feasibility study of intelligent pigging in the ring main - BUET

FEASIBILITY STUDY OF INTELLIGENT PIGGING IN THE RING MAIN TRANSMISSION LINE OF CHATTOGRAM

MUHAMMAD REFAT NOUSHAD BHUIYA

MASTER OF PETROLEUM ENGINEERING

Department of Petroleum and Mineral Resources Engineering BANGLADESH UNIVERSITY OF ENGINEERING AND TECHNOLOGY

DHAKA-1000, BANGLADESH 09 March, 2019

FEASIBILITY STUDY OF INTELLIGENT PIGGING IN THE RING MAIN TRANSMISSION LINE OF CHATTOGRAM

A Thesis Submitted to the Department of Petroleum and Mineral Resources Engineering

In partial fulfillment of the requirements for the Degree of

MASTER OF PETROLEUM ENGINEERING

By MUHAMMAD REFAT NOUSHAD BHUIYA

Roll No: 100613013(P)

DEPARTMENT OF PETROLEUM AND MINERAL RESOURCES ENGINEERING BANGLADESH UNIVERSITY OF ENGINEERING AND TECHNOLOGY

DHAKA-1000, BANGLADESH 09 March, 2019

iv

Abstract

The project work is intended to establish the appropriateness of intelligent pigging as a

single integrity assessment tool for the ring main natural gas transmission line of

Chattogram city. For the purpose of the project work, previous cleaning pigging

operations of the ring main line were reviewed. Significant portions where important

structures/installations had grown up were identified. Records and information regarding

the physical attributes and operational issues were collected from site visits, official

documents and personal communications. Calculations were done to identify the limit of

gas withdrawal rate at different operating pressures within the practiced speed limit of an

intelligent pig. Calculations done are indicative of the ability of the ring main to allow an

intelligent pig run. Alternates of intelligent pigging were checked for their

appropriateness for adopting as an assessment tool for the ring main line. Review of

previous cleaning piggings indicates existence of metal loss issue within the ring main

line. This phenomenon is widely addressed by magnetic flux leakage (MFL) technology

based metal loss intelligent pigging operation. An MFL based intelligent pigging will

cost Tk 1,939.61 /meter on an average. Immediate rehabilitation of the ring main line

would require Tk 39,518.76/meter, Tk 75,813.13/meter, Tk 46,839.52/meter and Tk

40,822.91/meter for segment 1, segment 2, segment 3 and segment 4 respectively.

Assuming yearly 10% flat price escalation, these costs would be Tk 63,645.36/meter, Tk

1,22,097.80/meter, Tk 75,435.52/meter and Tk 65,745.71/meter for the segments

mentioned above after five years. A qualitative risk analysis indicates that the intelligent

pigging of the ring main line is a medium risk project.

v

ACKNOWLEDGEMENTS

All praise goes to the Almighty Allah, who has given the ability to fulfill the

entire work. Without His wish nothing could be done at all.

My profound gratitude and appreciation goes to Mr. Shahriar Mahmud, Assistant

Professor, Department of Petroleum and Mineral Resources Engineering, BUET for

his valuable guidance, encouragement and supervision throughout the entire work.

I would like to convey my heart-felt gratitude to Dr. Mohammad Tamim,

Professor, Department of Petroleum and Mineral Resources Engineering, BUET, for his

valuable suggestions in accomplishing this work.

I would like to thank Dr. Mohammed Mahbubur Rahman, Associate Professor

and Head, Department of Petroleum and Mineral Resources Engineering, BUET for his

valuable guidance, encouragement and supervision throughout the entire work.

I would like to express my deep gratefulness to the senior officials of KGDCL

for their invaluable cooperation in providing necessary data required for this work.

My respected mother has always been a source of inspiration in completing this

work. My beloved wife has contributed greatly by her unprecedented sacrifice and

support. My brothers have been eager to hear the completion of my degree. My

colleagues at KGDCL help their best in fulfilling this work.

vi

TABLE OF CONTENTS

Declaration iii

Abstract iv

Acknowledgement v

Table of Contents vi

List of Tables ix

List of Figures xii

Abbreviations xiii

Units and Symbols xiv

CHAPTER 1. INTRODUCTION 1

1.1 Objectives 2

1.2 Outline of Methodology 2

CHAPTER 2. BACKGROUND STUDY 3

2.1 Review of previous cleaning pigging of the ring main 3

2.1.1 First on stream cleaning pigging (1990) 3

2.1.2 Second on stream cleaning pigging (1994) 4

2.1.3 Third on stream cleaning pigging (2018) 7

2.2 Pipeline integrity management and integrity assessment 9

2.2.1 Important elements of the IM programs proposed by PHMSA 9

2.2.2 Integrity Assessment Methods Proposed by PHMSA 13

2.3 Pipeline features of the ring main 15

2.3.1 Pipeline information 15

2.3.2 Valve type 17

2.3.3 Withdrawal points/ tee connections 17

2.3.4 Major crossings 17

2.3.5 Launching and receiving facilities 17

2.4 Integrity management practices of the ring main 19

2.4.1 Routine Line Patrolling 19

2.4.2 Corrosion protection 20

vii

2.4.3 Data Collection 20

2.4.4 Maintenance actions 20

2.5 Significant portions of the ring main 20

2.5.1 Segment 1 22

2.5.2 Segment 2 22

2.5.3 Segment 3 23

2.5.4 Segment 4 24

CHAPTER 3. METHODOLOGY 27

3.1 Technical Feasibility of intelligent pigging for the ring main 27

3.1.1 Intelligent pigging 27

3.1.2 Tool speed equation 32

3.1.3 Alternates of intelligent pigging 35

3.2 Economic feasibility of intelligent pigging for the ring main 41

3.2.1 Cost of MFL based metal loss run 41

3.2.2 Cost of standard pig launcher and receiver 42

3.2.3 Cost of cleaning run 43

3.2.4 Per meter based cost calculation 44

3.2.5 Replacement cost of the ring main (provisional) 44

3.2.6 Findings/observations from the cost analysis 47

3.3 Risk analysis 48

3.3.1 Risk identification 49

3.3.2 Risk plot 49

3.3.3 Risk register 51

3.3.4 Risk matrix 53

3.3.5 Findings from risk analysis 54

CHAPTER 4. RESULTS AND DISCUSSIONS 55

CHAPTER 5. CONCLUSIONS AND RECOMMENDATIONS 59

5.1 Conclusions 59

5.2 Recommendations 60

References 61

Appendix A 64

viii

List of Valve station along the ring main 64

Gas withdrawal points 66

Appendix B 68

Spread sheet calculation for gas flow range and travel time within speed limit 68

Appendix C 84

Test water quantity calculation 84

Appendix D 85

Quotation correspondence with 3P Services 85

Appendix E 89

Cost of Pig launcher and receiver 89

Appendix F 90

Segment wise provisional materials requirement for construction of the ring main line

90

Appendix G 94

Cost of construction (provisional) of the ring main as per schedule of Petrobangla 94

ix

LIST OF TABLES

Table 2.1 Chemical analysis of sludge of 2nd cleaning pigging 5

Table 2.2 Chemical analysis of the sludge of 3rd pigging 7

Table 2.3 List of Probable Threats to a Transmission Line 12

Table 3.1 Typical composition of flowing natural gas 30

Table 3.2 Gas flow range at different pressures for segment 1 33




Table 3.6 Segment wise test water requirement 36

Table 3.7 Segment wise pond equivalent of water requirement 37

Table 3.8 Pig launcher and receiver cost 43

Table 3.9 Segment wise costs of rehabilitation (cost of materials and cost

of construction) required for the ring main transmission line

45

Table 3.10 Segment wise costs of rehabilitation required per meter for the

ring main line

46

Table 3.11 Segment wise per meter based costs of rehabilitation forecasts

up to the year 2024

47

Table 3.12 Risk register for intelligent pigging of the ring main

transmission line of KGDCL

51

Table 3.13 Percentage of risk level as per the risk matrix 54

Table A.1 List of valve stations along the route of the ring main 64

Table A.2 List of HP-DRS along the ring main transmission line 66

x

Table B.1 Operating pressure 350 psi, gas flow rate: 19-70 MMSCFD 68
















Table E.1 Cost of pig launcher and receiver 89

Table F.1 Provisional list of materials required for the construction of

19.94 km 24" 350 psi transmission line (1st segment)

90


2.57 km 16" 350 psi transmission line (2nd

segment),excluding river crossing portion

91


17.78 km 20" 350 psi transmission line (3rd segment)

excluding river crossing portions

92

xi


12.81 km 24" 350 psi transmission line (4th segment)

93

Table G.1 Provisional schedule of rates and quantities for construction of

24" 19.94 km 350 psi transmission line from CGS Fouzdarhat

to Patenga Manifold station (1st segment)

94


16" 5.07 km 350 psi transmission line from Patenga To Shah

Mirpur Manifold station (2nd segment)

98


20 inch 19.28 km 350 psi transmission line from Shah Mirpur

to BFIDC Manifold station (3rd segment)

103


24" 12.81 km 350 psi transmission line from BFIDC manifold

station to CGS Fouzdarhat (4th segment)

108

xii

LIST OF FIGURES

Figure 2.1 Fouzdarhat CGS manifold station. 18

Figure 2.2 Shah Mirpur manifold station. 19

Figure 2.3 Ring main transmission line on geographic map 21

Figure 2.4 Position of ring main line at the CEPZ area. 22

Figure 2.5 Positions of river crossing, CUFL and KAFCO in segment 2 23

Figure 2.6 Positions of road crossing, industrial installations and canal

crossing in segment 3

24

Figure 2.7 Position of 20” Karnaphuli river crossing in segment 3 24

Figure 2.8 Positions of rail crossing, road crossing and Kalurghat

heavy I/A in segment 4

25

Figure 2.9 Positions of rail crossing, road crossing and vicinity of

Chattogram cantonment area in segment 4

25

Figure 2.10 Positions of rail crossing, road crossing near the Fouzdarhat

CGS in segment 4

26

Figure 3.1 Ring main transmission line with physical features 29

Figure 3.2 Risk plot with indication of different risk levels and risk scores 50

Figure 3.3 Risk matrix with risks qualitatively assessed and mapped

for intelligent pigging of the ring main line

53

Figure D.1 Quotation related document 85

Figure D.2 Quotation related document. 86



xiii

ABBREVIATIONS

API American Petroleum Institute

ASME American Society of Mechanical Engineers

CEPZ Chittagong Export Processing Zone

CGS City Gate Station

CIS Close Interval Survey

CMS Customer Metering Station

CUFL Chittagong Urea Fertilizer Limited

DRS District Regulating Station

ECDA External Corrosion Direct Assesment

EPZ Export Processing Zone

ERW Electric Resistance Weld

GTCL Gas Transmission Company Limited

HCA High Consequence Area

HP-DRS High Pressure District Relgulating Stations

ILI In line Inspection

IM Integrity Management

KAFCO Karnaphuli Fertilizer Company

KGDCL Karnaphuli Gas Distribution Company Limited

LNG Liquefied Natural Gas

MAOP Maximum Allowable Operating Pressure

MFL Magnetic Flux Leakage

NACE National Association of Corrosion Engineers

xiv

NDE Non Destructive Examination

PHMSA Pipeline and Hazardous Material Safety Administration

PIG Pipeline Inspection Gauge

POD Probability of Detection

R-LNG Re-gasified Liquefied Natural Gas

ROW Right of Way

SCC Stress Corrosion Cracking

SWOT Strengths, weaknesses, opportunities and threats

TEG Thermo electric generator

UNITS and SYMBOLS

Cft Cubic Feet

Km Kilometer

MMSCFD Million Standard Cubic Feet per Day

Psi Pounds/sq. inch

Tk Taka

€ Euro

1

CHAPTER 1: INTRODUCTION

Natural gas is distributed to the city of Chattogram by a segmented multi diameter

circular high pressure pipe line network known as the ring main line. This line is operated

by the Karnaphuli Gas Distribution Company Limited (KGDCL), a company under

Petrobangla. Since its commissioning, the ring main line has reached 35 years of

continuous operation. It is a matter of great concern that the line has not undergone any

integrity assessment program yet.

According to the Pipeline and Hazardous Material Safety Administration

(PHMSA) of USA, there are four integrity assessment techniques, namely pressure

testing, in line inspection (ILI)/ intelligent pigging, direct assessment and other

technologies (National Transportation Safety Board, 2015).

ILI/intelligent pigging provides the information required for the majority of

inspection and troubleshooting needs for pipelines. The two most common ILI services

are: metal loss and geometry measurement (Cordell and Vanzant, 2003). The most

proven and mature technology used in ILI services is magnetic flux leakage (MFL).

