 175 mmscf/d N113 Tarabo Tarabo# DGulshan B-D line @ S.C line 'ewnbag Laksham Feni J42 MShar~arab DDemra agC~y Q: 258 mmscf/d N76 P: 1062 Psig N115 HariPP: 80 mmsf/d MegPP : 77 mmsf/d SanguGF ShlddPS: 52 mmscf/d Figure 6.25: Demand-Supply Scenario of High Pressure Gas Transmission Lines by extension of Network up to Bheramara ,0~ 102 ------~------1095 1090 .~ 1085 -+--N-S line c.. 1080 --B-C line -_ .. _._------:J~ 1075 ,~- B-D line ~ 1070 A-E line £ 1065 ------1------._- __ R-A loop line 1060 1055 o 50 100 150 200 Length, Km Figure 6.26: Variation of Pressure Drop along Major Transmission Lines by Extension of Network up to Bheramara 600 ( -". 500 - -_._--_.----~_._------_. ------j;--_. ------ ~ ~ _._- -_. __ ._------u 400 ------+-- N-S line (/) , :::s , _. --B-C line :::s 300 - ._-- . ------_._------_._------I 'iii" ~ B-D line •... I -- . _._. ------.- ~ 200 ------G:0 A-E line "'" . 100 _ . - . ------_ .._----- 1- 0 , o 50 100 150 200 Length,Km Figure 6.27: Change of Flow Rate along the Major Transmission Lines by Extension of Network up to Bheramara 103 \...) 6.6 Extension of Network up to Khulna without Modification In near future the demand of gas in the Western region will increase. According to the. report of Asian Development Bank, the network should be extended up to Khulna within 2010. Then the demand would reach 1900 MMSCFD (average). But GTCL forecasted that the average gas demand would be 1700 MMSCFD to 1900 MMSCFD. Therefore, this case has been studied using the demand as 1734 MMSCFD. In Figure 6.28, extending of transmission lines up to Khulna modifies the network. Assuming total loads in the Western region are 320 MMSCFD, the scenario is simulated. The major loads are assumed as follows: Bheramara 70MMSCFD Khulna 100MMSCFD EPZ IOMMSCFD Baghabaria 100MMSCFD Shirajgonj 40MMSCFD The simulated results are shown in Appendix 9. The large pressure drop (I78 psig) in Ashugonj-Elenga line (Figure 6.29) is the indication of inability of line to carry the expected flow. The pressure drop in Elenga- Khulna line is 88 psig, which is also greater than the recommended pressure drop (20 psig). The pressure at Khulna is 749 psig. Therefore, it is not possible for Ashugonj- Elenga line to carry the required flow. The flow capacity in major transmission lines by extension of network withou! any modification is shown in Figure 6.30. In Bakhrabad-bemra line, the flow rate is increased at Dewanbag point because 41.85 MMSCFD flow is added at this point from Demra and 53.17 MMSCFD flow is added at the same point from Sonargaon. The flow situation of other transmission lines has been discussed previously. Therefore, it is required to modify the network. The next cases are studied to overcome the existing pressure problem. 104 ./' ... ~~ ••pur~~ . JaBadGF DJamal ~ MmenPP a LX NetKona ~r;GF 120 mmscl/d J ail'ur JJI A ~Mymen Khadim K~ 40 mmscf/d N111 BBezar N60 Sylhet: 80 mmscf/d JamunaFF E,i., hp,:: FenPP ,t•..E line : 250 mmscl/d hurdi h'olka JB2 J81 Manifold ShahjiPP KatjGF: 40 mmscl/d HasGF: 300 mmscf/d APS 15 mmscf/d B-D line 8.C line oGaon Bakhrabadlt Ku8apur Bijra Laksham Feni J42 MSharai Sarab aujdar ~ CgCity DDemra Khulna F: 300 mmscf/d P: 982.9 Psig 100 mmscf/d N76 740.55 Psig MegPP N115 _ 160 mmscf/d ShiddPS SanguGF Figure 6.28: Demand-Supply Scenario of High Pressure Gas Transmission Lines by extension of Network up to Khulna without Modification 105 (iii;;' , F~ 1100 1050 -+- N-S line 0> 1000 ,-~.- 'w --B-C line c. 950 --'--- B-D line ~ :J 900 (/) A-E line (/) 850 ~ --R-A loop 0... 800 __ E-K line 750 700 o 100 200 300 400 Length, Km Figure 6.29: The Variation Pressure of Major Transmission Lines by extension of Network without any Modification 900 800 .------ I!' ------_. 1------. ----- 0 700 LL -+- B-C 0 600 - ._--~_ .._------_.------line1 (J) ---- B-D line :2: ._ .._- :2: 500 - A-E line Q) 400 - - -- R-A loop I -•...ro __ E-K line ::: 300 - t--.: - ~ .----- 0 -- --N-S line LL ------._- -- _. - ---- ;:v- - J 200 -,,-_.- '" ~ ..~- 100 _I T 0 o 100 200 300 Length, Km Figure 6.30: Change of Flow Rate along the Major Transmission Lines by extension of Network without any Modification 106 6.6.1 Extension of Network up to Khulna with Ashugonj-Dhanua Loop Line According to the study of Asian Development Bank, it is clear that the existing network will be extended up to Khulna within 2010. New power plant and fertilizer factory will be set up in the Western region. Then demand of gas in this region will increase. Before the extension to Khulna within the transmission lines, R-A loop line (69 km, 30" aD) and Ashugonj-Dhanua loop line (69 km, 30" aD) will be completed on priority basis. The network with Bheramara to Khulna transmission line is shown in Figure 6.3 J. Assuming the total load in the Western region as 320 MMSCFD, the scenario is simulated. The major loads are assumed as follows: Bheramara 70MMSCFD Khulna 100MMSCFD EPZ 10MMSCFD Baghabaria 100MMSCFD Shirajgonj 40MMSCFD The simulated results are tabulated in Appendix 10. Figure 6.32 shows the pressure drops along the major gas transmission lines. The pressure gradient in Ashgonj-Dhanua loop line is 0.0662 psig/km. The pressure gradient in other lines is very close to the recommended pressure gradient. The pressure at Khulna is 1039 psig. Therefore there is no shortage of pressure anywhere in the network after completing Ashgonj-Dhanua loop line. Figure 6.33 shows the simulated flow rates of major gas transmission lines. After completing Ashgonj-Dhanua loop line, the capacity of North-South line with Rashidpur- Ashugonj loop line will be 1116 MMSCFD. The capacity of Ashgonj-Dhanua line is 3689 MMSCFD. Then the capacity of Ashugonj-Elenga line with Ashgonj-Dhanua loop line will be 559 MMSCFD. Therefore, it is a possible option to construct the Ashgonj-Dhanua loop line for increasing the gas flow in the Western Region in future. 107 ~A._~~ OJ.mol ~1Put MmenPl' ri LX NelKOIl8 ~ - AMymen SGIlrj : 40 """ef/d N61 N1ll N80 5yihot eo mmsefld N.5 rme FenPl' ~ 20nmscf/d Resl"lkt3F 250 rnrnocf/d Illart/old SI10hjFP KatiGF: 40 mrmclld Tlos(lf 15mmscl/d B-Dline B.C iin,:, :oGaon BokIv.bodlI ~r 8Ijra Lakstlem Feni .142 _01 P: 1062.6 p,ig Ilor'" 014<1'" ctgClly P.1056.6 P1ig N7B F: 300 """ef/d N1l5 160.00 nmscf/d _:52nmscf/d ~ Figure 6.31: Demand-Supply Scenario of High Pressure Gas Transmission Lines by extension of Network up to Khulna with A-D Loop Line 108 :'\ , 1100 1090 -+- N-S line .gl 1080 -a-B-C line (/) --r ----~ ----- C- B-D line 1070, Ol... A-E line ::J ~~l- (/) 1060 __ R-A loop (/) ~ ...Ol a. 1050 __ E-K line 1040 --+- A-D loop 1030 0 100 200 300 400 Length,Km Figure 6.32: The Variation of Pressure along the Major Transmission Lines by Extension of Network up to lUmina with Ashugonj-Dhanua Loop Line. 1000 900 800 o -+-N-S line LL () 700 -a-B-C line (/) ~ 600 B-D line ~ 500 A-E line Ol .1 _ __ R-A loop ~ 400 ;;: __ E-K line o 300 LL -----:--..---d-"------+- A-D line 200 .. _~.:------100 o o 100 200 300 Length, Km Figure 6.33: Change of Flow Rate along the Major Transmission Lines by Extension of Network up to Khulna with Ashugonj-Dhanua Line. 109 r \ \ "\. 