Other technologies are ultrasonic, eddy current, electromagnetic acoustic transducer

(EMAT) etc.

The ring main line has undergone three cleaning type pigging operations till date.

The intervals of these pigging operations are astonishingly irregular. However, sludge

analyses of these operations indicate presence of metal loss phenomenon within the ring

main line. Therefore, economic implication of MFL technology based metal loss

intelligent pigging is focused in the work. On the other side, technical analysis and a

qualitative risk analysis is done in a rather generalized manner.

2

1.1 Objectives

To assess the current physical condition of the ring main

To establish the appropriateness of intelligent pigging as a single integrity

assessment tool for the ring main line.

1.2 Outline of Methodology

Collection of information through

o Reports

o Personal communication

o Site visits

Evaluate the technical compatibility of the ring main line for an intelligent

tool run in terms of physical and operational features of the ring main.

Examine if there were any alternative integrity assessment methods.

Evaluate all solution options in terms of cost, time, degree of difficulty,

environmental and safety issues etc.

3

CHAPTER 2: BACKGROUND STUDY

2.1 Review of previous cleaning pigging of the ring main

So far, the ring main has undergone three cleaning pigging programs. It is notable

that the programs were done at irregular intervals. For getting necessary impetus for

adopting intelligent pigging as an appropriate and urgent integrity assessment tool for the

ring main, the previous cleaning type pigging are reviewed.

2.1.1 First on stream cleaning pigging (1990). The ring main line came into

operation on 1984. From the inception, with the inclusion of various categories of

customers (power, fertilizer, other industrial, commercial and domestic), the supply of

natural gas was on increasing. Condensate entrained with natural gas (initially at gaseous

state) started to accumulate at the lower points of the pipelines. With the increasing

demand of gas and gas velocity, the cumulative amount of condensate caused surging at

the City Gate Station (CGS) and the Customer Metering Stations (CMS) of the big

industrial customers located downstream and disruption of continuous supply was

experienced. In that perspective, program for on stream pigging (cleaning) was planned.

The first on stream cleaning pigging was done on 9-15th July 1990 (BKB-CTG pipe line

and the ring main line).

After the successful completion of the pigging operation an amount of 7,11,000

liter condensate (BKB-CTG pipeline + ring main) were collected at the CGS, Fouzdarhat.

It is to be noted that this operation was done during yearly Over Hauling of the

Chittagong Urea Fertilizer Limited (CUFL).

No information regarding recommendations is available.

4

2.1.2 Second on stream cleaning pigging (1994). According to Bakhrabad Gas

Systems Limited (1994), gas transmission was comparatively sound until January, 1993.

During this period, no sign of improvement in the quality of gas was observed. Produced

gas from Bakhrabad field at higher temperature (120-1300F), entrained condensate at

gaseous state had got condensed at some distance at ground temperature (85-900F) and

started to accumulate at the lower points of the pipeline. The accumulated condensate in

the form of slug moved towards CGS resulting in surging. By this time, Feni gas field

also had started production. The 210 MW thermal power plant was commissioned and

increasing number of gas consumers resulted in transmission of 160-165 MMSCFD of

gas which was 47% of design capacity of the pipeline. Hence, the factor of higher rate of

gas flow along with higher amount of condensate and with the increase in gas velocity,

huge amount of condensate was depositing at the CGS plant. This time other elements

such as the silica gel from process plant, the corroded part of the pipeline and residue of

liquid hydrocarbon were also found. All this unwanted objects posed tremendous

operational disorder in the CGS. Moreover, the huge amount after crossing the CGS

surged different HP-DRS and Bulk Customers located at the ring main caused multiple

disruption in gas supply especially at CUFL. Important parts of CGS such as pilot,

regulator, transmitter, metering skid of bulk customers were subjected to repeated

maintenance works. Under these circumstances, to maintain the integrity of the

transmission system, second on stream pigging program was scheduled. It was assumed

that huge amount of condensate was accumulated in the pipeline as sample observed in

the CGS plant and the CMS of big industrial customers. It was considered that keeping

all the customers on stream would be risky for the pigging operation. During that time

5

CUFL, 210 MW thermal power plant and 60 MW Shikolbaha power plant were the main

consumers. Simultaneous shutdown of all these would be practically impossible.

However, considering possible risk on plant operation and shutdown of gas supply, an

inter-secretariat meeting including members from BCIC, PDB and Petrobangla was held

and the then honorable additional secretary approved pigging schedule on 03-02-94. It

was executed from 6-9th February 1994. During pigging operation, total 3,87,000 liter

condensate and 2,690 Cubic feet sludge was collected (BKB-CTG pipeline + ring main).

In The second time pigging of the then Bakhrabad Gas Systems Limited (BGSL),

unexpected amount of sludge was collected and sample of which was examined in

BUET, BAPEX, ERL and Bakhrabad gas field. The test results are reproduced in Table

2.1.

Table 2.1

Chemical analysis of sludge of 2nd

cleaning pigging

Sl No. Element BUET BAPEX ERL BKB Lab

1 Carbonaceous substance

(organic) % wt 55.09 38.79 41.322 N/A

2 Dust of Silica Gel % wt - 0.96 0.458 0.458

3 Sand/Mud % wt 9.16 23.03 26.113 26.113

4 Mill Scale (Rust) as Fe2O3 % wt 25.10 30.22 23.097 23.097

5 Mud and Other Identified

Substances % wt 10.65 07.00 - -

Note. Reprinted from On-stream pigging completion report and recommendations,

Bakhrabad Gas Systems Limited, 1994, Cumilla, Bangladesh.

6

Observations regarding the 2nd

pigging. The observations of the 2nd pigging are

as follows:

1. Huge amount of sludge recovery comparing to the 1st pigging.

2. Flow of Silicon dioxide (SiO2) with natural gas at high pressure caused sand

blasting type erosion of the pipeline.

3. Water flow in excess reacts with CO2 to form H2CO3 which might cause

corrosion of the pipeline.

4. Carbon (C) in mild steel pipeline in presence of water act as a cathode while the

iron (Fe) acts as anode allowing formation of local Galvanic cell to cause

corrosion.

Recommendations of the 2nd

pigging. The recommendations of the 2nd pigging

are as follows:

1. Flow of gas at ground temperature from the process plant.

2. Investigation should be done regarding the source of SiO2 in pipe line to make

necessary renovation of the process plant.

3. Pipe line internal should be inspected by intelligent pigging due to corrosion and

erosion. Otherwise explosion of high pressure gas line may cause huge loss of life

and property.

4. Inform BGFCL to maintain the quality of gas in specified standards.

7

2.1.3 Third on stream cleaning pigging (2018). After the second pigging of the

ring main, due to different unavoidable circumstances, a huge gap has been created to

perform on stream pigging of the pipe line. However, before inclusion of re-gasified

liquefied natural gas (R-LNG) in the KGDCL network, it had become inevitable to

perform another cleaning pigging of the ring main. This time, the project was done by a

third party. This cleaning pigging was done from 27-29th July 2018. After completion of

the pigging operation, about 1000 gallons of sludge was collected.

Chemical analysis of sludge. The chemical analysis of the sludge was done in

BUET. The analysis results are reproduced in Table 2.2.

Table 2.2

Chemical analysis of the sludge of 3rd

pigging

Sl No. Test parameters Results Unit Method

1 Total moisture 2.55 wt %

ASTM D 3172 2 Volatile matter 22.03 wt %

3 Fixed Carbon content 20.89 wt %

4 Ash content 54.53 wt %

5 Sulfur content 0.91 wt % ASTM D 3177

6 Calorific value 2885 kcal/kg ASTM D 5865

7 Iron (Fe) content 43.0 wt %

Spectrophotometric

method

8 Magnesium (Mg) content 23.56 wt %

9 Calcium (Ca) content 5.89 wt %

10 Silica (SiO2) content 3.71 wt %

11 Arsenic (As) content Nil Ppb

(continued)

8

Sl No. Test parameters Results Unit Method

12 Copper strip corrosion (10%

aqueous slurry of the sample)

1b Slight

tarnish - ASTM D 130

13 Water solubility (Dissolved in

distilled water) 32.44 wt %

Gravimetric analysis 14 Acid solubility (Dissoloved in

concentrated HCl) 82.9 wt %

15 Base solubility (Dissolved in

2N NaOH) 52.7 wt %

16 pH@ 29.4 0C (10% aqueous

slurry of the sample) 7.7 - pH meter

Note. Reprinted from On-stream pigging completion report and recommendations of 57

km multi diameter ring main line of Karnaphuli Gas Distribution Company Limited,

Libra Enterprise, 2018, Chattogram, Bangladesh.

Recommendations of the 3rd

pigging. The recommendation of the 3rd pigging are as

follows:

1. Installation of standard pig launchers and receivers with quick opening door and

proper pressure equalizer and kicker lines for ease of pigging in future.

2. Run intelligent pig to see the condition of the pipe line especially possible

thinning of pipe wall, its allowable operating pressure and any other defect that

would seriously affect the integrity of the pipeline in future.

Table 2.2 (continued)

9

3. Should closely coordinate with GTCL to ensure the pressure of the ring main at

300 psi or below.

(Libra Enterprise, 2018)

2.2 Pipeline integrity management and integrity assessment

Ensuring Transmission Pipeline safety and environmental protection in areas of

High population density and in areas sensitive to environmental damage is an inevitable

need. Pipeline related incidents worldwide suggest pipeline operators/companies to

enforce stringent integrity management plan for the safety of their pipeline.

U.S.A’s Pipeline and Hazardous Material Safety Administration (PHMSA) enact

Integrity Management Regulations as a result of several Pipeline incidents throughout the

year from 1991-2000. Employment of this regulations are destined for providing

enhanced protection for areas with human inhabitant and structures which are under risk

in case of pipeline failure. The regulations include a mix of performance-based and

prescriptive requirements, with the intent of providing sufficient flexibility to reflect

pipeline-specific conditions and risks without imposing unnecessary burdens on

operators. The regulations require gas transmission pipeline operators to develop an IM

program for their pipeline segments located within an HCA (National Transportation

Safety Board, 2015).

2.2.1 Important elements of the IM programs proposed by PHMSA.

According to National Transportation Safety Board (2015), important elements of the IM

programs proposed by PHMSA are as follows:

i. High consequence area (HCA) identification: the process of determining those

portions of a pipeline system for which a failure would have the highest impact.

10

ii. Threat identification, data integration, and risk assessment: the process of using

all available information to determine which failure mechanisms each pipeline

segment within an HCA is susceptible to and then estimating the risk of pipeline

failure due to these mechanisms; pipeline segments are ranked according to their

risks to create a prioritized schedule for integrity assessments, in which pipeline

segments are inspected or tested to verify their integrity.

iii. Baseline assessment plan: the first schedule for completing integrity assessments,

including the selection of assessment method(s) appropriate to the threats

identified; a baseline assessment plan must also be completed whenever new pipe

is installed or a new HCA is identified.

iv. Direct assessment: one method of integrity assessment, used only for assessing

corrosion threats; a direct assessment plan is required only if an operator uses this

assessment method. Other integrity assessment methods are allowed, such as

pressure testing and in-line inspection (ILI). The requirements regarding the

selection and use of these methods are included in the program elements of

baseline assessment plan and continual evaluation and assessment.

v. Confirmatory direct assessment: a direct assessment method used for integrity re-

assessments.

vi. Remediation: the process of repairing or replacing pipeline defects found during

integrity assessments.

vii. Preventive and mitigative (P and M) measures: actions which lower the likelihood

(preventive measures) or reduce the consequences (mitigative measures) of a

11

pipeline failure. P and M measures are used to reduce the risk of some threats that

cannot be assessed.

viii. Continual evaluation and assessment: the ongoing practice of repeating each of

the processes described above, including the schedule and methods for integrity

reassessments, to ensure the continued integrity of a pipeline.

Each operator’s IM program must contain supporting plans and procedures

covering performance measures, recordkeeping, and management of change, quality

assurance, communication and documentation.

PHMSA requires pipeline operators to identify and evaluate all potential threats to

each HCA. ASME B31.8S, one of the standards referenced in the PHMSA requirements,

describes three general threat types that must be considered. Each general threat type has

three specific threat categories. Additionally, operators must consider interactions among

these different threats, as well as the effects of metal fatigue, if applicable. Table 2.3

provides a listing of these threat types and associated threat categories.

12

Table 2.3

List of Probable Threats to a Transmission Line

Threat Type Threat Category Description

Time Dependent

Internal Corrosion Deterioration of pipeline Due to interaction with pipeline

material and inside environment of the pipeline

External Corrosion Deterioration of pipeline Due to interaction with pipeline

material and outside environment of the pipeline

Stress Corrosion

Cracking

Cracks in the pipe wall due to interaction of tensile

stresses in the pipe material with a corrosive environment.

Stable

Manufacturing Defects incorporated since manufacture of the pipeline

such as laminations, inclusions, hard spots, manufacturing

technique which is now considered have weakness (low

frequency electric resistance welded pipe, lap weld, butt

weld

Construction Defects and weakness during construction bad field weld,

wrinkle bends, stripped threads and broken pipe.

Equipment Equipments other than pipe, such as Pressure control and

relief valve, gasket, O-ring, seals

(continued)

13

Time

Independent

Third

Party/Mechanical

Accidental and intentional excavation damage

Incorrect Operation Incorrect operation by operators

Weather Related Earth movement, seismic events, heavy rain fall, erosion,

cold, lightning etc.

Note. Reprinted from Integrity Management of Gas Transmission Pipelines in High

Consequence Areas by the National Transportation Safety Board, 2015

https://www.ntsb.gov/safety/safety-studies/Documents/SS1501.pdf). National

Transportation Safety Board.

2.2.2 Integrity Assessment Methods Proposed by PHMSA. IM regulations by

PHMSA describe four integrity assessment methods. Depending upon the threats to and

characteristics of the pipeline, it is the operator’s responsibility to adopt the appropriate

method. Primarily, these integrity assessment methods are targeted toward detecting

defects tied to some threats namely corrosion and manufacturing defects but not others

(for example, equipment failure and incorrect operations), which are addressed by

preventive and mitigative measures. The four allowed assessment methods are:

i. In-line Inspection (ILI):

ILI is an internal pipeline inspection technique that uses magnetic flux

leakage, ultrasound, eddy current, or other sensing technology to locate and

characterize indications of defects, such as metal loss or deformation in the

pipeline. The sensor is mounted on a device (known as a “smart PIG”), which is


https://www.ntsb.gov/safety/safety-studies/Documents/SS1501.pdf

14

inserted into the pipeline segment between a launching station and a receiving

trap. The smart PIG moves through the pipe scanning the pipe for specific types

of defects. Pipeline segments that can accommodate ILI tools are considered

“piggable”. Different sensors are used for different defects.

ii. Pressure Testing:

A pressure test can be used as a strength or leak test. A common type of

pressure test is a hydrostatic test, which involves taking the pipeline out of service

and pressurizing a section of pipe with water to a much higher percentage of the

pipe material's maximum design strength than the pipe will ever operate at with

natural gas. This verifies the capability of a pipeline to safely operate at the

MAOP and can reveal weaknesses that could lead to defects and leaks in the pipe.

Pressure testing of pipelines is designed to find critical seam defects (as well as

other defects caused by corrosion, stress corrosion cracking and fatigue) by

causing the pipe to fail at these critical defect-locations.

iii. Direct Assessment:

Direct assessment relies on the examination of the pipeline at pre-selected

locations to evaluate a pipeline for external corrosion, internal corrosion, or stress

corrosion cracking threats. Most of the pipeline segment being inspected is

usually not directly examined. Direct assessment uses multiple steps (four steps

for external and internal corrosion, and two steps for stress corrosion cracking).

For example, for external corrosion direct assessment (ECDA), the steps are

(NACE 2008): pre-assessment (the operator determines the feasibility of ECDA,

determines ECDA regions, and selects tools for indirect inspection), indirect

15

inspection (the operator conducts above-ground inspections, such as a close

interval survey (CIS), to identify and classify indicators of corrosion and pipe

coating defects), direct examination (the operator excavates the pipe at selected

locations to measure actual corrosion damage), and post-assessment (the operator

determines reassessment intervals and evaluates the effectiveness of the ECDA

process).

This-method-requires-the identification of regions within the pipeline

segments for excavation and direct examination. Therefore, even though a

pipeline segment may be inspected with direct assessment, only-a-small-sub-

segment-is-directly-examined.

iv. Other Technologies:

These technologies include methods that are industry-recognized,

approved, and published by an industry consensus standards organization or other

methodologies that follow performance requirements with documentation. One

example is guided wave ultrasonic. Operators must inform PHMSA 180 days

before an assessment if they are using these other methodologies-and-

technologies.

2.3 Pipeline features of the ring main

2.3.1 Pipeline information. The entire ring main line consists of four segments.

The segment wise information is as follows (KGDCL, personal communication, August,

2018):

Segment 1: Fouzdarhat CGS to Patenga manifold station.

Length: 19.94 km

16

Diameter: 24 inch.

Wall thickness: 0.344 inch.

Pipe manufacturing process: ERW

Pipe specification: API 5LX 56

Segment 2: Patenga manifold to Shah Mirpur manifold station.

Length: 5.07 km

Diameter: 16 inch.



Pipe specification: Grade B

Segment 3: Shah Mirpur manifold to BFIDC manifold station.

Length: 19.28 km

Diameter: 20 inch.



Pipe specification: Grade B

Segment 4: BFIDC manifold to Fouzdarhat CGS.

Length: 12.81 km

Diameter: 24 inch.



Pipe specification: API 5LX 56

17

2.3.2 Valve type. Segment wise valve numbers are as follows:

Segment 1: Fouzdarhat CGS to Patenga manifold station.

No. of valve stations: 03 (ANSI 300 class)

Segment 2: Patenga manifold to Shah Mirpur manifold station.


Segment 3: Shah Mirpur manifold to BFIDC manifold station.


Segment 4: BFIDC manifold to Fouzdarhat CGS.


List of valve stations are placed in Appendix A.

2.3.3 Withdrawal points/ tee connections. List of withdrawals points (HP DRS)

and off take stations are provided in Appendix A. All the T-connections from each

segment to withdrawal points (HP DRS/CMS) and off take points are fitted with guide

bar which prevent stuck up of ILI tool.

2.3.4 Major crossings. Number of significant crossings is as follows:

Highway: 04

River: 03

Railway: 04

2.3.5 Launching and receiving facilities. There are four manifold stations in the

ring main line. These are:

1. CGS manifold (24///20//)

2. Patenga manifold (24///16//)

3. Shah Mirpur manifold (20///16//)

18

4. BFIDC manifold (24///20//)

It was noted that there is no regular launching and receiving facilities in the manifold

stations. Existing Receivers and launcher barrels are flanged extension of main line pipe.

But there are provisions for setting up standard receiving and launching facilities. So far,

the ring main line is cleaned thrice since its inception. Each time, necessary

fabrication/modification was done in the manifold stations for pig launching and

receiving. Two pig launching and receiving stations at CGS,Fouzdarhat and Shah Mirpur

are shown in Figure 2.1 and Figure 2.2.

Figure 2.1. Fouzdarhat CGS manifold station (KGDCL, personal communication, July,

2018).

19

Figure 2.2. Shah Mirpur manifold station (KGDCL, personal communication, July,

2018).

2.4 Integrity management practices of the ring main

Operation division of KGDCL is responsible for maintaining the transmission

network. There are different sections in the division for looking up specified actions. The

regular jobs are line patrolling, corrosion protection check up, data collection etc

(KGDCL, personal communication, February, 2018).

2.4.1 Routine Line Patrolling. Staffs are employed for patrolling the

transmission line regularly. There are marker posts along the line and one patrol man is

employed for one marker post to the immediate marker post spanning a distance of 4-5

kilometers. A patrol man checks for any illegal installation, excavation or any other

unusual incidents along the pipeline Right of Way (ROW). Any unusual activity is

20

immediately reported to the controlling officer for necessary steps. After completing

patrolling of the concerned distance, the next patrolling is initiated by another patrol man

and this manner continues until the patrolling reaches the beginning position. It takes 1-

1.5 days to complete full patrolling of the transmission line.

2.4.2 Corrosion protection. The outer surface of the ring main line is coated

with polyethylene tape (inner and outer wrap) and primer to protect against corrosion.

Moreover, cathodic protection (CP) system with impressed current and sacrificial anode

at different points of the ring main line have also been deployed. But there is no

protruding type corrosion monitoring probe which can act as an obstruction to the ILI

tool passage. Inspection team periodically collecting reading from the CP post and

analyze for any immediate action.

2.4.3 Data Collection. Staffs are employed at the CGS, different TBS’s for

taking the hourly pressure, flow readings and reporting the controlling authority over

telephone.

2.4.4 Maintenance actions. Necessary maintenance work like greasing of

valves, coloring DRSs etc. is done as per requirement of the authority.

2.5 Significant portions of the ring main

During the planning phase of the ring main, it was designed to surround the City

of Chattogram. Hence, the right of way of the pipe line was chosen to move through

places without human inhabitant or industrial installations. However, in the later times,

without the presence of marker posts along the route of the ring main line, human

inhabitants were built. Industrial installations at some points were also established. This

matter was taken into consideration by the related division of KGDCL and action plans

21

were undertaken to eradicate human inhabitants along the ROW of the pipe line. For

industrial installation situated in the EPZ, box culverts were constructed over the

transmission line. In this chapter, significant installations like industrial concerns, rail

crossing, road crossings, and river crossing etc. along the ROW of the ring main were

marked. It is mentionable that any failure of the ring main at these points might results in

severe loss of life and property as well as indispensable rehabilitation of the ring main.

Figure 2.3 illustrates the position of the ring main on geographic map (KGDCL, personal

communication, October, 2018).

Figure 2.3. Ring main transmission line on geographic map.

22

2.5.1 Segment 1. The significant locations at segment 1 are one rail crossing, one

road crossing and the Chattogram export processing zone (CEPZ). With the extension the

EPZ area, some industrial installations were constructed in positions situated at the outer

side of the ring main. Industries with entry points close to the ring main have constructed

box culverts as directed by relevant division of KGDCL. It is worth mentioning that any

transmission line failure in this area may cause severe consequences. Figure 2.4 is an

extraction from Figure 2.3 showing the portion of segment 1 with significant

installations.

Figure 2.4. Position of ring main line at the CEPZ area.

2.5.2 Segment 2. The significant locations at this segment are 16” 2.5 km

Karnaphuli river crossing and offtake points to two fertilizer factories (CUFL and

KAFCO). Pipe line failure at river crossing would require complete construction of the

1. 24” transmission line 2. CEPZ area

23

concerned pipeline section. Figure 2.5 is an extraction from Figure 2.3 showing the

portion of segment 2 with significant installations.

Figure 2.5. Positions of river crossing, CUFL and KAFCO in segment 2.

2.5.3 Segment 3. This segment contains Chattogram-Cox’s Bazar highway

crossing, some industrial installations and khal crossing (Figure 2.6) and 1.5 km 20”

river crossing (Figure 2.7 extracted from Figure 2.3). Pipe line failure at river crossing

would require complete construction of the concerned pipeline section.

1. 16” transmission line 2. Karnaphuli river crossing 3. CUFL 4. KAFCO

24

Figure 2.7. Position of 20” Karnaphuli river crossing in segment 3.

2.5.4 Segment 4. The significant points at this segment are three rail crossings,

two road crossings, Kalurghat heavy industrial area, approach to Chattogram cantonment

etc. (Figure 2.8, 2.9, 2.10 extracted from Figure 2.3).

1. Karnaphuli river crossing 2. Location industrial

installations 3. 20” transmission line

Figure 2.6. Positions of road crossing, industrial installations and canal crossing in segment 3.

1. Kalar khal crossing 2. Location industrial

installations 3. Ctg-Cox’s Bazar road

crossing 4. 20” transmission line

25

Figure 2.8. Positions of rail crossing, road crossing and Kalurghat heavy I/A in

segment 4.

Figure 2.9. Positions of rail crossing, road crossing and vicinity of Chattogram

cantonment area in segment 4.

1. Cantonment 2. Road crossing 3. Rail crossing 4. 24” transmission line

1. Rail crossing 2. Road crossing 3. 24” transmission line 4. Kalurghat heavy industrial

area

26

Figure 2.10. Positions of rail crossing, road crossing near the Fouzdarhat CGS

in segment 4.

1. Rail crossing 2. 24” transmission line

27

CHAPTER 3: METHODOLOGY

3.1 Technical Feasibility of intelligent pigging for the ring main

The available integrity assessment methods are ILI, pressure testing, direct

assessment and other technologies as described in Chapter 2. Since its inception, the ring

main line has not experienced any integrity assessment procedure. Different factors such

age of the pipe line, previous cleaning type pigging data analysis, determination of

maximum operating pressure and flow etc. have make it inevitable to assess the integrity

of the main transmission backbone of Chattogram.

In process of proposing the appropriate integrity assessment tool for the ring main

line, the methods proposed by PHMSA are examined for their applicability, physical and

operational constraints, degree of uncertainty, time, environmental impacts etc.