6.6.2 Modification of Nolka to Khulna Line by Using Loop Line from Rashidpur- Ashugonj Loop Line to Dhanua To reduce the stress on the Ashugonj Station, the network has been modified with a loop line from Rashidpur-Ashugonj loop line to Dhanua (69 KIn, 30" OD). Figure 6.34 shows the modification of Nolka to Khulna line by using loop line from Rashidpur- Ashugonj loop line to Dhanua. Assuming the total load in the Western region is 320 MMSCFD, the scenario is simulated. The major loads are assumed as follows: Bheramara 70 MMSCFD, Khulna 100 MMSCFD EPZ 10 MMSCFD, Baghabaria 100 MMSCFD Shirajgonj 40 MMSCFD The simulated results are tabulated in Appendix 11. Figure 6.35 shows the pressure drops along the major gas transmission lines. In North- South line, the pressure gradient is 0.112 psig/km. The pressure gradient in Rashidpur- . Ashugonj loop line, Bakhrabad-Demra line, Bakhrabad-Chittagong line, Ashugonj- Elenga line and loop line from Rashidpur-Ashugonj loop line to Dhanua are 0.124 psig/km, 0.274 psig/km, 0.082 psig/km, 0.0934 psig/km and 0.062 psig/km respectively. The pressure gradient in Bakhrabad-Demra line is larger due to the larger velocity of gas in this line compare to others. Figure 6.36 shows the flow capacity of major gas transmission lines. First jump of flow in North-South line occurs at Rashidpur manifold station due to 250 MMSCFD gas is added from Rashidpur gas field. Then it is divided into two parts; one part (741 MMSCFD) is passed through Rashidpur-Ashugonj loop line and other part (128 MMSCFD) is passed through N-S line. The loop line from Rashidpur-Ashugonj loop line to Dhanua can carry 188 MMSCFD for which sharp decrease of flow is observed in Rashidpur-Ashugonj loop line. Therefore, after completion of the proposed loop line, the capacity of North-South line with Rashidpur-Ashugonj loop line will be 1117 MMSCFD. Considering the above discussions, it is clear that it is possible to modify the network by using loop line from Rashidpur-Ashugonj loop line to Dhanua. 110 ~).. \ " ~ ~SI1etP'" ~ --o---@ DJIIIm!III .L..lelmeIlpur ~pp ./ LX NetKonll - ---- ,0 N111 BBelntr ".P:l059 Psig <\-t:: Ilr,e R-A loop line to Bengo Dhanu" loop line HQfl 270mrmcf/d '*'ntfcld Kl!tl"lata SI,,".PI' 36t1'll1'1SCfJd E ¥, 'jne D.De'IIJJUI' KallGF : 40 mmtelld Tltl!llsGF 300mmscf/d olio Sh •• 70 mmtef/d f ,. N113 B.D line SOGoon 8.( 1'(;'" rJl'$$Of8 F, J42 ••••••••• ...... , 'el4der QgCIy 300 mrnsc:f/d ~ MegPP : 105 mrnscIJd 1 ------_.------_._-_.-- Figure 6.35: The Pressure Drops of Major Transmission Lines of Nolka to Khulna Pipeline Using Loop Line from Rashidpur-Ashugonj Loop Line to Dhanua 1000 __ N-S line I 0 ou.. 800 (f) -- B-C line :2 600 :2 B-D line 400 A-E line -I~----:~. 200 ---.*-R-A loop line o o 50 100 150 200 Length, Km ------_.------.----- _._._-- Figure 6.36: Change of Flow Rate along the Major Transmission Lines of Nolka to Khulna Pipeline Using Loop Line from Rashidpur-Ashugonj Loop Line to Dhanua 112 ---- /" ( '. 6.8.3 Modification by Using Compressor Station at Monohordi The construction of loop line is time consuming and lengthy process. Therefore, the network can be modified alternatively. Using compressor station at Monohordi (1500 hp, 70% efficiency) instead of Ashugonj-Dhanua loop line the network can be modified as shown in Figure 6.37. The simulated results are shown in Appendix 12. The inlet pressure to the North.South pipeline is 1090 psig which is equal to the design pressure. But the pressure drop in the North-South line is high. The pressure drops in the other transmission lines are nearly equal to the recommended pressure drop. The variation of pressure along the transmission lines is shown in Figure 6.38. Ashugonj- Elenga line shows the effect of compressor at Monohordi. I 113 \ ~~_r~~0JemaI" ; 1=J'>..."'-LX NetKona NIl1 N111 _or N60 D.J)TDSl: 90.00 mmscf/d Jl """cf/d N.S line Ferl'!' Sl\ehjPp: 36 mm.cf/d KstlOF : 40 lTITl~f/d TlasGF F: JlO mnm:f/d 8-C line Bakh_ K1lIloIJU'BITe Laklll1am Feli J42 MSMrai B«ab ••.••••. OgCly P:llm.1 P.ig N76 F: JlO rnmad/d HerI'P : 95 mmsl/d W F: 160 nmad/d SltiP.; : 52 rnmad/d SanguClF Figure 6.37: Demand-supply Scenario of High Pressure Gas Transmission Lines modified Final Network by Using Compressor Station a Monohordi 114 . ~. 1100 -+-N-S line 1080 OJ __ B-C line "iii 1060 c. B-D line ~ 1040 ~ 1020 A-E line VJ ~ 1000 --*- R-A loop D.. 980 --E-K line 960 o 100 200 300 400 Length, Km ------_._"---~------_._----_._------ Figure 6.38: The Variation of Pressure along the Major Transmission Lines modified by Using Compressor Station at Monohordi 115 Chapter 7 DISCUSSIONS There are twenty-two gas fields in Bangladesh. At present, gas is lifted from twelve gas fields. The peak lifted gas in June 2000 was 1013 MMSCFD. After lifting natural gas from the fields, the gas Companies produce pipeline quality gas through process plants. Then, the treated gases are delivered to the transmission pipeline through fiscal meter. The Orifice meter is used as a fiscal meter and for monitoring accurately the flow recorder is connected with the orifice meter. Beyond this, the hourly calculations of flowing gas are recorded from the gas fields to the transmission line. To improve the supply/demand balance and to enhance the satisfaction of gas customers, Petrobangla has moved progressively from four separate systems (JFA, TFA, BFA and WFA) to an integrated transmission network. The reliability and security of gas supply in the national gas grid is largely dependent on the following pipelines: 1. 174 km, 24" OD North-South Gas Transmission Pipeline 2. 12" OD 38 km Ashuganj- Habiganj Gas Transmission Pipeline 3. 14" OD 58 km Titas-Narshindi-Demra Gas Transmission Pipeline 4. 16"/14" OD 82.81 km Titas-Narshindi-Joydevpur Gas Transmission Pipeline 5. 20" OD 48 km Bakhrabad-Demra Gas Transmission Pipeline 6. 20" OD 48 km offshore Sub Sea Sangu Gas Transmission Pipeline 7. 14" OD 15 km Jalalabad - Kailashtilla Gas Pipeline 8. 20" OD 18 km Beanibazar-Kailashtilla Pipeline 9. II" OD 37 km Salda- Bakhrabad Pipeline 10. 8" OD 28 km Meghna Gas Field- Bakhrabad Pipeline If the transmission network is carefully analyzed it appears that Ashuganj is the focal points of the National Gas Grid. Two key locations of Ashuganj are mainline Valve Station-3 of Titas-Narshindi-Demra transmission pipeline and Manifold station of GTCL. Gas from the Northern Gas Fields (Beanibazar, Jalalabad, Kailashtilla, .Rashidpur, Habiganj) are being transported through the North-South pipeline to Ashuganj Manifold Station of GTCL from where it is further transmitted to Titas 116 franchise area (TFA) and Bakhrabad franchise area (BFA) through Brahmaputra Basin pipe line and Ashuganj- Bakhrabad transmission pipe lines respectively. From Bakhrabad Gas Field, Bakhrabad-Chittagong Pipeline transports part of the required gas for Chittagong. The remaining gases for Chittagong is supplied from Salda, Meghna and Sangu gas fields. The mother trunk line i.e. North- South Pipeline has a design capacity of 330 MMSCFD. However considering the staggered nature of input into the pipeline and adjusting the terminal pressures at various in-take points and at Ashuganj it may be possible to transport 400 MMSCFD through the pipeline. Currently it is transporting approximately 353-380 MMSCFD, which merely cater to the downstream gas demand. During the past few years Bakhrabad gas field has been experiencing rapid pressure decline and increased water cuts in the wells. As a result, some wells have been shut off and some have been re-completed. In the year 1992 this field produced in its peak at an average 195 MMSCFD. In 1998, only five wells were producing from three sands at the rate of 50 MMSCFD. At present, the field is delivering gas at the rate of 35 MMSCFD at 600 psig. Currently Bakhrabad gas field is connected to the network system by reducing the pressure of Bakhrabad to Demra pipeline. If the line pressure is not reduced the Bakhrabad gas field could not be connected to the transmission system without compressor. When the proposed power plant will be started in peak production, the pressure of B-D line needs to be increased. Then Bakhrabad gas field will face a lot of pressure problem. If BGF is stopped production, it will not be possible to reach recoverable reserve and it will be a dead well. To overcome this problem, a compressor station should be set up at Bakhrabad gas field. The power of compressor must be greater than 700 hp at 70 % efficiency. The demand of gas was increasing day by day in fertilizer, power, industry and commercial sectors. If the proposed power plants start their production, the demand of gas will increase. To recover this demand, it is necessary to lift gas at higher rate. Therefore, 856 MMSCFD will be delivered from JFA. The maximum allowable operating pressure of the North- South p-ipeline is 1135 psig, its maximum inlet pressure 1090 psig and the normal pressure in A-shugonj is 850 psig. From Appendix 