3.1.1 Intelligent pigging. The matters that must be considered for adopting an ILI

tool run are the physical and operational compatibility of the concerned pipeline. In

pipeline industry this issue is known as “piggability”. Piggability implies the ability of a

pipeline to enter and exit of a pig without damage to the pipeline or the tool used. In the

context of the project work, a piggable pipe line means a pipe line suitable for the

economic operation of a gas driven, instrumented in line inspection tool. Within the

context of this definition, it is also assumed that the pipe line internal conditions and

operating parameters are such that acceptable inspection results suitable for integrity

assessment can be obtained.

Physical issues. It involves the available facilities/adaptability of the ring main

for intelligent pigging and additional requirement (if any).

28

Facilities available. Physical compatibility issues include the nature of pipe line

details (length, diameter, wall thickness data, specification, and manufacturing process),

valve type, corrosion protection system; withdrawal points/tee connections, major

crossings, pig/ILI tool receiving and launching facilities etc (API, 2013).

Studies imply that the physical features of the ring main are eligible for an

intelligent pig run. The delivery line valves are full bore. There is no tight bends which

restricts easy passage of ILI tool.

Facilities required. Before attempting pig/ILI tool run, standard launching and

receiving facilities should be incorporated in the manifold stations (NACE International,

2010). Access to the launching and receiving/manifold stations should be made

approachable for ILI tool handling vehicle.

Figure 3.1 shows the ring main line with indications of transmission line features

and gas distribution zones of KGDCL (KGDCL, personal communication, September,

2018).

29

Figure 3.1. Ring main transmission line with physical features (KGDCL, personal communication, September, 2018).

30

Operational issues. Operational compatibility issues include the flowing fluid

type, line pressure, temperature, flow rate, tool speed etc (API, 2013).

Fluid type. The ring main line carries natural gas. Composition of the gas from

chromatograph analysis is shown in Table 3.1 (KAFCO, personal communication,

September 18, 2018) :

Table 3.1

Typical composition of flowing natural gas

Sl no. Name of component Vol %

1 Methane (CH4) 93.247

2 Ethane (C2H6) 6.574

3 Propane (C3H8) 0.024

4 Iso-butane (i-C4H10) 0.00

5 n-butane (n-C4H10) 0.00

6 Iso-pentane (i-C5H12) 0.00

7 n-pentane (n-C5H12) 0.00

8 Carbon dioxide (CO2) 0.00

9 Argon (Ar+O2) 0.003

10 Nitrogen (N2) 0.152

11 Sulfur (H2S) -

Note. Reprinted from KAFCO cms gas chromatograph analysis (KAFCO,

personal communication, September 18, 2018)

31

Compositional analysis shows that there is no sulfur content in the gas transmitted

by the ring main. Hence, there is no corrosiveness is the gas. Average specific gravity is

0.596.

Line pressure. The maximum allowable operating pressure of the ring main is

350 psi. But it has been operated below the MAOP. Before the advent LNG, there had

been crises for both flow rate and pressure. As the initial period of LNG is ongoing, still

some irregularities are experienced. But soon, supply management would be stable. Then

pressure requirement for ILI tool run would not be a problem.

Temperature. The flowing temperature of natural gas thru the ring main is

maintained at 60 0F as contracted. The allowable temperature range for pig/ILI tool is 32

0F to 180 0F (Wint, 2011). So, the flowing temperature would not be a problem for ILI

tool run.

Flow rate. It is reported that maximum capacity of the ring main is 350

MMSCFD. The flowing gas in the ring main is distributed (after regulation to 150 psi) by

number of HP DRSs and CMSs to different industrial, power, fertilizer, commercial,

domestic customers. It is found that there is no segment wise flow measurement system

in the ring main. The concerned department of KGDCL provided the amount of

maximum daily flow by HP DRSs and some major industrial offtakes.

During cleaning pigging, usually the offtake points, HP DRSs and CMSs of the

concerned segment are kept closed for preventing influx of sludge/condensate to the 150

psi network and for maintaining stable pig run.

32

3.1.2 Tool speed equation. The following formula provides a close

approximation of the velocity of pig/ILI tool (T.D. Williamson, 2016, p. 31):

Where,

Q = flowrate in MMSCFD

Pb = Absolute base pressure in psi = 14.69 psi

P = Absolute line pressure in psi

Fpv = Supercompressibility Factor

d = inside diameter of pipe in inch

Typical speed for ILI tool is 2-7 mph (Wint, 2011). Maintaining a constant speed

enables good data gathering by the ILI tool. Segment wise pressure and flow should be

maintained is such a way that the ILI tool run within the specified limit.

Calculation. Maintaining a stable flowing pressure and gas flow that allow ILI

tool run within limit is crucial for achieving good data gathering of the concerned pipe

segment. The segment wise gas flow regime allowing the tool to be run within the

practiced speed limit and time requirement for run completion is done by excel spread

sheeting at different flowing pressure. Following assumption are made in the calculation:

1. Specific gravity of flowing gas = 0.6.

2. Flowing temperature being constant at 60 0F.

3. Stable flowing pressure throughout the concerned segment.

4. Stable flow of fluid

5. Base pressure of 14.69 psi.

33

Segment wise gas flow range at different flowing pressures within the practiced

speed limit of ILI tool are summarized in the following tables. Spread sheet calculations

at different pressures for segment 1-4 are placed in Appendix B.

Segment 1: CGS to Patenga manifold. The flow range and travel time

requirement for segment 1 at different flowing pressure conditions are summarized in

Table 3.2.

Table 3.2

Gas flow range at different pressures for segment 1

Sl no. Operating Pressure,P

(psi)

Flow Range

(MMSCFD)

Travel time

(hr)

1 350 19.50 - 68.20

6.24 - 1.78 2 300 16.55 - 58.00

3 275 15.10 - 52.95

4 250 13.70 - 47.95

Segment 2: Patenga to Shah Mirpur manifold. The flow range and travel time


Table 3.3.

34

Table 3.3



(psi)

Flow Range

(MMSCFD)

Travel time

(hr)

1 350 08.65 – 30.25

1.58 – 0.45

2 300 07.35 – 25.70

3 275 06.70 – 23.46

4 250 06.06 – 21.25

Segment 3: Shah Mirpur to BFIDC manifold. The flow range and travel time


Table 3.4.

Table 3.4



(psi)

Flow Range

(MMSCFD)

Travel time

(hr)

1 350 13.50 – 47.25

6.01 – 1.72

2 300 11.50 – 40.20

3 275 10.50 – 36.70

4 250 09.50 – 33.20

35

Segment 4: BFIDC to CGS manifold. The flow range and travel time requirement

for segment 4 at different flowing pressure conditions are summarized in Table 3.5.

Table 3.5



(psi)

Flow Range

(MMSCFD)

Travel time

(hr)

1 350 19.50 - 68.20

4.00 - 1.14

2 300 16.55 - 58.00

3 275 15.10 - 52.95

4 250 13.70 - 47.95

3.1.3 Alternates of intelligent pigging. According to PHMSA, there are three

alternatives of intelligent pigging, namely pressure testing, direct assessment and other

technologies. For the purpose of this project, different aspects regarding the

appropriateness of the alternatives (excluding the other technologies for lack of its wide

applicability) of intelligent pigging to be applied for integrity assessment of the ring main

are studied.

Pressure testing. The most common mode of pressure testing is hydro testing.

Aspects such as physical, operational, safety and environmental issues related to pressure

testing for the ring main reveal its inappropriateness for adopting as an integrity

assessment tool.

36

Physical issues. Pressure test can be done separately for the four segments of the

ring main line if it is adopted for integrity assessment for the ring main. Segment wise

test water requirement is shown in Table 3.6.

Table 3.6

Segment wise test water requirement

Sl no. Segment name Length

(km)

Pipe line dia

(inch)

Water requirement

(barrel)

1. CGS Fouzdarhat to Patenga

manifold station

19.94 24 46514.43

2. Pateng to Shah Mirpur

manifold station

5.07 16 5228.47

3. Shah Mirpur to BFIDC

manifold station

19.28 20 31069.82

4. BFIDC manifold station to

CGS Fouzdarhat

12.81 24 29882.14

Sample calculation for test water requirement are placed in Appendix C. The

amount of water required for testing each segment of the ring main is equivalent to big

water bodies like ponds (Kiefner, & Maxey, 2013). The segment wise dimension of the

equivalent water bodies are placed in Table 3.7.

37

Table 3.7

Segment wise pond equivalent of water requirement

Sl no. Segment name Water requirement

(barrel)

Pond equivalence for

the required water

1. CGS Fouzdarhat to

Patenga manifold

station

46514.43 100 100 ft pond with

19.4 ft of depth

2. Patenga to Shah Mirpur

manifold station

5228.47 50 50 ft pond with

8.7 ft of depth


manifold station

31069.82 100 100 ft pond with

12.9 ft of depth

4. BFIDC manifold station

to CGS Fouzdarhat

29882.14 100 100 ft pond with

12.5 ft of depth

Karnaphuli river may be considered as the source of water if the manifold stations

closer to the river are planned for line filling. But before line filling, the water quality

should be treated for corrosion inhibition, pH neutralization and other necessary

requirements such as TDS, total suspended solids etc. It is to be kept in mind that the

amounts of water required mentioned are excluding makeup requirements and failure

contingency. Therefore, segment wise test water storage amount would be higher.

Facility requirement for storing and treating such huge amount of test water is also a

significant spatial, strategic and financial issue. After test completion, disposal of water

should be done as per environmental regulation of government of Bangladesh.

38

Operational issues. Issues like supply disruption, adoption of test pressure, time

requirement are found incompatible for adopting pressure test as integrity assessment tool

for the ring main.

i. Supply disruption: The concerned segment planned for pressure testing is to be

made out of service for conducting test (Johnson, & Nannay, 2014). All segments

of the ring main line are providing natural gas to different types of consumers. In

case of making out of service for pressure testing would result in energy crisis for

consumers related to the concerned section.

ii. Test pressure: There are three types of pressure tests (API, 2007):

1. Spike test (test pressure to operating pressure ratio is greater than 1.25)

It is used to verify the structural integrity of the pipeline with time

dependant anomalies.

2. Strength test (test pressure to operating pressure ratio is 1.25)

It is used for establishing operating pressure limit.

3. Leak test (test pressure to operating pressure ratio is less than 1.25)

It is used for existence of leak.

At present, the ring main line is operating at 280-300 psi.

Lets assume the test to operating pressure ratio is 1.25.

For operating pressure 280 psi,

Test pressure = 280 1.25 = 350 psi

For operating pressure 300 psi,

Test pressure = 300 1.25 = 375 psi

39

It is clear that, the test pressure is to be maintained at or above the design pressure

of the ring main for the prescribed time period as specified by standards. It itself is a

limiting factor for adopting pressure test for integrity assessment of the ring main line.

As there is no previous integrity assessment for the ring main line, the number

and dimension of flaws within the pipeline are unknown. Adoption of higher test pressure

may result in flaw growth at critical points or failure/rupture results.

On the other side, adopting lower test to operating pressure ratio will reduce the

confidence level and thereby reducing the retest interval. Cost involvement would also be

significant.

iii. Time requirement: Comparing to intelligent pigging, pressure test will require

longer time for each segment of the ring main depending on everything being ok.

First of all, the segment under test will have to be taken out of service. Then it is

to be filled with test water. After filling, the temperature will have to be stable.

Inappropriate test pressure may result in leakages which required the anomalies to

be identified and repaired before next attempt of pressure test or placing the

segment in service.

Safety issues. In appropriate adoption of test pressure might result in failures at

described significant portions of the ring main. Improper/inefficient outage management

would result huge physical and financial losses. Soil erosion would occur in steep

portions on ROW (JACOBS Consultancy, 2013).

Environmental issues. In case of failure during test would cause emission of

pipeline contaminant posing environmental threat. As the condition of the line has not

been assessed so far, identification of failure locations is critical.

40

Direct assessment. Direct assessment is an established method for integrity

assessment of pipelines. But for the ring main line, its adoption as an integrity assessment

tool is limited by its nature.

Physical issues. Only selected portions of the ring main is to be assessed directly

other than the entire pipeline.

Operational issues. The concerned segment to be assessed need not be taken out

of service or subjected to flow curtailment.

Applicability. The nature/procedure of direct assessment technique limits it

applicability to use as integrity assessment tool for the ring main at least for the first time.

This tool only identifies the corrosion threats at the selected locations. Even there are

possibilities that some defects would be left unidentified.

41

3.2 Economic feasibility of intelligent pigging for the ring main

Integrity assessment by an MFL technology based ILI program would play a vital

role to decide whether the rehabilitation measure for entire or portion of the ring main

line is urgent or not. Moreover, the results/findings from the ILI program would act a

baseline survey for future integrity assessment projects for the line.

To make an economic feasibility study of the ILI program for the ring main

transmission line of KGDCL, quotations regarding MFL technology based tool run were

requested to world renowned ILI service providers. Amongst those only one service

provider communicated positively. Several correspondence were done with the company

for providing information of the ring main and receiving the information of

corresponding tool description and financial implications. The correspondence

documents are placed in Appendix D.

3.2.1 Cost of MFL based metal loss run. The service provider intends to visit

the related site of the ring main pipeline route for technical evaluation and finally provide

a detailed proposal for the ILI program. The inspection/ site visit program will be done by

their engineer by a two day tour and it will cost a lump sum amount of € 12,000.

Additional stay will cost of € 1200/ day. The mentioned price include visa arrangement,

flight and travel to/from the company to Chattogram, lodging and messing. They

informed that in case of awarding the project within 6 months after the proposal, 100 %

of cost for site visit will be deducted from the project price. But the quoted price is

excluding taxes and fees applicable in Bangladesh (3p Services, personal communication,

November 17, 2018).

42

A rough amount of 450000-600000 € will be required for MFL tool run. This

amount includes project preparation, the equipment and team and final reporting. In case

of gauge tool run, additional cost will be required (3p Services, personal communication,

November 22, 2018). But head by head estimate cannot be found.

However, the rough price obtained from a renowned ILI service provider can be

taken as a tool for a qualitative indication of economic feasibility of ILI tool run for the

ring main of KGDCL.

Assuming, 1€ = Tk. 94.17

(Euro to taka conversion rate, website information, April 24, 2019.Retrieved from

https://www.exchangerates.org.uk/EUR-BDT-exchangeratehistory.html)

Hence, considering the highest step,

600000 € = 94.17 600000 = Tk.5,65,02,000.00

3.2.2 Cost of standard pig launcher and receiver. Before performing ILI,

standard pig launcher and receiver would have to be installed. The launcher and receiver

diameter would be larger than that of concerned segment of the ring main for ease of

handling ILI tool. Therefore, for 24 inch segment, 36 inch diameter launcher and

receiver costs are considered. Accordingly, 30 inch dia facilities are considered for 20

inch segment and 24 inch dia facilities are considered for 16 inch segment. Rates

proposed by Petrobangla are consulted and yearly 10% increase in rate is assumed.

Segment wise cost involvements for installation of pig launcher and receiver are shown

in Table 3.8.

https://www.exchangerates.org.uk/EUR-BDT-exchangeratehistory.html

43

Table 3.8

Pig launcher and receiver cost

Sl Segment name Cost (Tk)

1 CGS Fouzdarhat to Patenga manifold station

(914 mm OD Pig Launcher and receiver)

61,80,493.00

2 Patenga to Shah Mirpur manifold station


37,45,753.00

3 Shah Mirpur to BFIDC manifold station


56,18,630.00

4 BFIDC manifold station to CGS Fouzdarhat


61,80,493.00

Total 2,17,25,370.00

In words: Taka Two Crore Seventeen Lac Twenty Five Thousand Three

Hundred and Seventy only.

Cost break ups for pig launcher and receiver are placed in Appendix E.

3.2.3 Cost of cleaning run. The price of cleaning pigging of July 2018 was Tk.

2,00,00,000.00 (Taka Two Crore only) (KGDCL, personal communication, July, 2018).

Assuming 10% increase, the price for a single cleaning run on year 2019 would be as

follows:

Cost of cleaning pigging (single run) = 20000000 + (20000000 10%)

= Tk. 2,20,00,000.00

44

3.2.4 Per meter based cost calculation. For performing MFL based ILI in the

ring main summing up the cost of ILI run, installation of standard pig launcher and

receiver and a single cleaning pigging run, the total cost would be as follows :

Total cost = 56502000+ 21725370 + 22000000 = Tk. 10,02,27,370.00

Per meter cost =

Tk./meter

Per meter cost = 1755.30 Tk./meter

VAT @ 5.5% = 1755.30 5.5% = Tk. 96.54

IT@ 5.0% =1755.30 5.0% = Tk. 87.77

Hence,

Cost of MFL based ILI program/per meter including VAT and IT

= 1755.30 + 96.54 + 87.77 = Tk. 1939.61

cost of MFL based ILI program/per meter including VAT and IT = Tk. 1939.61

3.2.5 Rehabilitation cost of the ring main (provisional). Cost required for

rehabilitating the ring main line is estimated in a near to real simplified quantitative

approach by consulting the schedule of rates for construction of high pressure distribution

and transmission line published by the Petrobangla on 2015. Yearly flat 10% increase in

the rates is assumed in the calculation. For materials price, rates are collected from the

bid documents of network upgradation project of KGDCL (KGDCL, personal

communication, May, 2019). Segment wise applicable construction head and cost basis

(including supervisory over head @ 2.5%, contractors profit @ 10%, VAT @ 5.5%, IT

@ 5.0%) are used to obtain total segment construction cost summary. Segment wise cost

of rehabilitation (materials cost and construction cost) with applicable heads are placed in

45

Appendix F and Appendix G respectively. It is to be mentioned that the calculations done

are provisional and simplified for the purpose of the ILI project feasibility study.

Summary of segment wise costs of rehabilitation (cost of materials and cost of

construction) required for the ring main transmission line are placed in Table 3.9.

Table 3.9

Segment wise costs of rehabilitation (cost of materials and cost of construction) required

for the ring main transmission line

Sl

no.

Segment name Length

Km

Cost of

materials

Tk

Cost of

construction

Tk

Total (D+E)

Tk

A B C D E F


Patenga manifold station

19.94 48,32,68,587.00 30,47,35,566.00 78,80,04,153.00


manifold station

5.07 3,46,09,447.00 34,97,63,112.00 38,43,72,559.00


manifold station

19.28 35,34,44,926.00 54,96,21,081.00 90,30,66,008.00

4. BFIDC manifold station

to CGS Fouzdarhat

12.81 31,96,02,602.00 20,33,38,864.00

52,29,41,466.00

Total 57.1 119,09,25,562.00 140,74,58,624.00 259,83,84,186.00

In words: Taka Two Hundred Fifty Nine Crore Eighty Three Lac Eighty Four

Thousand One Hundred and Eighty Six Only.

N.B.: 10% increases in the cost of construction are assumed.

46

For CGS Fouzdarhat to Patenga manifold station segment (segment 1),

Cost of rehabilitation required per meter =

= 39,518.76 Tk/meter

Segment wise costs of rehabilitation required per meter are shown in Table 3.10.

Table 3.10

Segment wise costs of rehabilitation required per meter for the ring main line

Sl no. Segment name Length

Km

Dia

inch

Cost

Tk/meter


Patenga manifold station

19.94 24 39,518.76


manifold station

5.07 16 75,813.13


manifold station

19.28 20 46,839.52

4. BFIDC manifold station to

CGS Fouzdarhat

12.81 24 40,822.91

47

Assuming 10% flat price escalation, segment wise per meter based costs of

rehabilitation forecasts for the next five years (up to 2024) are calculated by excel spread

sheet and placed in Table 3.11.

Table 3.11

Segment wise per meter based costs of rehabilitation forecasts up to the year 2024

Sl

no.

Segment name Cost@2020

Tk/meter

Cost@2021

Tk/meter

Cost@2022

Tk/meter

Cost@2023

Tk/meter

Cost@2024

Tk/meter

1. Segment 1 43,470.64 47,817.70 52,599.47 57,859.42 63,645.36

2. Segment 2 83,394.44 91,733.89 1,00,907.28 1,10,998.00 1,22,097.80

3. Segment 3 51,523.47 56,675.82 62,343.40 68,577.74 75,435.52

4. Segment 4 44,905.20 49,395.72 54,335.29 59,768.82 65,745.70

3.2.6 Findings/observations from the cost analysis. The findings are as follows:

Cost of MFL based ILI program = Tk 1939.61/meter (including VAT and IT)

MFL technology based ILI/intelligent pigging program would play a vital role for

taking appropriate decision regarding huge amount of investment required for

rehabilitating the entire or portion of the ring main line.

48

3.3 Risk analysis

A successful ILI operation requires effective management of risks (Pipeline

Operators Forum, 2012). Risks are needed to be clearly identified at an early stage in the

ILI process. Appropriate selection of the supplier and the tool used for the inspection are

considered key steps in the risk mitigation process.

Since the matter of ILI survey is new in our country and tendencies of failure run

is common, risk analysis for the successful ILI survey is a vital point.

Some known causes for failed ILI survey are as follows (Pipeline Operators

Forum, 2012):

1. Speed & pressure related issues

2. Pipeline related damage

3. Bend configurations

4. Wall thickness changes

5. Line debris

6. Pipeline bore restriction or openings

7. Tool component failure

8. Inappropriate technology selection

9. Pipeline valve operations

The following risk criteria are considered for risk analysis (Pipeline Operators Forum,

2012):

1. Available historical data ( pipeline design & construction process, information

from previous cleaning runs, history of known pipeline defects)

2. Pipeline geographical location

49

3. Access to launching/receiving stations and along length of pipeline for marking &

tracking

4. Operating condition

5. Product (natural gas) composition

3.3.1 Risk identification. Tools and techniques for identifying risks and

opportunities include expert judgment, brainstorming, checklists, SWOT analysis, data

analysis tools (Steyn, 2018). For conducting intelligent pigging of KGDCL ring main

transmission line, data gathering, educated guess and site visit reveals several potential

risks. These are as follows:

1. Tool failure (mechanical)

2. Tool failure (electronic)

3. Tool stuck.

Each issue may arise as a consequence of separate events or in combination.

Again, issues mentioned might occur simultaneously. In this project, individual

contribution of the possible events causing a single risk issue and occurrence of a single

issue at a time is assumed.

3.3.2 Risk plot. Risk is the product of probability of an event to occur and its

associated consequence. For the project purpose, a simplified risk plot which eventually

would be presented as a matrix (risk matrix) in section 3.3.4 consisting of two axes with

probability (P) of an event to occur in y-axis and associated consequence (C) in x-axis is

considered (see Figure 3.1). Each axis is assumed to have a maximum limit of 5 with five

equal steps. Each step of the axes mentioned is provided with perceptive, distinguishable

and gradual qualitative attributes so that the criticality of the probability of an event

50

generating the risk issue and its associated consequence can be comprehensible. The

entire plot is arbitrarily segregated into three regions indicating three distinguished risk

levels namely low, medium and high risks. The ranges of associated risk scores of each

risk level are mentioned in Figure 3.2.

Risk score = P C

Prob

abili

ty (

P)

Frequent 5 5 10 15 20 25

Likely 4 4 8 12 16 20

Possible 3 3 6 9 12 15

Unlikely 2 2 4 6 8 10

Rare 1 1 2 3 4 5

1 2 3 4 5

Significant

Minor

Moderate

Major

Catastrophic

Consequence (C)

Figure 3.2. Risk plot with indication of different risk levels and risk scores

where

: Low risk (1-4)

: Medium risk (5-12)

: High risk (15-25)

51

3.3.3 Risk register. A risk register is prepared in the form of a table showing

possible events for a single risk issue (Table 3.12). Each of the events is scored basing on

the description of section 3.3.1 and section 3.3.2 and the corresponding scores are placed

in the risk score column of the table. Background colors of the risk scores are chosen as

per the risk levels indicated in Figure 3.2.

Table 3.12

Risk register for intelligent pigging of the ring main transmission line of KGDCL

No Risk name Events Probability Consequence Risk

score

1. Tool failure

(mechanical)

1.1 Use of new tools and components Frequent

(5)

Major

(4) 20

1.2 Tool preparation & set up

inconsistency

Possible

(3)

Major

(4)

12

1.3 Tool design change within models Possible

(3)

Major

(4)

12

1.4 Operating conditions out of limit Rare

(1)

Major

(4) 4

1.5 Ineffective Cleaning Unlikely

(2)

Major

(4) 8

1.6 Bore restriction Rare

(1)

Major

(4)

4

(continued)

52

No Risk name Events Probability Consequence Risk

score

2. Tool failure

(electronics)

2.1 Electronic failure (problem with

tool “firmware or software”

Likely

(4)

Major

(4) 16

2.2 Battery Possible

(3)

Major

(4) 12

3. Tool stuck

3.1 Ineffective Cleaning Unlikely

(2)

Major

(4) 8

3.2 Bore restriction Rare

(1)

Moderate

(3) 3

3.3 Unintentional Flow bypassing Possible

(3)

Major

(4) 12

3.4 Excessive wear Unlikely

(2)

Major

(4) 8

3.5 Mechanical damage Unlikely

(2)

Major

(4) 8

3.6 Environment (line pressure,

temperature, contents, immersion

time)

Rare

(1)

Major

(4) 4


53

3.3.4 Risk matrix. Total fourteen (14) risk events with six different scores are

listed in Table 3.12. Eleven events having similar scores are congregated in three

different sets and the rest three events have three different scores. As assumed in Figure

3.2, two of these events fall within the high risk area, eight events fall within the medium

risk area and four events fall within the low risk area of the risk matrix.