3, it is clear that N-S pipeline and Gas Fields experience unexpected pressure that is greater than its design pressure to reach the desired flow rate. From the simulated result, it is clear that after completing R-A loop line, the capacity of N-S pipeline with R-A loop line will be 117 increased and become 850 MMSCFD. Therefore, it is necessary to construct a loop line from Rashidpur to Ashugonj to deliver excess flow at design pressure on priority basis. If a new loop line from R-A loop line to Dhanua is constructed, the capacity ofN-S line with R-A loop line will be 790 MMSCFD. Even though the pressure drop in the major transmission lines will be low to meet the demand of Western Region. Therefore, R-A loop line to Dhanua loop line needs to be completed after completing R-A loop line. Now Ashugonj is the main points of the National Gas Grid. To reduction stress on Ashugonj station, it is required to construct loop line from R-A loop line to Dhanua loop line. There will be no problem in gas transmission system when the network will be extended up to Bheramara. Within 20 I0, the existing network will be expanded up to Khulna according to the report of Asian Development Bank. Then the gas demand would reach 1900 MMSCFD (average). Then the capacity of A-E line will have to be increased. If no loop line is constructed with A-E line, unexpected pressure drop will occur in A-E line (187 psig). Therefore, it is required to modify the network. To overcome the constraints of A-E line, three cases have been studied: i) A-D loop line ii) loop line from R-A loop line to Dhanua and iii) compressorstation at Monohordi. If A-D loop line is constructed, there is no shortage of pressure in the network. Therefore, it is possible to modify the network with A-D loop line. If a loop line from R-A loop line to Dhanua is constructed, large pressure gradient is observed in B-D line due to the larger velocity of gas in this line. To minimize pressure problem in Western region a compressor station may be set up at Monohordi. Therefore, according to the over all study, it will be better to construct A-D loop line or loop line from R-A loop line to Dhanua for reducing the stress on Ashugonj metering station. 118 ( Chapter 8 CONCLUSIONS AND RECOMMENDATIONS 8.1 Conclusions After analyzing the integrated gas transmission network of Bangladesh, the following conclusion can be drawn: I. Simulated results compare well with the actual data. Therefore, the network can be used to predict the future demand/supply scenario under existing and future supply and loads. 2. The results show that effective pipeline diameter of major transmission lines have decreased due to condensate accumulation. Hence pigging is necessary. 3. The maximum capacity of N-S pipeline is 400 MMMSCFD. Significant flow constraints and pressure drop arise in this line when the demand of gas is increased. 4. Rashidpur-Ashugonj loop line is essential to supply the growing gas demand. It will increase the capacity of the North-South pipeline by 456 MMSCFD. 5. Analysis shows that it is a better option to install a compressor station at Bakhrabad to transmit the low-pressure gas of the field through the high-pressure pipeline. 6. After completing R-A loop line, another loop line from R-A loop line to Dhanua or A-D loop line is required to minimize pressure problems in the transmission lines. 7. To extent of network up to Khulna, R-A loop line and loop line from R-A loop lines to Dhanua or A-D loop line must be completed on priority basis. 8. To minimize pressure problem in Western region a compressor station may be set up at Monohordi after completing R-A loop line instead of A-D loop line or loop line from R-A loop line to Dhanua. 9. To meet the future gas demand of the Western region, the results show that another loop line is necessary from Rashidpur-Ashugonj loop line to Dhanua. It will increase the supply of Ashugonj-Elenga pipeline by 175 MMSCFD. 119 8.2 Recommendations 1. To remove the constraint ofN-S pipeline, a loop line from Rashidpur to Ashugonj is to be constructed in priority basis. 2. The author strongly recommended for setting up a compressor station at Bakhrabad gas field. 3. For creating stability of gas supply in the Western region, a loop line is being set up from R-A loop line to Dhanua. 120 () . { « I \. , -} APPENDICES Appendix 1: Simulated Results of High Pressure Gas Transmission Lines of Bangladesh. From Node "To Node Up Stream Down Stream . . Lengtn 'Leg Flow ,Pressure Pressure Pressure . . (}adiant Psig Psig km MMSCFD Psiglkm JabadGF Ktilla 1092 1090 18 82.54 0.11111 Ktilla FenGanj 1090 1088.6 27 150.59 0.05185 FenGanj Rashidpur 1088.6 1084.9 67.5 150.59 0.05481 Rashidpur Habigonj 1084.9 1082.7 27.5 221.23 0.08 Habigonj KJ 1082.7 1079.3 35.5 354.2 0.096 KJ Ashugonj 1079.3 1077 18 354.2 0.13 Ashugonj Bakhrabad 1077 1075.7 57.1 229.4 0.02277 Bakhrabad KuBapur 1075.7 1075.2 15.7 120.1 0.03185 KuBapur Bijra 1075.2 1074 27.8 120.1 0.04317 Bijra Laksham 1074 1073.8 6 120.1 0.03333 Laksham Feni 1073.8 1072.1 40 120.1 0.0425 Feni J42 1072.1 1071.7 10 120.1 0.04 J42 Msgrai 1071.7 1070.6 25 120.1 0.044 Msgrai Barab 1070.6 1070.2 9 120.1 0.04444 Barab Faujdarhat 1070.2 1068.4 38 120.1 0.04737 Faujdarhat CtgCity 1068.4 1068 2.5 241.34 0.16 SanguGF Faujdarhat 1071.3 1068.4 49 119.8 0.05918 Bakhrabad Meghnaghat 1075.7 1071.8 30 175.86 0.13 Meghnaghat Sonar£!aon 1071.8 1068.1 15 175.85 0.25 Sonargaon Dewnbag 1068.1 1066.7 15 170.83 0.093 Dewnbag Demra 1066.7 1066 8 140.86 0.0875 Ashugonj Daulotkandi 1077 1075.9 5 134.58 0.22 Daulotkandi Monohordi 1075.9 1072.8 27 217.9 0.115 Monohordi Dhanua 1072.8 1071 37 59.08 0.04865 Dhanua Elenga 1071 1069.1 52 40.14 0.03654 Elenga Joydevpur 1069.1 1062.2 56 14.13 0.1232 Joydevpur Gulshan 1062.2 1061 25 11.45 0.048 Gulshan Demra 1061 1065.1 32 63.65 -0.1281 elenga nolka 1071.1 1068.5 39 15.24 0.06667 nolka Sganj 1068.5 1068.2 5 2 0.06 nolka Bbari 1068.5 1065.8 43 13.19 0.06279 Elenga JaGanj 1071.1 1068.6 43 10.75 0.05814 JaGanj JamunaFF 1068.6 1068.6 2 3.74 0 JaGanj Shbari 1068.6 1059.9 11 7.02 0.79091 shBabi Jamalpur 1059.9 1058.8 18 7.02 0.06111 Jamalpur Sherpur 1058.8 1052.4 16 3 0.4 121 I Dhanua GafGaon 1072 1071.7 19 18.94 0.01579 GafGaon Trishal 1071.7 1070.4 20.004 18.94 0.06499 Trisa1 mymen 1070.4 1065.5 16 18.94 0.30625 Mymen LX 1065.5 1060.6 8 16.94 0.6125 LX Mymenpp 1060.6 1058.2 5 14.88 0.48 Lx Neykona 1060.6 1053.8 32.5 2 0.20923 Monohordi kisGanj 1073.8 1071.5 36 2 0.06389 KA1 APS 1076.1 1015.1 1.5 100.99 40.6667 KA1 ZiaFF 1076.1 1075.9 2.4 0.005 0.08333 Dewnbag hariPP 1066.7 1066.7 1.58 29.86 0 FenGanj fenpp 1088.6 1088.6 0.5 0.005 0 RashidGF Rashidpur 1085.3 1084.9 1.9 70.62 0.21053 HGF1 Manifold 1085.3 1085.3 0.006 187.9 0 Manifold ShahjiPP 1085.3 952.2 2.5 36.61 53.24 Manifold Habigonj 1085.3 1082.7 1 132.24 2.6 Manifold Katihata 1085.3 1078.5 42 17.47 0.1619 Katihata Manif 1078.5 1076.1 11.5 17.47 0.2087 Manif Ashuganj 1076.1 1077 2 35.97 -0.45 N61 Ktilla 1090.01 1090 0.02 67.97 0.5 N111 N61 1088.9 1090.01 28 0.116 -0.0396 Nl11 N105 1088.9 1088.7 2.082 12.82 0.09606 N105 Sylhet 1088.7 1088.68 0.03 17.28 0.66667 HariGF N105 1089.2 1088.7 12 3.47 0.04167 SaldaGf Bakhrabad 1088.3 1075.7 35 15.12 0.36 MeghnaGF Bakhrabad 1117.7 1075.7 28 17.14 1.5 TitasGf Bbaria 1160.6 1092.4 1 303.2 68.2 Bbaria . TN1 1092.4 1090.8 1 152.4 1.6 Bbaria TN2 1092.4 1091.4 1 75.45 1 TN1 KA1 1090.8 1076.1 14.1 152.4 1.04255 KAI TN3 1076.1 1073.6 7 32.9 0.35714 TN3 Nars 1073.6 1066.8 30 32.9 0.22667 TN2 Daulot# 1091.4 1076 16 145.8 0.9625 Daulot# TN4 1076 1068 29 62.49 0.27586 TN4 Nars' 1068 1067.8 1 62.49 0.2 Nars Tarabo 1067.8 1066.5 20 2.87 0.065 Tarabo Demra 1066.5 1065.1 12 4.33 0.11667 Nars Tarabo# 1066.8 1066.1 40 21.91 0.0175 Tarabo# ShiddPP 1066.1 1066 5 20.45 0.02 ShiddPP ShiddPS 1066 1066 0.0003 14.62 0 ShiddPP N76 1066 1065.7 10 5.81 0.03 N76 Demra 1065.7 1065.1 10 5.81 0.06 Nras Ghorasal 1066.8 1060.1 8.4 233.7 0.79762 Ghorasal GhoraPP 1060.1 760.38 0.4 175.54 749.3 Ghorasal GhoraFF 1060.1 1051.8 8.4 55.31 0.9881 GhoraFF DGhoraFF 