Risk score = P C

Prob

abili

ty (

P)

Frequent 5 20

Likely 4 16

Possible 3 12

Unlikely 2 8

Rare 1 3 4

1 2 3 4 5

Significant

Minor

Moderate

Major

Catastrophic

Consequence (C)

Figure 3.3. Risk matrix with risks qualitatively assessed and mapped for

intelligent pigging of the ring main line.

1.1

2.1

1.2, 1.3,

2.2, 3.3

1.5, 3.1,

3.4, 3.5

1.4, 1.6,

3.6

3.2

54

Figure 3.3 illustrates the risk matrix formed by the values of risk score

column of Table 3.12. All the events are denoted by their serial no. of Table 3.12 and

placed in six risk level based squares on the right side of Figure 3.3. The relative

positions of each square on the risk matrix are indicated by arrow marks (Zaman,

Priyanta, & Trisilo, 2017).

3.3.5 Findings from risk analysis. Table 3.13 is showing the contribution of risk

levels of the events considered for risk analysis on intelligent pigging of the ring main

line.

Table 3.13

Percentage of risk level as per the risk matrix

Sl no. Risk level No. of events Percentage of

risk level

1 Low risk 4 28.57 %

2 Medium risk 8 57.14 %

3 High risk 2 14.29 %

Total 14 100 %

It is clear from Table 3.13 that percentage of high risk events is reasonably lower.

Low risk events are insignificant. But percentage of events fall within the medium risk

area is higher. Therefore, the intelligent pigging program for the ring main line primarily

can be considered as a medium risk project. However, appropriate mitigation measures

during planning and execution phase will allow a successful intelligent pigging of the

ring main line.

55

CHAPTER 4: RESULTS AND DISCUSSIONS

There are three river crossings, four railway crossings and three highway

crossings along the route of the ring main line. The Chattogram export processing zone

(CEPZ) area on its way of expansion has already crossed the ring main line. One

manifold station (BFIDC) is situated at the Kalurghat heavy industrial area. Some

industries are set up close to Moizzartek area where the ring main line passes. Figure 2.4

– Figure 2.10 describe these significant portions of the ring main line. Any gas line

failure in these portions of the ring main line may result in catastrophic consequence

related to life and property. An immediate and appropriate integrity assessment of the

entire transmission line will certainly allow adoption of necessary preventive measures.

According to PHMSA, there are four integrity assessment techniques available for

assessing the integrity of natural gas transmission line. These are ILI/ intelligent pigging,

pressure testing, direct assessment and other technologies. Pressure testing requires the

line to be taken out of service during the test period. As there is no previous integrity

assessment of the ring main line, adoption of appropriate test pressure is a great

challenge. A higher test pressure may cause failures at weakened/thinner portions (which

are unknown today) of the line. Failures in river crossings would cause the portion of the

ring main to abandon for further service. Failures in significant areas may cause severe

consequences related to life and properties. On the other hand, adoption of lower test

pressure has the possibility to leave certain classes of flaws being remain undetected.

Moreover, management regarding the test water (storage, treatment, dispose) is a difficult

and cumbersome issue. Amount of test water requirement are equivalent to big ponds

56

(see Table 3.7). Direct assessment has limitation inherent to its definition. It deals with

inspection of pre-selected portions of a transmission line. Again, because of absence of

any previous integrity assessment history of the ring main line, this method is not

considered at least for the first time. Lack of sufficient established guide lines and

information, the fourth method listed by PHMSA is not also considered appropriate for

assessing the integrity of the ring main.

As compared to the all available integrity assessment techniques, intelligent

pigging is seems to be the only applicable method, at least for the first time. The physical

and operational issues are eligible for conducting intelligent pigging. But before

intelligent pigging, standard pig launchers and receivers are needed to be installed prior.

The associated installation cost is Tk 2,17,25,370.00 (Two Crore Seventeen Lac Twenty

Five Thousand Three Hundred and Seventy only). The concerned section is not to be

taken out of service during intelligent pigging. Once the integrity is assessed by

ILI/intelligent pigging for the first time, it will serve as a base line for future survey and

would help to established appropriate inspection interval.

Since its commissioning, the ring main line has reached 35 (thirty five) years of

operation. It is a matter of great concern that no integrity assessment has not done on it

within this large span of service life. Intervals of cleaning type pigging operations are

astonishingly irregular. However, sludge analyses of these operations indicate presence of

metal loss phenomenon within the ring main line. Immediate adoption of MFL

technology based metal loss ILI/intelligent pigging as an integrity assessment tool would

57

provide necessary information of the ring main line. The findings from the ILI program

would help to decide whether any rehabilitation is required for the entire or portion of the

line. Degree of urgency of any measurement issue could also be specified.

Taking the base of information provided by a world renowned ILI service

provider, economic implications of an MFL based metal loss ILI program is calculated

per meter basis.

From the calculation done,

Cost of MFL based metal loss tool run = Tk 1939.61/meter

(Including VAT and IT)

This cost includes the cost of one cleaning run, installation of standard launcher

and receiver and MFL tool run. However, once installed, cost of launcher and receiver

would not be included in future intelligent pigging program.

Costs of rehabilitation for entire or portion of the ring main line are significantly

huge. MFL technology based metal loss ILI/intelligent pigging program would play a

vital role for taking appropriate decision regarding huge amount of investment required

for rehabilitating the entire or portion of the ring main line.

Fourteen risk events under three headings (namely tool failure (mechanical), tool

failure (electronics) and tool stuck) are considered for analyzing the risk of intelligent

pigging program of the ring main line (see Table 3.12). Two of these events fall within

the high risk area, eight events fall within the medium risk area and four events fall

within the low risk area of the risk matrix (see Figure 3.3).

58

It is clear from Table 3.13 that the contribution of high risk factors is reasonably

lower (14.29%). Low risk issues are insignificant (28.57%). But contribution of issues

fall within the medium risk area is higher (57.14%). Therefore, the intelligent pigging

program for the ring main line primarily can be considered as a medium risk project.

However, appropriate preventive/mitigation measures during planning and execution

phase will allow a successful intelligent pigging of the ring main line.

59

CHAPTER 5: CONCLUSIONS AND RECOMMENDATIONS

The conclusions and recommendations are placed in the following paragraphs in

the light of the entire project work.

5.1 Conclusions

1. Three methods proposed by PHMSA for integrity assessment of pipelines are

reviewed.

2. The ring main line has not undergone any integrity assessment program so far. In

addition, sludge analyses of previous cleaning type pigging indicate metal loss

issue within the ring main line. Therefore, appropriate integrity assessment of the

ring man line is as urgent matter.

3. Pressure test is found inappropriate in terms of some physical, operational, safety

and environmental issues.

4. Direct assessment is inappropriate at least for the first time as it deals with the

pre-selected portion of a pipe line rather than the entire one.

5. Adoption of intelligent pigging for assessing the integrity of the ring main line is

appropriate as compared to the other integrity assessment techniques in terms of

physical and operational issues.

6. Appropriate selection of intelligent pigging service provider and tool to be used

would be vital in mitigating the associated risk of intelligent pigging program of

the ring main line.

60

5.2 Recommendations

1. ILI/ intelligent pigging should be adopted immediately to assess the integrity of

the ring main line.

2. Rehabilitation of the ring main line requires huge amount of investment. The

findings from the ILI program would help to decide whether any rehabilitation is

required for the entire or portion of the line. Degree of urgency of any

measurement issue could also be specified.

3. Standard launching and receiving facilities should be installed at the manifold

stations.

4. Approach roads to the manifold stations should be made accessible for ILI tool

handling vehicles.

5. Capacity building steps (training, workshop and seminar) for personnel regarding

intelligent pigging should adopted.

61

REFERENCES

API. (2007). Pressure Testing of Steel Pipelines for the Transportation of Gas, Petroleum

Gas, Hazardous Liquids, Highly Volatile Liquids or Carbon Dioxide. Retrieved

from: http://webcache.googleusercontent.com/search?q=cache:http://gost-

snip.su/download/api_rp_11102007_pressure_testing_of_steel_pipelines_for_the

API. (2013). In-line Inspection Systems Qualification. Retrieved from

https://www.academia.edu/

38052090/API_STD_1163_2013_2nd_Edition_In_line_Inspection_Systems_Qualif

ication_Standard

Bakhrabad Gas Systems Limited. (1994). On-stream pigging completion report and

recommendations. Cumilla, Bangladesh: Bakhrabad Gas Systems Limited.

Cordell, J., and Vanzant, H. (2003). THE PIPELINE PIGGING HANDBOOK. Houston, TX:

Clarion Technical Publishers and Scientific Surveys Ltd.

JACOBS Consultancy. (2013). Technical, Operational, Practical, and Safety

Considerations of Hydrostatic Pressure Testing Existing Pipelines. Washington,

DC: The INGAA Foundation. Retrieved from

https://www.ingaa.org/File.aspx?id=21159&v=95573337

Johnson, J., & Nannay, S. (2014, September). The Role, Limitations, and Value of

Hydrotesting vs In-Line Inspection in Pipeline Integrity Management. Paper

presented at the 2014 10th International Pipeline Conference, Calgary, Alberta,

Canada. doi: 10.1115/IPC2014-33450

http://webcache.googleusercontent.com/search?q=cache:http://gost-snip.su/download/api_rp_11102007_pressure_testing_of_steel_pipelines_for_the

http://webcache.googleusercontent.com/search?q=cache:http://gost-snip.su/download/api_rp_11102007_pressure_testing_of_steel_pipelines_for_the

https://www.academia.edu/%2038052090/API_STD_1163_2013_2nd_Edition_In_line_Inspection_Systems_Qualification_Standard



https://www.ingaa.org/File.aspx?id=21159&v=95573337

62

Kiefner, J. F., & Maxey, W. A. (2013). THE BENEFITS AND LIMITATIONS OF

HYDROSTATIC TESTING. Retrieved from Parliamentary Commission of Quebec

website: http://www.assnat.qc.ca/en/recherche/recherche-avancee.html

Libra Enterprise. (2018). Onstream cleaning pigging of 24-inch, 20-inch & 16-inch 57-km

Chittagong ring main high pressure natural gas pipeline. Chattogram, Bangladesh:

Author.

NACE International. (2010). In-Line Inspection of Pipelines. Retrieved from

https://usdocument.net/ everything-is-okay.html? utm_source=nace-sp0102-2010-pdf

National Transportation Safety Board. (2015). Integrity Management of Gas Transmission

Pipelines in High Consequence Areas (NTSB/SS-15/01 PB2015-102735).

Retrieved from https://www.ntsb.gov/safety/safety-studies/Documents/SS1501.pdf

Pipeline Operators Forum. (2012). Guidance on achieving ILI First Run Success. Retrieved

from http://www.pipelineoperators.org

Pipeline Operators Forum. (2016). Specifications and requirements for in-line inspection of

pipelines. Retrieved from http://www.pipelineoperators.org

Steyn, J. (2018, October 1). Introduction to Project Risk Management: Part 2-Identify,

analyse, action and monitor project risks. Retrieved from:

https://www.researchgate.net/publication/327981232_Introduction_to_Project_Risk

_Management_Part_2-Identify_analyse_action_and_monitor_project_risks

T.D. Williamson. (2016). T.D. Williamson 2016 Guide to Pigging. Retrieved from:

https://info.tdwilliamson.com/guidetopigging

http://www.assnat.qc.ca/en/recherche/recherche-avancee.html

https://usdocument.net/%20%20everything-is-okay.html?%20utm_source=nace-sp0102-2010-pdf

https://www.ntsb.gov/safety/safety-studies/Documents/SS1501.pdf

https://www.researchgate.net/publication/327981232_Introduction_to_Project_Risk_Management_Part_2-Identify_analyse_action_and_monitor_project_risks

https://www.researchgate.net/publication/327981232_Introduction_to_Project_Risk_Management_Part_2-Identify_analyse_action_and_monitor_project_risks

63

Wint, D. (2011). Difficult to Pig Pipelines [PowerPoint slides]. Retrieved from

https://www.scribd.com/document/138422032/PM9-Difficult-to-Pig-Pipelines

Zaman, M. B., Priyanta, D., & Trisilo, F. (2017). Risk assessment in financial feasibility of

tanker project using monte carlo simulation. International Journal of Marine

Engineering Innovation and Research, 1(4), 303-316.

https://www.scribd.com/document/138422032/PM9-Difficult-to-Pig-Pipelines

64

Appendix A

List of Valve station along the ring main

Table A.1

List of valve stations along the route of the ring main

Sl no. Name of valve station Address

01 DLVE-2 Dhaka-Chattogram rail crossing, solimpur, Chattogram.

02 DLVE-3 Nazirhat rail crossing (near Nasirabad HP-DRS),

Cantonment, Chattogram.

03 DLVE-4 Nazirhat rail crossing, Mir para, Oxygen, Chattogram

04 DLVE-5 Dohazari rail crossing, Tek para, C&B,

Kalurghat, Chattogroam

05 DLVE-6 Dohazari rail crossing, Tek para, C&B,

Kalurghat, Chattogroam

06 DLVE-7 BFIDC manifold station, Kalurghat, Chattogram.

07 DLVE-8 TK Chemical complex, Char Khizirpur, Chattogram

08 DLVS-2 Bandar rail crossing, Salimpur, Chattogram.

(continued)

65

Table A.1 (continued)

Sl no. Name of valve station Address

09 DLVS-3 Choudhury para, North Halishahar, Chattogram.

10 DLVS-4 Narikeltala, South Halishahar, Chattogram.

11 DLVS-5 Patenga manifold station, Chattogram.

12 DLVS-6 KAFCO, Anowara, Chattogram.

13 DLVS-7 Moizzartek, Cox’s Bazar road, Karnaphuli, Chattogram.

14 DLVS-8 Baruapara, Shikobaha, Chattogram.

Note. Information collected from KGDCL Transmission department (KGDCL, personal

communication, November, 2018).

66

Gas withdrawal points

Table A.2

List of HP-DRS along the ring main transmission line

Sl no Name of HP/DRS Location Capacity

(MMSCFD)

Inlet

Pressure

(psig)

Outlet

Pressure

(psig)

1. City Gate HP/DRS Fouzdarhat, Chattogram. 20 350 150

2. CEPZ HP/DRS CEPZ , Chattogram. 20 350 150

3. Kalurghat HP/DRS Chandgao, Chattogram. 25 350 150

4. Nasirabad

HP/DRS

Cantonment, Baizid

bostami, Chattogram.

35 350 150

5. Halishahar

HP/DRS

Halishahar, Chattogram. 30 350 150

6. Char Khidirpur

HP/DRS

Boalkhali, Chattogram.. 07 350 58

9. Patenga HP/DRS 15 no. Ghat, Adjacent to

Air port, Chattogram..

08 350 58

10. Char Pathar

Ghhata (Old)

HP/DRS

Adjacent to S.Alam

Mills, Moizzar Tek,

Chattogram..

07 350 60

(continued)

67

Table A.2 (continued)

Sl no Name of HP/DRS Location Capacity

(MMSCFD)

Inlet

Pressure

(psig)

Outlet

Pressure

(psig)

11. Char Pathar

Ghhata (New)

HP/DRS

Adjacent to S.Alam

Mills, Cox’s Bazar Road,

Chattogram..

30 350 150

14. CUFL HP/DRS Anowara, Chattogram. 02 350 60

15. Kalar Pool

HP/DRS

Shikalbaha, patiya,

Chattogram.

30 350 150

16. United Power

HP/DRS

Adjacent CEPZ Mazjid,

Chattogram.

20 350 150

Note. Information collected from KGDCL Transmission department (KGDCL, personal

communication, November, 2018).

68

Appendix B

Spread sheet calculation for gas flow range and travel time within speed limit

Segment 1: CGS to Patenga manifold

Table B.1

Operating pressure 350 psi, gas flow rate: 19-70 MMSCFD

Flow rate,Q

(MMSCFD)

Base

pressure,

Pb

(psi)

Operating

Pressure,

P

(psi)

Super

compressibility

factor @ 60 0F,

Fpv

Internal

diameter, d

(inch)

Tool

Speed,

VILI

(mph)

Travel

time

(hr)

19 14.69 350 1.028525 23.656 1.95 6.39

19.5 14.69 350 1.028525 23.656 2.00 6.23

25 14.69 350 1.028525 23.656 2.56 4.86

30 14.69 350 1.028525 23.656 3.08 4.05

35 14.69 350 1.028525 23.656 3.59 3.47

40 14.69 350 1.028525 23.656 4.10 3.04

45 14.69 350 1.028525 23.656 4.62 2.70

50 14.69 350 1.028525 23.656 5.13 2.43

55 14.69 350 1.028525 23.656 5.64 2.21

60 14.69 350 1.028525 23.656 6.16 2.02

65 14.69 350 1.028525 23.656 6.67 1.87

68.2 14.69 350 1.028525 23.656 7.00 1.78

70 14.69 350 1.028525 23.656 7.18 1.74

69

Table B.2


Flow rate,Q

(MMSCFD)

Base

pressure,

Pb

(psi)

Operating

Pressure,

P

(psi)

Super

compressibility

factor @ 60 0F,

Fpv

Internal

diameter, d

(inch)

Tool Speed,

VILI

(mph)

Travel

time

(hr)

15 14.69 300 1.02435 23.656 1.81 6.89

16.55 14.69 300 1.02435 23.656 2.00 6.24

20 14.69 300 1.02435 23.656 2.41 5.16

25 14.69 300 1.02435 23.656 3.02 4.13

30 14.69 300 1.02435 23.656 3.62 3.44

35 14.69 300 1.02435 23.656 4.22 2.95

40 14.69 300 1.02435 23.656 4.83 2.58

45 14.69 300 1.02435 23.656 5.43 2.30

50 14.69 300 1.02435 23.656 6.03 2.07

55 14.69 300 1.02435 23.656 6.64 1.88

58 14.69 300 1.02435 23.656 7.00 1.78

60 14.69 300 1.02435 23.656 7.24 1.72

70

Table B.3


Flow rate,Q

(MMSCFD)

Base

pressure,

Pb

(psi)

Operating

Pressure,

P

(psi)

Super

compressibility

factor @ 60 0F,

Fpv

Internal

diameter, d

(inch)

Tool

Speed,

VILI

(mph)

Travel

time

(hr)

14 14.69 275 1.0222625 23.656 1.85 6.73

15 14.69 275 1.0222625 23.656 1.98 6.29

15.1 14.69 275 1.0222625 23.656 2.00 6.24

17 14.69 275 1.0222625 23.656 2.25 5.55

20 14.69 275 1.0222625 23.656 2.64 4.71

25 14.69 275 1.0222625 23.656 3.30 3.77

30 14.69 275 1.0222625 23.656 3.97 3.14

35 14.69 275 1.0222625 23.656 4.63 2.69

40 14.69 275 1.0222625 23.656 5.29 2.36

45 14.69 275 1.0222625 23.656 5.95 2.10

50 14.69 275 1.0222625 23.656 6.61 1.89

52.95 14.69 275 1.0222625 23.656 7.00 1.78

53 14.69 275 1.0222625 23.656 7.01 1.78

71

Table B.4


Flow rate,Q

(MMSCFD)

Base

pressure,

Pb

(psi)

Operating

Pressure,

P

(psi)

Super

compressibility

factor @ 60 0F,

Fpv

Internal

diameter, d

(inch)

Tool

Speed,

VILI

(mph)

Travel

time

(hr)

13 14.69 250 1.020175 23.656 1.90 6.57

13.7 14.69 250 1.020175 23.656 2.00 6.23

15 14.69 250 1.020175 23.656 2.19 5.69

17 14.69 250 1.020175 23.656 2.48 5.02

20 14.69 250 1.020175 23.656 2.92 4.27

25 14.69 250 1.020175 23.656 3.65 3.41

30 14.69 250 1.020175 23.656 4.38 2.85

35 14.69 250 1.020175 23.656 5.11 2.44

40 14.69 250 1.020175 23.656 5.84 2.13

45 14.69 250 1.020175 23.656 6.57 1.90

47.95 14.69 250 1.020175 23.656 7.00 1.78

48 14.69 250 1.020175 23.656 7.01 1.78

72

Segment 2: Patenga to Shah Mirpur manifold

Table B.5


Flow rate,Q

(MMSCFD)

Base

pressure,

Pb

(psi)

Operating

Pressure,

P

(psi)

Super

compressibility

factor @ 60 0F,

Fpv

Internal

diameter, d

(inch)

Tool

Speed,

VILI

(mph)

Travel

time

(hr)

8 14.69 350 1.028525 15.750 1.85 1.71

8.65 14.69 350 1.028525 15.750 2.00 1.58

10 14.69 350 1.028525 15.750 2.31 1.37

15 14.69 350 1.028525 15.750 3.47 0.91

20 14.69 350 1.028525 15.750 4.63 0.68

25 14.69 350 1.028525 15.750 5.79 0.55

30 14.69 350 1.028525 15.750 6.94 0.46

30.25 14.69 350 1.028525 15.750 7.00 0.45

31 14.69 350 1.028525 15.750 7.17 0.44

73

Table B.6


Flow rate,Q

(MMSCFD)

Base

pressure,

Pb

(psi)

Operating

Pressure,

P

(psi)

Super

compressibility

factor @ 60 0F,

Fpv

Internal

diameter,

d

(inch)

Tool

Speed,

VILI

(mph)

Travel

time

(hr)

7 14.69 300 1.02435 15.750 1.91 1.66

7.35 14.69 300 1.02435 15.750 2.00 1.58

10 14.69 300 1.02435 15.750 2.72 1.16

15 14.69 300 1.02435 15.750 4.08 0.78

20 14.69 300 1.02435 15.750 5.44 0.58

25 14.69 300 1.02435 15.750 6.81 0.47

25.7 14.69 300 1.02435 15.750 7.00 0.45

26 14.69 300 1.02435 15.750 7.08 0.45

74

Table B.7


Flow rate,Q

(MMSCFD)

Base

pressure,

Pb

(psi)

Operating

Pressure, P

(psi)

Super

compressibility

factor @ 60 0F,

Fpv

Internal

diameter,

d

(inch)

Tool

Speed,

VILI

(mph)

Travel

time

(hr)

6 14.69 275 1.0222625 15.750 1.79 1.77

6.7 14.69 275 1.0222625 15.750 2.00 1.59

10 14.69 275 1.0222625 15.750 2.98 1.06

15 14.69 275 1.0222625 15.750 4.47 0.71

20 14.69 275 1.0222625 15.750 5.96 0.53

22 14.69 275 1.0222625 15.750 6.56 0.48

23 14.69 275 1.0222625 15.750 6.86 0.46

23.46 14.69 275 1.0222625 15.750 7.00 0.45

24 14.69 275 1.0222625 15.750 7.16 0.44

75

Table B.8


Flow rate,Q

(MMSCFD)

Base

pressure,

Pb

(psi)

Operating

Pressure, P

(psi)

Super

compressibility

factor @ 60 0F,

Fpv

Internal

diameter, d

(inch)

Tool

Speed,

VILI

(mph)

Travel

time

(hr)

6 14.69 250 1.020175 15.750 1.98 1.60

6.06 14.69 250 1.020175 15.750 2.00 1.59

10 14.69 250 1.020175 15.750 3.29 0.96

15 14.69 250 1.020175 15.750 4.94 0.64

20 14.69 250 1.020175 15.750 6.59 0.48

21.25 14.69 250 1.020175 15.750 7.00 0.45

22 14.69 250 1.020175 15.750 7.25 0.44

76

Segment 3: Shah Mirpur to BFIDC manifold

Table B.9


Flow rate,Q

(MMSCFD)

Base

pressure,

Pb

(psi)

Operating

Pressure,

P

(psi)

Super

compressibility

factor @ 60 0F,

Fpv

Internal

diameter, d

(inch)

Tool

Speed,

VILI

(mph)

Travel

time

(hr)

10 14.69 350 1.028525 19.688 1.48 8.14

13.5 14.69 350 1.028525 19.688 2.00 6.03

15 14.69 350 1.028525 19.688 2.22 5.42

20 14.69 350 1.028525 19.688 2.96 4.07

25 14.69 350 1.028525 19.688 3.70 3.25

30 14.69 350 1.028525 19.688 4.44 2.71

35 14.69 350 1.028525 19.688 5.18 2.32

40 14.69 350 1.028525 19.688 5.92 2.03

45 14.69 350 1.028525 19.688 6.67 1.81

47.25 14.69 350 1.028525 19.688 7.00 1.72

48 14.69 350 1.028525 19.688 7.11 1.69

77

Table B.10


Flow rate,Q

(MMSCFD)