1051.8 1051.8 0.0003 43.2 0 GhoraFF PalashFF 1051.8 1051 0.8 12 1 122 Monohordi Nars 1073.8 1066.8 32 151.8 0.21875 Daulot# Daulotkandi 1076 1075.9 0.1 83.11 1 BelaboGF Nars 1084.9 1067.8 13 16.31 1.31538 Appendix 2: Simulated Results of High Pressure Gas Transmission Lines of Bangladesh modified by Known Pressure at Ashugonj. From Node To Node Up Stream Down Stream . .'Len~ 'Leg Flow ,Pressure" .' " 0 . Gadiant Pressure o. 0 Pressure 'Psig 'Psig " km MMSCFD Psigfkm JabadGF Ktilla 1108.6 1090 18 82.66 1.03333 Ktilla FenGanj 1090 1075.1 27 57.17 0.55185 FenGanj Rashidpur 1075.1 1035 67.5 57.16 0.59407 Rashidpur Habigonj 1035 1005 27.5 127.8 1.09091 Habigonj KJ 1005 948.44 35.5 242.98 1.59324 KJ Ashugonj 948.44 915.79 18 242.98 1.81389 Ashugonj Bakhrabad 915.79 891.17 57.1 188.88 0.43117 Bakhrabad KuBapur 891.17 876.67 15.7 122.98 0.92357 KuBapur Bijra 876.67 836.53 27.8 122.98 1.44388 Bijra Laksham 836.53 830.14 6 122.98 1.065 Laksham Feni 830.14 794.82 40 122.98 0.883 Feni J42 794.82 781.35 10 122.98 1.347 J42 Msgrai 781.35 756.07 25 122.98 1.0112 Msgrai Barab 756.07 743.5 9 122.98 1.39667 Barab Faujdarhat 743.5 701.42 38 122.98 1.10737 Faujdarhat CtgCity 701.42 700 2.5 242.79 0.568 SanguGF Faujdarhat 710.35 701.42 49 119.8 0.18224 Bakhrabad Meghnaghat 891.17 834.73 30 132.41 1.88133 Meghnaghat Sonargaon 834.73 790.54 15 132.41 2.946 Sonargaon Dewnbag 790.54 761.72 15 127.4 1.92 Dewnbag Demra 761.72 750.01 8 97.57 1.46375 Ashugonj Daulotkandi 915.79 912.36 5 151.02 0.686 Daulotkandi Monohordi 912.36 895 27 184.83 0.643 Monohordi Dhanua 895 880.0J 37 87.97 0.41 Dhanua Elenga 880.01 864.98 52 69.16 0.29 Elenga Joydevpur 864.98 793.74 56 4.03 1.27214 Joydevpur Gu1shan 793.74 730.48 25 32.34 2.5304 Gulshan Demra 730.48 750.01 32 19.42 -0.6103 elenga no1ka 864.98 862.53 39 15.13 0.06282 nolka Sganj 862.53 862.12 5 2 0.082 nolka Bbari 862.53 859.68 43 13.19 0.06628 Elenga JaGanj 864.98 861.85 43 10.7 0.07279 JaGanj JamunaFF 861.85 861.85 2 3.74 0 JaGanj Shbari 861.85 859.22 11 6.97 0.23909 123 shBabi Jamalpur 859.22 858.28 18 6.97 0.05222 Jamalpur Sherpur 858.28 855.61 16 3 0.16687 Dhanua GafGaon 885.01 860.72 19 18.81 1.27842 GafGaon Trishal 860.72 859.15 20.004 18.81 0.07848 Trisal mymen 859.15 858.09 16 18.81 0.06625 Mymen LX 858.09 856.07 8 16.82 0.2525 LX Mymenpp 856.07 855.71 5 14.88 0.072 Lx Neykona 856.07 853.93 32.5 2 0.06585 Monohordi kisGanj 895 865.72 36 2 0.81 KAI APS 915.2 873.11 1.5 100.99 28.06 KAI ZiaFF 915.2 915.2 2.4 0.005 0 Dewnbag hariPP 761.72 761.61 1.58 29.86 0.06962 FenGanj fenpp 1075.1 1075.1 0.5 0.005 0 RashidGF Rashidpur 1037.5 1035 1.9 70.62 1.31579 HGFI Manifold 1013.1 1013.1 0.006 187.9 0 Manifold ShahjiPP 1013.1 987.3 2.5 36.61 10.32 Manifold Habigonj 1013.1 1005 1 115.17 8.1 Manifold Katihata 1013.1 938.72 42 36.12 1.77095 Katihata Manif 938.72 915.2 11.5 36.12 2.04522 Manif Ashuganj 915.2 915.79 2 40.34 -0.295 N61 Ktilla 1090.1 1090 0.02 66.98 5 N111 N61 1088 1090.1 28 1.1 -0.075 Nll1 Nl05 1088 1088 2.082 13.8 0 NI05 Sylhet 1088 1088 0.03 17.28 0 HariGF NI05 1090.6 1088 12 3.47 0.21667 SaldaGf Bakhrabad 906.58 891.17 35 15.12 0.44029 MeghnaGF Bakhrabad 942.22 891.17 28 17.14 1.82321 TitasGf Bbaria 1075.1 1000.1 1 303.2 . 75 Bbaria TNI 1000.1 988.7 1 69.99 11.4 Bbaria TN2 1000.1 992.4 1 107.79 7.7 TNI KAI 988.7 915.2 14.1 69.99 5.21277 KAI TN3 915.2 895.86 7 45.69 2.76286 TN3 Nars 895.86 827.65 30 45.69 2.27367 TN2 Daulot# 992.4 912.41 16 107.79 4.99938 Daulot# TN4 912.41 832.49 29 73.96 2.75586 TN4 Nars 832.49 827.65 1 73.96 4.84 Nars Tarabo 827.65 787.86 20 34.53 1.9895 Tarabo Demra 787.86 750.01 12 54.61 3.15417 Nars Tarabo# 827.65 787.86 40 69.53 0.99475 Tarabo# ShiddPP 787.86 781.1 5 1.63 1.352 ShiddPP ShiddPS 781.1 781.1 0.0003 14.62 0 ShiddPP N76 781.1 763.52 10 1.15 1.758 N76 Demra 763.52 750.01 10 1.15 1.351 Nras Ghorasal 827.65 794.3 8.4 116.8 3.97024 Ghorasal GhoraPP 794.3 655.55 0.4 175.53 346.875 Ghorasal GhoraFF 794.3 793.82 8.4 55.1 0.05714 124 GhoraFF DGhoraFF 793.82 793.81 0.0003 43.2 33.3333 GhoraFF PalashFF 793.82 793.17 0.8 12 0.8125 Monohordi Nars 901.13 827.65 32 89.9 2.29625 Daulot# Daulotkandi 912.41 912.36 0.1 33.83 0.5 BelaboGF Nars 851.24 827.65 13 16.31 1.81462 Appendix 3: Simulated Results of High Pressure Transmission Lines Using Known Pressure at Bakhrabad Gas Field. From Node To Node Up Stream Down Stream Length Leg Flow Pressure Pressure, Pressure, Psig km MMSCFD Gadiant Psig Psildkm 0.47222 JabadGF Ktilla 1098.5 1090 18 83.52 0.16296 Ktilla FenGanj 1090 1085.6 27 150.58 FenGanj Rashidpur 1085.6 1055.7 67.5 150.58 0.44296 0.74182 Rashidpur Habigonj 1055.7 1035.3 27.5 221.23 Habigonj KJ 1035.3 980.3 35.5 361.14 1.5493 6.54722 KJ Ashugonj 1035.3 917.45 18 361.14 Ashugonj Bakhrabad 917.45 907.66 57.1 91.01 0.17145 0.31146 Bakhrabad KuBapur 907.66 902.77 15.7 121.5 0.31439 KuBapur Bijra 902.77 894.03 27.8 121.5 0.25333 Bijra Laksham 894.03 892.51 6 121.5 0.41925 Laksham Feni 892.51 875.74 40 121.5 0.696 Feni J42 875.74 868.78 10 121.5 0.6952 J42 Msgrai 868.78 851.4 25 121.5 0.91556 Msgrai Barab 851.4 843.16 9 121.5 0.91474 Barab Faujdarhat 843.16 808.4 38 121.5 Faujdarhat CtgCity 808.4 795.2 2.5 241.33 5.28 SanguGF Faujdarhat 860.15 808.4 49 119.8 1.05612 9.51533 Bakhrabad Meghnaghat 907.66 622.2 30 34.87 Meghnaghat Sonargaon 622.2 620.43 15 34.86 0.118 Sonargaon Dewnbag 620.43 618.77 15 29.86 0.11067 Dewnbag Demra 618.77 618.77 8 0 0 1.324 Ashugonj Daulotkandi 917.45 910.83 5 255.52 Daulotkandi Monohordi 910.83 895.2 27 262.93 0.57889 Monohordi Dhanua 895.2 875.97 37 97.38 0.51973 0.49019 Dhanua E1enga 875.97 850.48 52 78.48 1.32571 Elenga Joydevpur 850.48 776.24 56 40.5 0.52 Joydevpur Gulshan 776.24 763.24 25 0.348 -0.0644 Gulshan Demra 763.24 765.3 32 51.52 elenga nolka 870.48 860.3 39 15.21 0.26103 nolka Sganj 860.3 860 5 2 0.06 0.10349 nolka Bbari 860.3 855.85 43 13.19 -0.347 Elenga JaGanj 850.48 865.4 43 10.75 125 JaGanj JamunaFF 865.4 865.3 2 3.74 0.05 JaGanj Shbari 865.4 863.81 11 7.01 0.14455 shBabi Jamalpur 863.81 857.69 18 7.01 0.34 Jamalpur Sherpur 857.69 853.29 16 3 0.275 Dhanua GafGaon 875.97 865.25 19 18.9 0.56421 GafGaon Trisha1 865.25 859.58 20.004 18.9 0.28344 Trisal mymen 859.58 855.04 16 18.9 0.28375 Mymen LX 855.04 840.96 8 16.9 1.76 LX Mymenpp 840.96 840.06 5 14.88 0.18 Lx Neykona 840.96 837.17 32.5 2 0.11662 Monohordi kisGanj 895.2 868.62 36 2 0.73833 KA1 APS 870.44 504.82 1.5 100.99 243.747 KA1 ZiaFF 870.44 870.44 2.4 0 0 Dewnbag hariPP 618.77 617.95 1.58 29.86 0.51899 FenGanj fenpp 1085.6 617.95 0.5 0 935.3 RashidGF Rashidpur 1089.1 1055.7 1.9 70.62 17.5789 HGF1 Manifold 1073.3 1073.2 0.006 187.9 16.6667 Manifold ShahjiPP 1073.2 1047.8 2.5 36.61 10.16 Manifold Habigonj 1073.2 1035.3 1 139.89 37.9 Manifold Katihata 1073.2 1012.7 42 11.39 1.44048 Katihata Manif 1012.7 980.3 11.5 11.39 2.81739 Manif Ashuganj 980.3 917.45 2 11.39 31.425 N6l Ktilla 1091 1090 0.02 66.98 50 N111 N61 1088.9 1091 28 1.1 -0.075 NIl! N105 1088.1 1085.9 2.082 13.8 1.05668 N105 Sylhet 1085.9 1085.4 0.03 17.28 16.6667 HariGF N105 1089.4 1085.9 12 3.47 0.29167 SaldaGf Bakhrabad 922.78 907.66 35 15.12 0.432 MeghnaGF Bakhrabad 957.78 907.66 28 17.14 1.79 TitasGf Bbaria 1087.5 1005 1 303.2 82.5 Bbaria TN1 1005 996.4 1 173.32 8.6 Bbaria TN2 1005 999.9 1 124.88 5.1 TN1 KA1 996.4 870.44 14.1 173.32 8.93333 KA1 TN3 870.44 860.33 7 72.32 1.44429 TN3 Nars 860.33 820.31 30 72.32 1.334 TN2 Daulot# 999.9 910.86 16 124.88 5.565 Daulot# TN4 910.86 820.31 29 117.48 3.12241 TN4 Nars 820.31 817.29 1 117.48 3.02 Nars Tarabo 817.29 803.09 20 47.76 0.71 Tarabo Demra 803.09 765.3 12 4.32 3.14917 Nars Tarabo# 817.29 803.09 40 105.32 0.355 Tarabo# ShiddPP 803.09 802.7 5 148.76 0.078 ShiddPP ShiddPS 802.7 802.69 0.0003 14.62 33.3333 ShiddPP N76 802.7 801.1 10 134.15 0.16 N76 Demra 801.1 765.3 10 134.15 3.58 Nras Ghorasal 817.29 771.99 8.4 206.58 5.39286 126 Ghorasa1 GhoraPP 771.99 633.49 0.4 175.54 346.25 Ghorasal GhoraFF 771.99 723.53 8.4 55.2 5.76905 GhoraFF DGhoraFF 723.53 723.52 0.0003 43.2 33.3333 GhoraFF PalashFF 723.53 722.94 0.8 12 0.7375 Monohordi Nars 895.2 817.29 32 158.55 2.43469 BelaboGF Nars 841.2 817.29 13 16.31 1.83923 Appendix 4: Simulated Results of High Pressure Transmission Lines by setting up Compressor at Bakhrabad Gas Field. From Node: . To Node~- Up Stream Down Stream' ':Leilgth:- . Leg Flow. rPressure . '...... ", ',; , Pressure, Pressur~, Psig , . km." MMSCFD Gadiant . . , . Psig . - Psillikm JabadGF Ktilla 1098.5 1090.1 18 82.77 0.46667 Ktilla FenGanj 1090.1 1089.8 27 149.84 0.01111 FenGanj Rashidpur 1089.8 1060.9 67.5 149.83 0.42815 Rashidpur Habigonj 1060.9 1026.6 27.5 220.48 1.24727 Habigonj KJ 1026.6 950.6 35.5 318.65 2.14085 . KJ Ashugonj 950.6 873.32 18 371.79 4.29333 Ashugonj Bakhrabad 873.32 845.97 57.1 162.53 0.47898 Bakhrabad KuBapur 845.97 841.02 15.7 121.57 0.31529 KuBapur Bijra 841.02 832.18 27.8 121.57 0.31799 Bijra Laksham 832.18 830.64 6 121.57 0.25667 Laksham Feni 830.64 817.71 40 121.57 0.32325 Feni J42 817.71 810.56 10 121.57 0.715 J42 Msgrai 810.56 801.22 25 121.57 0.3736 Msgrai Barab 801.22 795.42 9 121.57 0.64444 Barab Faujdarhat 795.42 772.7 38 121.57 0.59789 Faujdarhat CtgCity 772.7 770.84 2.5 241.33 0.744 SanguGF Faujdarhat 798.38 772.7 49 119.8 0.52408 Bakhrabad Meghnaghat 845.97 829.52 30 107.65 0.54833 Meghnaghat Sonargaon 829.52 819.89 15 107.65 0.642 Sonargaon Dewnbag 819.89 808.1 15 102.64 0.786 Dewnbag Demra 808.1 805.45 8 72.76 0.33125 Ashugonj Daulotkandi 873.32 869.24 5 182.87 0.816 Daulotkandi Monohordi 869.24 855.58 27 203.66 0.50593 Monohordi Dhanua 855.58 850.61 37 86.33 0.13432 Dhanua Elenga 850.61 845.62 52 67.47 0.09596 Elenga Joydevpur 845.62 777.89 56 29.59 1.20946 Joydevpur Gulshan 777.89 778.64 25 8.76 -0.03 Gulshan Demra 778.64 805.45 32 43.32 -0.8378 elenga nolka 845.62 840.25 39 15.17 0.13769 nolka Sganj 840.25 839.1 5 2 0.23 nolka Bbari 840.25 829.8 43 13.19 0.24302 127 .( Elenga JaGanj 845.62 842.73 43 10.73 0.06721 JaGanj JamunaFF 842.73 842.7 2 3.74 0.015 JaGanj Shbari 842.73 842.05 11 6.99 0.06182 shBabi Jamalpur 842.05 836.95 18 6.99 0.28333 Jamalpur Sherpur 836.95 832.32 16 3 0.28938 Dhanua GafGaon 850.61 844.07 19 18.86 0.34421 GafGaon Trishal 844.07 837.07 20.004 18.86 0.34993 Trisal mymen 837.07 831.44 16 18.86 0.35188 Mymen LX 831.44 817.44 8 16.86 1.75 LX Mymenpp 817.44 817.41 5 14.88 0.006 Lx Neykona 817.44 813.11 32.5 2 0.13323 Monohordi kisGanj 855.58 841.04 36 2 0.40389 KAI APS 836.96 400 1.5 100.99 291.307 KAI ZiaFF 836.96 836.96 2.4 0 0 Dewnbag hariPP 808.1 808.1 1.58 0 0 FenGanj fenpp 1089.8 1089.8 0.5 0 0 RashidGF Rashidpur 1089.3 1060.9 1.9 70.62 14.9474 HGFI Manifold 1073.1 1073 . 0.006 187.9 16.6667 Manifold ShahjiPP 1073 1047.5 2.5 36.61 10.2 Manifold Habigonj 1073 1026.6 1 98.16 46.4 Manifold Katihata 1073 1016.6 42 53.13 1.34286 Katihata Manif 1016.6 915.8 11.5 53.13 8.76522 Manif Ashuganj 915.8 873.32 2 53.13 21.24 N61 Ktilla 1090.2 1090.1 0.02 66.98 5 Nlll N61 1090.1 1090.2 28 1.1 -0.0036 Nlll NI05 1090.1 1090 2.082 13.8 0.04803 NI05 Sy1het 1090 1089 0.03 17.28 33.3333 HariGF NI05 1090.6 1090 12 3.47 0.05 SaldaGf Bakhrabad 846.24 845.97 35 15.12 0.00771 MeghnaGF Bakhrabad 899.73 845.97 28 17.14 1.92 TitasGf Bbaria 1000.9 961.28 1 303.2 39.62 Bbaria TNI 961.28 944 1 145.6 17.28 Bbaria TN2 961.28 946.61 1 152.6 14.67 TNI KAI 944 836.96 14.1 145.6 7.59149 KAI TN3 836.96 832.6 7 44.6 0.62286 TN3 Nars 832.6 813.67 30 44.6 0.631 TN2 Daulot# 946.61 869.33 16 152.6 4.83 Daulot# TN4 869.33 816.09 29 131.81 1.83586 TN4 Nars 816.09 813.67 1 131.81 2.42 Nars Tarabo 813.67 810.17 20 24.52 0.175 Tarabo Demra 810.17 805.45 12 29.44 0.39333 Nars Tarabo# 813.67 810.17 40 47.7 0.0875 Tarabo# ShiddPP 810.17 809.75 5 42.78 0.084 ShiddPP ShiddPS 809.75 809.1 0.0003 14.62 2166.67 ShiddPP N76 809.75 807.6 10 28.17 0.215 N76 Demra 807.6 805.45 10 28.17 0.215 128 4.48452 Nras Ghorasal 813.67 776 8.4 225.84 399 Ghorasal GhoraPP 776 616.4 0.4 175.54 5.41071 Ghorasal GhoraFF 776 730.55 8.4 55.19 66.6667 GhoraFF DGhoraFF 730.55 730.53 0:0003 43.2 12 0.8375 GhoraFF PalashFF 730.55 729.88 0.8 1.30969 Monohordi Nars 855.58 813.67 32 110.35 16.31 2.84769 BelaboGF Nars 850.69 813.67 13 Appendix 5: Simulated Results of High Pressure Transmission Lines at Maximum Load. GLR Water Name Source/ Pressure Mass Rate Liquid Gas Rate Cut Sink Rate scfi'stb vol % Inlet F psig 1b/s STB/d" mmscf/d 161.88 0 JaBadGF Source 1350 81.79 0 BBazar Source 1312.7 17.68 35 200210 0 KTL234 Source 1311.9 47.39 424.55 85 200210 0 KTLl Source 1311.5 13.94 124.87 25 0 HariGF Source 1311.5 3.1 6 120 0 BibvaGF Source 1324.5 63.09 0 RashidGF Source 1312.9 80.84 160 0 HGFI Source 1214.3 136.42 270 0 TitasGF Source 918.75 155.24 300 0 KatiGF Source 981.67 47.69 90 0 Salda Source 837.5 15.52 30 0 MegnaGF Source 850.6 10.35 20 0.005 0 BakhraGF Source 772.17 0.00259 0 BelaboGF Source 725.75 10.35 20 0 SanguGF Source 5538.6 84.12 160 311.99 19815000 0 CtgCitv Sink 769.13 162.41 15.74 14030000 0 MegPP Sink 667.45 46.35 6.41 90 14030000 0 N115 Sink 668.38 1.03 0.143 2 14030000 0 HariPP Sink 668.92 36.05 4.99 70 47876000 0 ShiddPS Sink 678.19 20.61 0.835 40 27572000 0 DDemra Sink 668.92 46.36 3.26 90 27572000 0 DGulshan Sink 662.65 42.24 2.97 82 15608000 0 DJDevour Sink 662.3 3.09 0.384 6 13984000 0 BBari Sink 687.82 28.84 4 56 13984000 0 SGani Sink 687.84 20.6 2.86 40 13984000 0 JamunaFF Sink 687.76 23.18 3.22 45 36723000 0 GhoraPP Sink 524.92 96.33 5.09 187 36723000 0 DGhoraFF Sink 660.2 20.61 1.09 40 36723000 0 PalashFF Sink 660.2 10.82 0.572 21 13984000 0 MmenPP Sink 687.84 10.3 1.43 20 225950 0 DJDTDSL Sink 1296.8 42.12 336.36 76 2452300 0 FenPP Sink 1311.4 10.28 8.16 20 129 35 0 ShahiiPP Sink 1200 17.68 175 10130000 0 APS Sink 665.05 89.61 1.73 45 10130000 0 ZiaFF Sink 761.56 23.04 0.444 236.97 2452300 0 KTilla Manifold 1311.9 121.78 96.63 2452300 0 FenGanj Manifold 1290.8 121.78 96.63 236.97 7409200 0 Rashidp Manifold 1235.7 255.44 67.08 496.99 9638900 0 Habigani Manifold 1158.2 310.64 62.9 606.25 696.24 11621000 0 KJ Manifold 965.28 358.33 59.91 11621000 0 Ashugani Manifold 775.21 358.33 59.91 .696.24 374.49 14030000 0 Bakhra# Manifold 772.17 192.88 26.69 345.18 13984000 0 DauKandi Manifold 773.92 177.78 24.68 209.8 13984000 0 Dhanua Manifold 735.93 108.06 15 185.82 13984000 0 Elenga Manifold 687.84 95.7 13.29 96 13984000 0 Nolka Manifold 686.84 49.44 6.86 47.42 15608000 0 JDevpur Manifold 662.3 24.42 3.04 130.5 14030000 0 Dewnbag Manifold 690.54 67.21 9.3 132.5 14030000 0 SoGaon Manifold 730.38 68.24 9.44 222.5 14030000 0 MegnaPP Manifold 751.46 114.6 15.86 311.99 19815000 0 Faujdar Manifold 655.83 162.41 15.74 76 225950 0 Kuchai Manifold 1310.3 42.12 336.36 Appendix 6: Simulated results of high-pressure transmission lines modified network using R-A loop line. ~Length1 -Leg. Flow 1 "-Piessure1-1; .Down'Stream' p'" -', - ,';" ,'~ .::.t, To Node'": Up Streilin : ~; .• J;" "!' ••• ~ l' From Node: ~ - .,.~..~.".1'l "'n"" .;.. ...•..•-. ..' ~••.._,. ,",,",-.:.~t "~'. ~'"T'" '-,:" Pressure' • 'Pressure':: .- .. ' Gadiant .., . . MMSCFD Psiglkm . • Psig '.' ,. Psig km 18 210.85 0.47778 JabadGF Ktilla 1100 1091.4 289.18 0.044 Ktilla FenGanj 1091.4 1090.2 27 268.51 0.055 FenGanj Rashidpur 1090.2 1086.5 67.5 56.73 0.058 Rashidpur Habigonj 1086.5 1084.9 27.5 267.9 0.135 Habigonj KJ 1084.9 1080.1 35.5 18 267.9 0.02 KJ Ashugonj 1080.1 1076.5 440.4 0.03503 Ashugonj Bakhrabad 1076.5 1074.5 57.1 158.11 0.03822 Bakhrabad KuBapur 1074.5 1073.9 15.7 158.11 0.06115 KuBapur Bijra 1073.9 1072.2 27.8 158.11 0.1 Bijra Laksham 1072.2 1071.6 6 158.11 0.0625 Laksham Feni 1071.6 1069.1 40 10 158.11 0.09 Feni J42 1069.1 1068.2 25 158.11 0.06 J42 Msgrai 1068.2 1066.7 158.11 0.05556 Msgrai Barab 1066.7 1066.2 9 38 158.11 0.05789 Barab Faujdarhat 1066.2 1064 312.01 0.12 Faujdarhat CtgCity 1064 1063.7 2.5 160 0.01429 SanguGF Faujdarhat 1064.7 1064 49 130 Bakhrabad Meghnaghat 1074.5 1066.6 30 332.29 0.26 Meghnaghat Sonargaon 1066.6 1064.2 15 239.43 0.16 Sonargaon Dewnbag 1064.2 1061.7 15 237.36 0.17 Dewnbag Demra 1061.7 1061.1 8 165.14 0.075 Ashugonj Daulotkandi 1076.5 1075.8 5 306.38 0.14 Daulotkandi Monohordi 1075.8 1071.4 27 364.32 0.163 Monohordi Dhanua 1071.4 1068.2 37 191.14 0.086 Dhanua Elenga 1068.2 1064.6 52 166.39 0.069 Elenga Joydevpur 1064.6 1057.3 56 1.39 0.13036 Joydevpur Gulshan 1057.3 1059.5 25 0.796 -0.088 Gulshan Deinra 1059.5 1061.4 32 85.38 -0.0594 elenga nolka 1064.6 1062.3 39 99 0.05897 nolka Sganj 1062.3 1061.8 5 40 0.1 0.06047 nolka Bbari 1062.3 1059.7 43 56 Elenga JaGanj 1064.6 1052.1 43 53.62 0.2907 JaGanj JamunaFF 1052.1 1051.8 2 45 0.15 JaGanj Shbari 1052.1 1046 II 7.22 0.55455 shBabi Jamalpur 1046 1041.9 18 7.22 0.22778 Jamalpur Sherpur 1041.9 1037 16 3 0.30625 Dhanua GafGaon 1070.2 1066.8 19 24.75 0.17895 GafGaon Trishal 1066.8 1060.8 20.004 24.75 0.29994 0.3 Trisal mymen 1060.8 1056 16 24.75 Mymen LX 1056 1053.6 8 22.69 0.3 0 LX Mymenpp 1053.6 1053.6 5 20 0.11385 Lx Neykona 1053.6 1049.9 32.5 2 Monohordi kisGanj 1071.4 1070.1 36 2 0.036 KAI APS 1080.7 1057.3 1.5 175 15.6 3.04167 KAI ZiaFF 1080.7 1073.4 2.4 45 Dewnbag hariPP 1061.7 1060.7 1.58 90 0.633 FenGanj fenpp 1089.9 1063.8 0.5 20 52.2 RashidGF Rashidpur 1084.8 1086.5 1.9 160 0.15789 HGFI Manifold 1085.2 1085.2 0.006 270 0 Manifold ShahjiPP 1085.2 1006.4 2.5 35 31.52 Manifold Habigonj 1085.2 1084.9 I 211.17 0.3 Manifold Katihata 1085.2 1077.6 42 22.12 0.181 Katihata Manif 1077.6 1075.3 11.5 22.12 0.48696 Manif Ashuganj 1075.3 1076.5 2 100.86 -0.6 N61 Ktilla 1091.4 1091.4 0.02 43.33 0 NIII N61 1084.3 1091.4 28 41.67 -0.2536 NIII Kuchai 1084.3 1083 2.082 66.67 0.6244 Kuchai Sylhet 1083 975.5 0.03 76 3583.33 HariGF Kuchai 1085 1083 12 6 0.16667 SaldaGf Bakhrabad 1078.4 1074.5 35 30 0.11143 MeghnaGF Bakhrabad 1078.12 1074.5 28 20 0.12929 TitasGf Bbaria 1139 1088.2 I 300 50.8 Bbaria TNI 1088.2 1087 I 149.26 1.2 13]. 0.8 Bbaria TN2 1088.2 1087.4 I 147.67 0.44681 TNI KAI 1087 1080.7 14.1 149.26 1.15714 KAI TN3 1080.7 1072.6 7 45.81 0.25667 TN3 Nars 1072.6 1064.9 30 45.81 0.7625 TN2 Daulot# 1087.4 1075.8 16 147.67 0.34483 Daulot# TN4 1075.8 1065.2 29 89.73 0.3 TN4 Nars 1065.2 1064.9 I 89.73 0.09 Nars Tarabo 1064.9 1063.1 20 7.66 0.16667 Tarabo Demra 1063.1 1061.1 12 6.93 46.55 0.0375 Nars Tarabo# 1064.9 1063.4 40 0.2 Tarabo# ShiddPP 1063.1 1062.1 5 47.28 40 0 ShiddPP ShiddPS 1062.8 1062.8 0.0003 6.14 0.08 ShiddPP N76 1062.8 1062 10 6.14 0.09 N76 Demra 1062 1061.1 10 264.2 0.7381 Nras Ghorasal 1064.9 1058.7 8.4 187 547.8 Ghorasal GhoraPP 1058.7 839.58 004 62.74 0.22619 Ghorasal GhoraFF 1058.7 1056.8 8.4 0 GhoraFF DghoraFF 1056.8 1056.8 0.0003 40 21 0.25 GhoraFF PalashFF 1056.8 1056.6 0.8 0.203125 Monohordi Nars 1071.4 1064.9 32 165.95 57.94 0 Daulot# Daulotkandi 1075.8 1075.8 0.1 13 20 2.0692308 BelaboGF Nars 1091.8 1064.9 491.79 0.07 Rashidpur NI08 1086.5 1085.8 10 491.79 0.077 NI08 NI09 1085.8 1083.5 30 581.79 0.189 NI09 Ashugonj 1083.5 1076.5 37 120 0.36 BibyanaGF Rashidpur 1097.3 1086.5 30 90 10.3 KatiGF NI09 1090.8 1080.5 I Appendix 7: Simulated Results of High Pressure Transmission Lines modified Network Using R-A Loop Line by using Known Pressure at Ashugonj. Pressure From Node To Node Up Stream Down Stream Length Leg Flow Pressure Pressure Gadiant Psig Psig km MMSCFD Psiglkm 1.41667 JabadGF Ktilla 1115.5 1090 18 120 0.12963 Ktilla FenGanj 1090 1086.5 27 493.4 0.244 FenGanj Rashidpur 1086.5 1070 67.5 473.52 0.51 Rashidpur Habigonj 1070 1055.9 27.5 226.12 0.992 Habigonj KJ 1055.9 1020.7 35.5 377.35 377.35 1.68 KJ Ashugonj 1020.7 990.4 18 0.28704 Ashugonj Bakhrabad 990.4 974.01 57.1 416.64 0.30573 Bakhrabad KuBapur 974.01 969.21 15.7 255.99 0.45144 KuBapur Bijra 969.21 956.66 27.8 255.99 255.99 0.69167 Bijra Laksham 956.66 952.51 6 132 40 255.99 0.48925 Laksham Feni 952.51 932.94 10 255.99 0.733 Feni J42 932.94 925.61 25 255.99 0.4728 J42 Msgrai 925.61 913.79 9 255.99 0.71444 Msgrai Barab 913.79 907.36 38 255.99 0.46342 Barab Faujdarhat 907.36 889.75 2.5 415.99 0.968 Faujdarhat CtgCity 889.75 887.33 49 160 0.11224 SanguGF Faujdarhat 895.25 889.75 30 210.63 2.299 Bakhrabad Meghnaghat 974.01 905.04 15 120.84 1.67 Meghnaghat Sonargaon 905.04 880.04 15 118.84 1.668 Sonargaon Dewnbag 880.04 855.02 8 49 0.626 Dewnbag Demra 855.02 850.01 5 331.72 0.514 Ashugonj Daulotkandi 990.4 987.83 27 393.03 0.662 Daulotkandi Monohordi 987.83 969.96 37 216.98 0.244 Monohordi Dhanua 969.96 960.93 52 193.03 0.27 Dhanua Elenga 960.93 946.91 56 33.36 0.87554 Elenga Joydevpur 946.91 897.88 25 50.47 0.3516 Joydevpur Gulshan 897.88 889.09 32 31.33 -0.06 Gulshan Demra 848.09 850.01 39 95.8 0.05154 elenga nolka 946.91 944.9 944.6 5 40 0.06 nolka Sganj 944.9 941.9 43 56 0.06977 nolka Bbari 944.9 43 51.89 0.0707 Elenga JaGanj 946.91 943.87 2 45 0.055 JaGanj JamunaFF 943.87 943.76 11 6.99 0.09818 JaGanj Shbari 943.87 942.79 18 6.99 0.04389 shBabi Jamalpur 942.79 942 16 3 0.055 Jamalpur Sherpur 942 941.12 19 23.95 0.09368 Dhanua GafGaon 966.93 965.15 20.004 23.95 0.06499 GafGaon Trishal 965.15 963.85 962.43 16 23.95 0.08875 Trisal mymen 963.85 8 21.95 0.06625 Mymen LX 962.43 961.9 959.84 5 20 0.212 LX Mymenpp 960.9 32.5 2 0.07508 Lx Neykona 960.9 958.46 36 2 0.09389 Monohordi kisGanj 979.96 976.58 1.5 175 51.8267 KAI APS 995 917.26 2.4 45 3.33333 KAI ZiaFF 995 987 1.58 90 6.31646 Dewnbag hariPP 860.02 850.04 0.5 20 6.4 FenGanj fenpp 1086.5 1083.3 1.9 160 10.79 RashidGF Rashidpur 1090.5 1070 0.006 270 0 HGFI Manifold 1108.2 1108.2 2.5 35 6.28 Manifold ShahjiPP 1108.2 1092.5 1 151.23 55.3 Manifold Habigonj 1108.2 1052.9 42 83.77 0.97143 Manifold Katihata 1108.2 1024.2 11.5 83.77 5.05217 Katihata Manif 1024.2 994.8 2 93.39 2.2 Manif Ashuganj 994.8 990.4 0.02 40.01 0 N61 Ktilla 1090 1090 28 44.99 -0.0214 Nlll N61 1089.4 1090 133 0.72046 NIII Kuchai 1089.4 1087.9 2.082 69.99 5384.67 Kuchai Sylhet 1087.9 926.36 0.03 76 0.125 HariGF Kuchai 1089.4 1087.9 12 6 1.48257 SaldaGf Bakhrabad 1025.9 974.01 35 30 2.23179 MeghnaGF Bakhrabad 1036.5 974.01 28 20 52.6 TitasGf Bbaria 1103.1 1050.5 I 300 3.7 Bbaria TNI 1050.5 1046.8 I 116.95 4 Bbaria TN2 1050.5 1046.5 I 180.05 3.65248 TNI KAI 1046.5 995 14.1 116.95 1.76429 KAI TN3 995 982.65 7 74.34 74.34 1.77433 TN3 Nars 982.65 929.42 30 3.96438 TN2 Daulot# 1046.5 983.07 16 180.05 1.81414 Daulot# TN4 983.07 930.46 29 118.72 1.04 TN4 Nars 930.46 929.42 I 118.72 1.469 Nars Tarabo 929.42 900.04 20 65.83 4.16917 Tarabo Demra 900.04 850.Dl 12 75.61 0.7345 Nars Tarabo# 929.42 900.04 40 125.28 0.642 Tarabo# ShiddPP 900.04 896.83 5 115.5 0 ShiddPP ShiddPS 896.83 896.83 0.0003 40 2.662 ShiddPP N76 896.83 870.21 10 75.5 2.02 N76 Demra 870.21 850.Dl 10 75.5 188.8 3.19405 Nras Ghorasal 929.42 902.59 8.4 257.25 Ghorasal GhoraPP 902.59 799.69 0.4 187 1.4369 Ghorasal GhoraFF 902.59 890.52 8.4 60.98 0 GhoraFF DGhoraFF 890.52 890.52 0.0003 40 0.1375 GhoraFF PalashFF 890.52 890.41 0.8 21 1.267 Monohordi Nars 969.96 929.42 32 169.08 -47.6 Daulot# Daulotkandi 983.07 987.83 0.1 61.33 13 20 2.3915385 BelaboGF Nars 960.51 929.42 0.80 Rashidpur NI08 1070 1061.6 10 527.41 0.69 NI08 NI09 1061.6 1040.8 30 527.41 1.3621622 NI09 Ashugonj 1040.8 990.4 37 617.42 1.3233333 BibyanaGF Rashidpur 1104.7 1065 30 120 5.7 KatiGF NI09 1046.5 1040.8 I 90 , ') 134 ,\ / \ V Appendix 8: Simulated Results of High Pressure Transmission Lines modified Network by Extension of Network up to Bheramara. Length Leg Flow Pressure From Node To Node Up Stream Down Stream Pressure Pressure Gadiant Psig Psig km MMSCFD Psiglkm. 18 120 1.38889 JabadGF Ktilla 1115 1090 27 284.54 0.041 Ktilla FenGanj 1090 1088.9 67.5 264.18 0.067 FenGanj Rashidpur 1088.9 1084.4 27.5 44.16 0.09091 Rashidpur Habigonj 1084.4 1081.9 35.5 270.21 0.127 Habigonj KJ 1081.9 1077.4 18 270.21 0.16 KJ Ashugonj 1077.4 1074.6 57.1 406.68 0.03152 Ashugonj Bakhrabad 1074.6 1072.8 15.7 134.7 0.02548 Bakhrabad KuBapur 1072.8 1072.4 27.8 134.7 0.02158 KuBapur Bijra 1072.4 1071.8 6 134.7 0.03333 Bijra Laksham 1071.8 1071.6 40 134.7 0.045 Laksham Feni 1071.6 1069.8 10 134.7 0.08 Feni J42 1069.8 1069 25 134.7 0.06 J42 Msgrai 1069 1067.5 9 134.7 0.02222 Msgrai Barab 1067.5 1067.3 38 134.7 0.11053 Barab Faujdarhat 1067.3 1063.1 2.5 258 0.28 Faujdarhat CtgCity 1063.1 1062.4 49 128 0.05918 SanguGF Faujdarhat 1066 1063.1 30 322.01 0.26 Bakhrabad Meghnaghat 1072.8 1064.9 15 242.83 0.15 Meghnaghat Sonargaon 1064.9 1062.6 15 240.77 0.27 Sonargaon Dewnbag 1062.6 1058.5 8 158.52 0.0875 Dewnbag Demra 1058.5 1057.8 5 329.6 0.06 Ashugonj Daulotkandi 1074.6 1074.3 27 387.12 0.18 Daulotkandi Monohordi 1074.3 1069.4 37 224.31 0.1 Monohordi Dhanua 1069.4 1065.7 52 205.8 0.065 Dhanua Elenga 1065.7 1062.3 56 12.52 0.07321 Elenga Joydevpur 1062.3 1058.2 25 4.44 -0.056 Joydevpur Gulshan 1058.2 1059.6 32 60.99 0.05625 Gulshan Demra 1059.6 1057.8 39 139.82 0.04359 elenga nolka 1062.3 1060.6 5 30 0.12 nolka Sganj 1060.6 1060 43 46 0.06977 nolka Bbari 1060.6 1057.6 43 53.46 0.28605 Elenga JaGanj 1062.3 1050 2 45 0 JaGanj JamunaFF 1050 1050 11 7.2 0.53636 JaGanj Shbari 1050 1044.1 18 7.2 0.22222 shBabi Jamalpur 1044.1 1040.1 16 3 0.3125 Jamalpur Sherpur 1040.1 1035.1 19 18.5 0.058 Dhanua GafGaon 1065.7 1064.6 20.004 18.5 0.165 GafGaon Trishal 1064.6 1061.3 135 18.5 0.21875 Trisal mymen 1061.3 1057.8 16 16.45 0.225 Mymen LX 1057.8 1056 8 14 0 LX Mymenpp 1056 1056 5 2 0.12308 Lx Neykona 1056 1052 32.5 2 0.05 Monohordi kisGanj 1069.4 1067.6 36 175 10.7333 KAI APS 1072.6 1056.5 1.5 45 0.08333 KAI ZiaFF 1072.6 lO72.4 2.4 80 1.01266 Dewnbag hariPP 1060.5 1058.9 1.58 20 38.6 FenGanj fenpp 1087.9 1068.6 0.5 160 0.84211 RashidGF Rashidpur 1084 1082.4 1.9 270 16.67 HGFI Manifold 1084.6 1084.5 0.006 20 9.16 Manifold ShahjiPP 1083.5 1060.6 2.5 226.04 3.6 Manifold Habigonj 1083.5 1079.9 1 22.98 0.13333 Manifold Katihata 1083.5 1076.8 42 22.98 0.47826 Katihata Manif 1076.8 1074.4 11.5 98.78 -0.1 Manif Ashuganj 1074.4 1074.6 2 43.33 0 N61 Ktilla 1090 1090 0.02 41.67 -0.2429 Nlll N61 1083.2 1090 28 66.67 -2.7378 Nlll Kuchai 1083.2 1088.9 2.082 76 3747.67 Kuchai Sylhet 1088.9 976.47 0.03 6 -2.1333 HariGF Kuchai 1063.3 1088.9 12 30 -1.5371 SaldaGf Bakhrabad 1019 1072.8 35 20 -1.5714 MeghnaGF Bakhrabad 1028.8 1072.8 28 300 12.8 TitasGf Bbaria 1100 1087.2 1 150.57 1.2 Bbaria TNI 1087.2 1086 1 147.39 0.8 Bbaria TN2 1087.2 1086.4 1 150.57 0.95035 TNI KAI 1086 1072.6 14.1 46.22 0.12857 KAI TN3 1072.6 1071.7 7 46.22 0.25 TN3 Nars 1071.7 1064.2 30 147.39 0.75 TN2 Daulot# 1086.4 1074.4 16 89.88 0.34138 Daulot# TN4 1074.4 1064.5 29 89.88 0.3 TN4 Nars 1064.5 1064.2 1 8.09 0.04 Nars Tarabo 1064.2 1063.4 20 4.2 0.46667 Tarabo Demra 1063.4 1057.8 12 50.57 0.02 Nars Tarabo# 1064.2 1063.4 40 54.47 0.06 Tarabo# ShiddPP 1063.4 1063.1 5 52 0 ShiddPP ShiddPS 1063.1 1063.1 0.0003 1.08 0.09 ShiddPP N76 1063.1 1062.2 10 1.08 0.44 N76 Demra 1062.2 1057.8 10 254.62 0.69048 Nras Ghorasal 1064.2 1058.4 8.4 166 396.75 Ghorasal GhoraPP 1058.4 899.7 0.4 61.6 0.22619 Ghorasal GhoraFF 1058.4 1056.5 8.4 40 0 GhoraFF DGhoraFF 1056.5 1056.5 0.0003 20 0.125 GhoraFF PalashFF 1056.5 1056.4 0.8 158.71 0.225 Monohordi Nars 1069.4 1064.2 32 57.5 1 Daulot# Daulotkandi 1074.4 1074.3 0.1 t36 13 20 2.0230769 BelaboGF Nars 1090.5 1064.2 480.03 0.16 Rashidpur NI08 1084.4 1082.8 10 480.03 0.09 NI08 NI09 1082.8 1080.1 30 570.03 0.15 NI09 Ashugonj 1080.1 1074.6 37 100 0.223 BibyanaGF Rashidpur 1091.1 1084.4 30 90 7.6 KatiGF NI09 1085.6 1078 1 Appendix 9: Simulated Results of High Pressure Transmission Lines Extension of Network up to Khulna without any Modification Flow Rate, MMSCFD Source/ Delivery Name Source/ Deliverv. Pressure, Psig 300 Titas gas field Source 1114.3 270 Habigoni Gas field Source 1106.1 250 Rashidpur Gas Field Source 1091.7 120 Jalalabad Gas Field Source 1112.3 160 Sangu Gas Field Source 1004.7 15 Narshindi Gas Field Source 956.39 15 Meghna Gas Field Source 1038.5 15 Salda Gas field Source 1017.6 200 Kailashtilla(MSTE) gas Field Source 1090 60 Kailashtilla(Sillica) gas field Source 1089.9 30 Beanibazar Gas Field Source 1090.7 4 Haripur Gas Field Source 1088.9 300 Bibyana Gas Field Source 1181.3 40 Kati (Titas) Source 1097.9 0.005 Bakhrabad Gas Field Source 1004.9 140 APS Sink 947.75 180 GhoraPP Sink 863.38 95 HaripPP Sink 938.82 18 MvmenPP Sink 906.98 52 ShiddPP Sink 939.04 20 FenPP Sink 1088.9 36 ShahiPP Sink 1089.5 56 ZiaFF Sink 1002 40 GhoraFF Sink 932.84 20 PalashFF Sink 931.84 45 JamuanaFF Sink 828.01 Joydevpur Sink 932.81 9 80 Gulshan Sink 932.87 40 Shiraigoni Sink 824.87 100 Baghabari Sink 824.72 300 Ctgcity Sink 982.9 80 Sylhet Sink 926.24 110 Demra Sink 938.85 100 Khulna Sink 740.55 137 812.2 10 !EP-PP . Sink 70 BheraPP Sink 805.13 Appendix 10: Simulated Results of High Pressure Transmission Lines Extension of Network up to Khulna with A-D Loop Line. ~Leg Flow~ ::.:Ptessure;:' From Node .' To Node' , Up Stream DoWn Stream' Length . . -. . . , Gadiant Pressure Pressure <. Psig . Psig . kID .•.. MMSCFD Psiglkm 18 120 1.23889 JabadGF Ktilla 1112.3 1090 339.29 0.052 Ktilla FenGanj 1090 1088.6 27 319.45 0.07 FenGanj Rashidpur 1088.6 1083.9 67.5 140.42 0.11273 Rashidpur Habigonj 1083.9 1080.8 27.5 346.79 0.158 Habigonj KJ 1080.8 1075.2 35.5 18 346.79 0.239 KJ Ashugonj 1075.2 1070.9 57.1 481.5 0.03503 Ashugonj Bakhrabad 1070.9 1068.9 144.04 0.03822 Bakhrabad KuBapur 1068.9 1068.3 15.7 27.8 144.04 0.04317 KuBapur Bijra 1068.3 1067.1 144.04 0.03333 Bijra Laksham 1067.1 1066.9 6 144.04 0.045 Laksham Feni 1066.9 1065.1 40 10 144.04 0.07 Feni J42 1065.1 1064.4 25 144.04 0.088 J42 Msgrai 1064.4 1062.2 144.04 0.1 Msgrai Barab 1062.2 1061.3 9 144.04 0.12368 Barab Faujdarhat 1061.3 1056.6 38 300 0 Faujdarhat CtgCity 1056.6 1056.6 2.5 160 0.08163 SanguGF Faujdarhat 1060.6 1056.6 49 367.47 0.21 Bakhrabad Meghnaghat 1068.9 1062.6 30 260.39 0.17333 Meghnaghat Sonargaon 1062.6 1060 15 258.35 0.14 Sonargaon Dewnbag 1060 1057.9 15 161.47 0.0875 Dewnbag Demra 1057.9 1057.2 8 190.5 0.04 Ashugonj Daulotkandi 1070.9 1070.7 5 246.76 0.05556 Daulotkandi Monohordi 1070.7 1069.2 27 47.81 0.08378 Monohordi Dhanua 1069.2 1066.1 37 394.16 0.15577 Dhanua Elenga 1066.1 1058 52 14.88 0.09821 Elenga Joydevpur 1058 1052.5 56 0.466 0.084 Joydevpur Gulshan 1052.5 1050.4 25 81.15 -0.2125 Gulshan Demra 1050.4 1057.2 32 326.27 0.10256 elenga nolka 1058 1054 39 40 0.02 nolka Sganj 1054 1053.9 5 100 0.09767 nolka Bbari 1054 1049.8 43 53.02 0.28605 Elenga JaGanj 1058 1045.7 43 45 0 JaGanj JamunaFF 1045.7 1045.7 2 7.14 0.53636 JaGanj Shbari 1045.7 1039.8 11 138 •• 7.14 0.22222 shBabi Jamalpur 1039.8 1035.8 18 3 0.30625 Jamalpur Sherpur 1035.8 1030.9 16 22.43 0.04737 Dhanua GafGaon 1066.1 1065.2 19 22.43 0.06999 GafGaon Trishal 1065.2 1063.8 20.004 16 22.43 0.5125 Trisal mymen 1063.8 1055.6 20.39 0.275 Mymen LX 1055.6 1053.4 8 18 0 LX Mymenpp 1053.4 1053.4 5 2 0.11077 Lx Neykona 1053.4 1049.8 32.5 2 0.07778 Monohordi kisGanj 1069.2 1066.4 36 1.5 140 8.2 KAI APS 1070.6 1058.3 2.4 56 1.58333 KAI ZiaFF 1070.6 1066.8 1.58 95 5.18987 Dewnbag hariPP 1058.9 1050.7 20 39.4 FenGanj fenpp 1087.6 1067.9 0.5 1.9 250 1.10526 RashidGF Rashidpur 1084 1083.9 0.006 270 0 HGFI Manifold 1080 1080 2.5 36 33.28 Manifold ShahjiPP 1080 996.8 206.36 3.2 Manifold Habigonj 1080 1076.8 1 42 25.88 0.17857 Manifold Katihata 1080 1072.4 11.5 25.88 0.61739 Katihata Manif 1072.4 1069.7 70.12 -0.6 Manif Ashuganj 1069.7 1070.9 2 0.02 187.66 0 N61 Ktilla 1090 1090 28 12.38 -0.0714 N1l1 N61 1088 1090 2.082 72.33 12.44 Nlll Kuchai 1088 1062.1 0.03 80 3064 Kuchai Sylhet 1062.1 970.18 12 4 0.26667 HariGF Kuchai 1065.3 1062.1 35 15 0.34 SaldaGf Bakhrabad 1080.8 1068.9 15 1.12143 MeghnaGF Bakhrabad 1100.3 1068.9 28 1 300 53 TitasGf Bbaria 1135.5 1082.5 1 151.09 1.2 Bbaria TNI 1082.5 1081.3 146.86 1.2 Bbaria TN2 1082.5 1081.3 1 14.1 151.09 0.75887 TNI KAI 1081.3 1070.6 46.14 0.51429 KAI TN3 1070.6 1067 7 30 46.14 0.25 TN3 Nars 1067 1059.5 146.86 1.21875 TN2 Daulot# 1081.3 1061.8 16 90.6 0.06897 Daulot# TN4 1061.8 1059.8 29 90.6 0.3 TN4 Nars 1059.8 1059.5 1 12.01 0.065 Nars Tarabo 1059.5 1058.2 20 14.97 -88.1 Tarabo Demra 1057.2 12 73.05 0.0325 Nars Tarabo# 1059.5 1058.2 40 70.09 0.06 Tarabo# ShiddPP 1058.2 1057.9 5 52 333.333 ShiddPP ShiddPS 1057.9 1057.8 0.0003 16.93 0.04 ShiddPP N76 1057.9 1057.5 10 16.93 0.03 N76 Demra 1057.5 1057.2 10 8.4 259.52 0.71429 Nras Ghorasal 1059.5 1053.5 180 491.1 Ghorasal GhoraPP 1053.5 857.06 0.4 61.34 0.22619 Ghorasal GhoraFF 1053.5 1051.6 8.4 139 GhoraFF DGhoraFF 1051.6 1051.6 0.0003 40 0 GhoraFF PalashFF 1051.6 1051.5 0.8 20 0.125 Monohordi Nars 1069.2 1059.5 32 194.87 0.30313 Daulot# Daulotkandi 1069.7 1070.7 0.1 56.26 -10 15 1.1461538 BelaboGF Nars 1074.4 1059.5 13 0.07 Rashidpur NI08 1083.9 1083.2 10 729.22 O. t23 NI08 NI09 1083.2 1079.5 30 729.22 0.23 NI09 Ashugonj 1079.5 1071 37 769.2 2.95 BibyanaGF Rashidpur 1172.4 1083.9 30 300 KatiGF NI09 1076.4 1075.5 I 40 0.9 Ashugonj NI25 1070.9 1070.4 5 368.79 0.1 NI25 Dhanua 1070.4 1066.1 65 368.79 0.0661538 Appendix 11: Simulated Results of High Pressure Transmission Lines, Modification of Nolka to Khulna Line by Using Loop Line from R-A Loop Line to Dhanua From Node' "To Node .' 1,JpStr.earn' Down Stream" :Length; ~Legflow' " Pressure" , ' Pressure . Pressure ,~ " . . . ; Gaai;rnt . Psig Psig Ian MMSCFD Psiglkm JabadGF Ktilla 1112.3 1090 18 120 1.23889 Ktilla FenGanj 1090 1088.6 27 339.29 0.052 FenGanj Rashidpur 1088.6 1084.1 67.5 319.45 0.067 Rashidpur Habigonj 1084.1 1080.1 27.5 128.34 0.145 Habigonj KJ 1080.1 1072.5 35.5 335.28 0.214 0.12222 KJ Ashugonj 1072.5 1070.3 18 335.28 Ashugonj Bakhrabad 1070.3 1068.2 57.1 481.71 0.03678 Bakhrabad KuBapur 1068.2 1067.8 15.7 144.51 0.02548 KuBapur Bijra 1067.8 1066.1 27.8 144.51 0.06115 Bijra Laksham 1066.1 1065.8 6 144.51 0.05 Laksham Feni 1065.8 1063.6 40 144.51 0.055 Feni J42 1063.6 1062.7 10 144.51 0.09 J42 Msgrai 1062.7 1060.7 25 144.51 0.08 Msgrai Barab 1060.7 1059 9 144.51 0.18889 Barab Faujdarhat 1059 1055 38 144.51 0.10526 Faujdarhat CtgCity lOSS 1054 2.5 300 0.4 SanguGF Faujdarhat 1060.9 lOSS 49 160 0.12041 Bakhrabad Meghnaghat 1068.2 1059.1 30 367.23 0.303 Meghnaghat Sonargaon 1059.1 1054.4 IS 259.78 0.313 Sonargaon Dewnbag 1054.4 1051.2 IS 257.74 0.213 Dewnbag Demra 1051.2 1049.6 8 160.55 0.20 Ashugonj Daulotkandi 1070.3 1070.1 5 170.37 0.04 Daulotkandi Monohordi 1070.1 . 1068.8 27 227.39 0.04815 Monohordi Dhanua 1068.8 1066.4 37 25.3 0.06486 Dhanua Elenga 1066.4 1059 52 392.1 0.14231 140 56 15.06 0.10714 Elenga Joydevpur 1059 1053 25 0.649 0.008 Joydevpur Gulshan 1053 1052.8 32 81.22 0.1 Gulshan Demra 1052.8 1049.6 39 324.33 0.10513 elenga nolka 1059 1054.9 5 40 0.02 nolka Sganj 1054.9 1054.8 43 100 0.09767 nolka Bbari 1054.9 1050.7 43 52.71 0.28605 Elenga JaGanj 1059 1046.7 2 45 0 JaGanj JamunaFF 1046.7 1046.7 11 7.09 0.53636 JaGanj Shbari 1046.7 1040.8 18 7.09 0.22778 shBabi Jamalpur 1040.8 1036.7 16 3 0.3625 Jamalpur Sherpur 1036.7 1030.9 19 22.3 0.01579 Dhanua GafGaon 1066.4 1066.1 20.004 22.3 0.26495 GafGaon Trishal 1066.1 1060.8 16 22.3 0.26875 Trisal mymen 1060.8 1056.5 8 20.27 0.275 Mymen LX 1056.5 1054.3 5 18 0 LX Mymenpp 1054.3 1054.3 32.5 2 0.11077 Lx Neykona 1054.3 1050.7 36 2 0.05 Monohordi kisGanj 1068.8 1067 1.5 140 8.26667 KAI APS 1071 1058.6 2.4 56 1.58333 KAI ZiaFF 1071 1067.2 1.58 95 1.32911 Dewnbag hariPP 1053.2 1051.1 0.5 20 39.4 FenGanj fenpp 1087.6 1067.9 1.9 250 0.47368 RashidGF Rashidpur 1082 1081.1 0.006 270 0 HGFI Manifold 1080.1 1080.1 2.5 36 33.28 Manifold ShahjiPP 1080.1 996.9 1 206.93 2.2 Manifold Habigonj 1080.1 1077.9 42 25.31 0.17619 Manifold Katihata 1080.1 1072.7 11.5 25.31 0.22609 Katihata Manif 1072.7 1070.1 2 70.26 -0.1 Manif Ashuganj 1070.1 1070.3 0.02 187.66 0 N61 Ktilla 1090 1090 28 12.33 -0.0714 Nlll N61 1088 1090 2.082 72.33 12.2959 Nlll Kuchai 1088 1062.4 0.03 80 3074 Kuchai Sylhet 1062.4 970.18 12 4 0.24167 HariGF Kuchai 1065.3 1062.4 35 15 0.36857 SaldaGf Bakhrabad 1081.1 1068.2 28 15 1.16071 MeghnaGF Bakhrabad 1100.7 1068.2 1 300 51 TitasGf Bbaria 1133.9 1082.9 1 151.21 1.2 Bbaria TNI 1082.9 1081.7 1 146.74 0.8 Bbaria TN2 1082.9 1082.1 14.1 151.21 0.75887 TNI KAI 1081.7 1071 7 45.64 0.51429 KAI TN3 1071 1067.4 30 45.64 0.24667 TN3 Nars 1067.4 1060 16 146.74 0.75 TN2 Daulot# 1082.1 1070.1 29 89.72 0.34138 Daulot# TN4 1070.1 1060.2 1 89.72 0.2 TN4 Nars 1060.2 1060 20 12.21 0.07 Nars Tarabo 1060 1058.6 141 15.5 0.75 Tarabo Demra 1058.6 1049.6 12 74.96 0.035 Nars Tarabo# 1060 1058.6 40 70.97 0.06 Tarabo# ShiddPP 1058.6 1058.3 5 52 0 ShiddPP ShiddPS 1058.3 1058.3 0.0003 17.73 0.07 ShiddPP N76 1058.3 1057.6 10 17.73 0.8 N76 Demra 1057.6 1049.6 10 259.84 0.71429 Nras Ghorasal 1060 1054 8.4 180 491.15 Ghorasa1 GhoraPP 1054 857.54 0.4 61.44 0.22619 Ghorasal GhoraFF 1054 1052.1 8.4 40 0 GhoraFF DGhoraFF 1052.1 1052.1 0.0003 20 0.125 GhoraFF PalashFF 1052.1 1052 0.8 198 0.275 Monohordi Nars 1068.8 1060 32 57.02 0 Daulot# Daulotkandi 1070.1 1070.1 0.1 13 15 1.14615 BelaboGF Nars 1074.9 1060 741.3 0.23 Rashidpur N108 1084.1 1081.8 10 741.3 0.197 N108 N109 1081.8 1075.9 30 392.18 0.1405405 N109 Ashugonj 1075.9 1070.7 37 300 3.0433333 BibyanaGF Rashidpur 1172.4 1081.1 30 40 2.1 KatiGF N109 1078 1075.9 1 188.07 0.06232 N110 Dhanua 1070.7 1066.4 69 142 Appendix 12: Simulated Results of High Pressure Transmission Lines modified Network by using Compressor Station at Monohordi. Flow Rate, MMSCFD Source/ Delivery Name Source/ Delivery Pressure, Psig 300 Titas gas field Source 1106.3 270 Habigonj Gas field Source 1103.7 250 Rashidpur Gas Field Source 1090.8 120 Jalalabad Gas Field Source 1112.3 1010 160 Sangu Gas Field Source 952.47 15 Narshindi Gas Field Source 1043.6 15 Meghna Gas Field Source 1022.8 15 Sa1da Gas field Source 200 Kailashtilla(MSTE) gas Field Source 1090 60 Kailashtilla(Sillica) gas field Source 1089.9 30 Beanibazar Gas Field Source 1090.7 4 Haripur Gas Field Source 1088.9 1181.4 300 Bibyana Gas Field Source 1059.2 40 Kati (Titas) Source 0.005 Bakhrabad Gas Field Source 1012.2 952.71 140 APS Sink 857.39 180 GhoraPP Sink 925.51 95 HaripPP Sink 957.64 18 MymenPP Sink 935.27 52 ShiddPP Sink 1088.9 20 FenPP Sink 1086.9 36 ShahiPP Sink 1005.8 56 ZiaFF Sink 926.31 40 GhoraFF Sink 925.21 20 PalashFF Sink 881.5 45 JamuanaFF Sink 923.92 9 Joydevpur Sink 925.09 80 Gulshan Sink 853.67 40 Shirajgonj Sink 853.5 100 Baghabari Sink 1000.1 300 Ctgcity Sink 926.37 80 Sylhet Sink 925.46 110 Demra Sink 100 Khulna Sink 975.1 990 10 EP-PP Sink 70 BheraPP Sink 988 941.11 105 MeghPP Sink 143 NOMENCLATURE u= Internal energy, ft-Ibr/ Ibm V = fluid velocity, ft / sec z = elevation above a given datum place, ft p = pressure, Ibr / ft2 V = volume of a unit mass of the fluid, ftJ / Ibm W = shaft work done by the fluid on the surroundings, ft-lbr / Ibm s 2 g = gravitational acceleration, ft / sec go= conversion factor relating mass and weight h = specific fluid enthalpy, ft-Ibr / Ibm T = temperature, oR s = specific fluid entropy, ft-Ibr / Ibm pmax= maximum allowable internal pressure, psig t = pipe thickness, in c = sum of mechanical allowances, corrosion, erosion, etc., in. S = allowable stress for the pipe material, psi E = longitudinal weld joint factor, in. do= outside diameter of the pipe, in. Y = temperature de-rating factor ve= erosional velocity, ft/sec J p = Fluid density, Ibm/ft C = a constant ranging between 75 and 150 (qe)se= gas flow rate for onset of erosion, Mscfd d = diameter of the pipe, ft p = flowing pressure, PSIA R = gas constant Z = gas compressibility factor at pressure p and temperature T qsc= gas flow rate measured at saturated conditions, Mscfd psc= pressure at saturated conditions, psia Tse= temperature at saturated conditions, OR PI = upstream pressure, psia P2= downstream pressure, psi a 144 Yg = gas gravity (air = I basis) Zav= average gas compressibility factor f = Moody friction factor L = length of the pipe, ft dch= choke diameter, in T 1 = inlet temperature, oR z,~ mole fraction of vapor (gas) in the gas-liquid flow-stream c = fluid specific heat at constant pressure, Btu/Ibm-oF p )1d = Joule- Thomson coefficient, ft2-°F/lbr m = mass flow rate, Ibm/sec Q = phase-transition heat, Btu/Ibm k = thermal conductivity, Btu/ft-sec-oF do= outlet pipe diameter, ft Ts = temperature of the soil or surroundings,OF kg = Productivity index of the reservoir F = a transmission factor that is based on the flow regime and other variables, F=4Iog(3.7dlK), K is the relative roughness of the pipe Pm= the mean pressure in the pipeline Zm= the super compressibility factor at the mean pressure H = the change in elevation of the pipeline between inlet and outlet r 145 \"-, !( '-> \ '. 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