Base

pressure,

Pb

(psi)

Operating

Pressure,

P

(psi)

Super

compressibility

factor @ 60 0F,

Fpv

Internal

diameter, d

(inch)

Tool

Speed,

VILI

(mph)

Travel

time

(hr)

10 14.69 300 1.02435 19.688 1.74 6.92

11.5 14.69 300 1.02435 19.688 2.00 6.01

15 14.69 300 1.02435 19.688 2.61 4.61

20 14.69 300 1.02435 19.688 3.48 3.46

25 14.69 300 1.02435 19.688 4.36 2.77

30 14.69 300 1.02435 19.688 5.23 2.31

35 14.69 300 1.02435 19.688 6.10 1.98

40 14.69 300 1.02435 19.688 6.97 1.73

40.2 14.69 300 1.02435 19.688 7.00 1.72

41 14.69 300 1.02435 19.688 7.14 1.69

78

Table B.11


Flow rate,Q

(MMSCFD)

Base

pressure,

Pb

(psi)

Operating

Pressure,

P

(psi)

Super

compressibility

factor @ 60 0F,

Fpv

Internal

diameter, d

(inch)

Tool

Speed,

VILI

(mph)

Travel

time

(hr)

10 14.69 275 1.0222625 19.688 1.91 6.31

10.5 14.69 275 1.0222625 19.688 2.00 6.01

15 14.69 275 1.0222625 19.688 2.86 4.21

20 14.69 275 1.0222625 19.688 3.82 3.16

25 14.69 275 1.0222625 19.688 4.77 2.53

30 14.69 275 1.0222625 19.688 5.72 2.10

35 14.69 275 1.0222625 19.688 6.68 1.80

36.7 14.69 275 1.0222625 19.688 7.00 1.72

37 14.69 275 1.0222625 19.688 7.06 1.71

79

Table B.12


Flow rate,Q

(MMSCFD)

Base

pressure,

Pb

(psi)

Operating

Pressure,

P

(psi)

Super

compressibility

factor @ 60 0F,

Fpv

Internal

diameter, d

(inch)

Tool

Speed,

VILI

(mph)

Travel

time

(hr)

9 14.69 250 1.020175 19.688 1.90 6.35

9.5 14.69 250 1.020175 19.688 2.00 6.02

10 14.69 250 1.020175 19.688 2.11 5.72

15 14.69 250 1.020175 19.688 3.16 3.81

20 14.69 250 1.020175 19.688 4.22 2.86

25 14.69 250 1.020175 19.688 5.27 2.29

30 14.69 250 1.020175 19.688 6.32 1.91

33.2 14.69 250 1.020175 19.688 7.00 1.72

34 14.69 250 1.020175 19.688 7.17 1.68

80

Segment 4: BFIDC to CGS manifold

Table B.13


Flow rate,Q

(MMSCFD)

Base

pressure,

Pb

(psi)

Operating

Pressure,

P

(psi)

Super

compressibility

factor @ 60 0F,

Fpv

Internal

diameter, d

(inch)

Tool

Speed,

VILI

(mph)

Travel

time

(hr)

19 14.69 350 1.028525 23.656 1.95 4.11

19.5 14.69 350 1.028525 23.656 2.00 4.00

25 14.69 350 1.028525 23.656 2.56 3.12

30 14.69 350 1.028525 23.656 3.08 2.60

35 14.69 350 1.028525 23.656 3.59 2.23

40 14.69 350 1.028525 23.656 4.10 1.95

45 14.69 350 1.028525 23.656 4.62 1.73

50 14.69 350 1.028525 23.656 5.13 1.56

55 14.69 350 1.028525 23.656 5.64 1.42

60 14.69 350 1.028525 23.656 6.16 1.30

65 14.69 350 1.028525 23.656 6.67 1.20

68.2 14.69 350 1.028525 23.656 7.00 1.14

70 14.69 350 1.028525 23.656 7.18 1.11

81

Table B.14


Flow rate,Q

(MMSCFD)

Base

pressure,

Pb

(psi)

Operating

Pressure,

P

(psi)

Super

compressibility

factor @ 60 0F,

Fpv

Internal

diameter, d

(inch)

Tool

Speed,

VILI

(mph)

Travel

time

(hr)

15 14.69 300 1.02435 23.656 1.81 4.42

16.55 14.69 300 1.02435 23.656 2.00 4.01

20 14.69 300 1.02435 23.656 2.41 3.32

25 14.69 300 1.02435 23.656 3.02 2.65

30 14.69 300 1.02435 23.656 3.62 2.21

35 14.69 300 1.02435 23.656 4.22 1.90

40 14.69 300 1.02435 23.656 4.83 1.66

45 14.69 300 1.02435 23.656 5.43 1.47

50 14.69 300 1.02435 23.656 6.03 1.33

55 14.69 300 1.02435 23.656 6.64 1.21

58 14.69 300 1.02435 23.656 7.00 1.14

60 14.69 300 1.02435 23.656 7.24 1.11

82

Table B.15


Flow rate,Q

(MMSCFD)

Base

pressure,

Pb

(psi)

Operating

Pressure,

P

(psi)

Super

compressibility

factor @ 60 0F,

Fpv

Internal

diameter, d

(inch)

Tool

Speed,

VILI

(mph)

Travel

time

(hr)

14 14.69 275 1.0222625 23.656 1.85 4.33

15 14.69 275 1.0222625 23.656 1.98 4.04

15.1 14.69 275 1.0222625 23.656 2.00 4.01

17 14.69 275 1.0222625 23.656 2.25 3.56

20 14.69 275 1.0222625 23.656 2.64 3.03

25 14.69 275 1.0222625 23.656 3.30 2.42

30 14.69 275 1.0222625 23.656 3.97 2.02

35 14.69 275 1.0222625 23.656 4.63 1.73

40 14.69 275 1.0222625 23.656 5.29 1.51

45 14.69 275 1.0222625 23.656 5.95 1.35

50 14.69 275 1.0222625 23.656 6.61 1.21

52.95 14.69 275 1.0222625 23.656 7.00 1.14

53 14.69 275 1.0222625 23.656 7.01 1.14

83

Table B.16


Flow rate,Q

(MMSCFD)

Base

pressure,

Pb

(psi)

Operating

Pressure,

P

(psi)

Super

compressibility

factor @ 60 0F,

Fpv

Internal

diameter, d

(inch)

Tool

Speed,

VILI

(mph)

Travel

time

(hr)

13 14.69 250 1.020175 23.656 1.90 4.22

13.7 14.69 250 1.020175 23.656 2.00 4.00

15 14.69 250 1.020175 23.656 2.19 3.66

17 14.69 250 1.020175 23.656 2.48 3.23

20 14.69 250 1.020175 23.656 2.92 2.74

25 14.69 250 1.020175 23.656 3.65 2.19

30 14.69 250 1.020175 23.656 4.38 1.83

35 14.69 250 1.020175 23.656 5.11 1.57

40 14.69 250 1.020175 23.656 5.84 1.37

45 14.69 250 1.020175 23.656 6.57 1.22

47.95 14.69 250 1.020175 23.656 7.00 1.14

48 14.69 250 1.020175 23.656 7.01 1.14

84

Appendix C

Test water quantity calculation

Segment internal volume = π (D-(d 2))/2)2 L ------------------------------------------[C.1]

Where,

π = 3.14

D = Outer diameter of concerned segment

d = wall thickness of the concerned segment

L = Length of the concerned segment

Lets consider segment 1.

Length, L = 19.94 km =

= 65419.95 ft

Outer diameter = 24 inch

Wall thickness, d = 0.344 inch

Inner diameter, ((D-(d 2)) = 24 – (0.344 2) = 23.312 inch

(D-(d 2))/2 =

= 11.656 inch

(D-(d 2))/2)2 = 11.662 = 135.86234 inch2 = 0.94 ft2

Placing the value of length, L and (D-(d 2))/2)2 in equation C.1, we get,

Test water for segment 1 = 3.14 0.94 65419.95 = 193810.11 ft3

1 ft3 = 0.24 bbl

193810.11 ft3 = 0.24 193810.11 = 46514.43 bbl

Similar procedure is followed for other segments.

85

Appendix D

Quotation correspondence with 3P Services

Figure D.1. Quotation related document (3P services, personal communication, November 17, 2018).

86

Figure D.2. Quotation related document (3P services, personal communication,

November 17, 2018).

87


November 17, 2018).

88


November 17, 2018).

89

Appendix E

Cost of Pig launcher and receiver

Segment wise cost of pig launcher & receiver are placed in Table E.1.

Table E.1

Cost of pig launcher and receiver.

Sl Segment name Cost@2015 Cost@2019

1 1st segment (914 mm OD Pig Launcher & receiver)

4221360 6180493

2 2nd segment (610 mm OD Pig Launcher & receiver)

2558400 3745753

3 3rd segment (762 mm OD Pig Launcher & receiver)

3837600 5618630

4 4th segment (914 mm OD Pig Launcher & receiver)

4221360 6180493

Total 14838720 21725370

IN WORDS: TWO CRORE SEVENTEEN LAC TWENTY FIVE THOUSAND THREE HUNDRED & SEVENTY ONLY.

* Rates are inclusives of payable VAT @5.5%, [email protected]%, Sup.OH @2.5%

and contractors profit @10%

** Yearly 10 % price increase assumed.

mailto:Cost@2015

mailto:Cost@2019

90

Appendix F

Segment wise provisional materials requirement for construction of the ring main line

Table F.1

Provisional list of materials required for the construction of 19.94 km 24" 350 psi transmission

line (1st segment)

Sl

no.

Item Unit Unit

Cost

(in Lac

Tk)

Quantity Cost

(Tk)

CD-

VAT

Cost

including

CD-VAT

(Tk)

1 24" API 5L Gr. B Line pipe

(WT 9.53 mm)

km 150.61 19.94 300316340 45% 435458693

2 Coating materials LS 4566260 80% 8219268

3 Valves No. 13.99 3 4197000 35% 5665950

4 Butt weld fittings,

Tee's,Elbows, Flange, Gasket,

Cradle, Gauges, Insulating

joints and other necessary

fittings (5% of Line pipe cost)

LS

15015817 60% 24025307.2

5 CP materials (1.5 % of

Linepipe cost)

LS

4504745 30% 5856168.63

6 TEG No. 28.88 1 2888000 40% 4043200

TOTAL 331488162

483268587

In word : Forty Eight Crore Thirty Two Lac Sixty Eight Thousand Five Hundred & Eighty

Seven only.

91

Table F.2

Provisional list of materials required for the construction of 2.57 km 16" 350 psi transmission

line (2nd segment),excluding river crossing portion

Sl

no.

Item Unit Unit

Cost

(in Lac

Tk)

Quantity Cost

(Tk)

CD-

VAT

Cost

including

CD-VAT

(Tk)

1 16" API 5L X 52 Line pipe

(WT 7.9 mm) Km 68.32 2.57

17558240 45% 25459448


3 Valves No. 8.52 2 1704000 35% 2300400

4 Butt weld fittings, Tee's,

Elbows, Flange, Gasket,




LS

877912 60% 1404659.2


Linepipe cost)

LS

263374 30% 342385.68

6 TEG No. 28.88 1 2888000 40% 4043200

TOTAL 23880056

34609447

In word: Three Crore Forty Six Lac Nine Thousand Four Hundred & Forty Seven only.

92

Table F.3

Provisional list of materials required for the construction of 17.78 km 20" 350 psi

transmission line (3rd segment) excluding river crossing portions

Sl

no.

Item Unit Unit

Cost

(in Lac

Tk)

Quantity Cost

(Tk)

CD-

VAT

Cost

including

CD-VAT

(Tk)

1 20" API 5L X 52 Line pipe

(WT 9.53 mm)3LPE coated

Km 125.11 17.78 222445580 45% 322546091

2 Valves No. 11.66 3 3498000 35% 4722300






LS

11122279 60% 17795646.4


Linepipe cost)

LS

3336684 30% 4337688.81

5 TEG No. 28.88 1 2888000 40% 4043200

TOTAL 243290543

353444926

In word: Thirty Five Crore Thirty Four Lac Forty Four Thousand Nine Hundred & Twenty

Six only.

93

Table F.4

Provisional list of materials required for the construction of 12.81 km 24" 350 psi

transmission line (4th segment)

Sl

no.

Item Unit Unit

Cost

(in Lac

Tk)

Quantity Cost

(Tk)

CD-

VAT

Cost

including

CD-VAT

(Tk)

1 24" API 5L Gr. B Line pipe

(WT 9.53 mm) km 150.61 12.81

192931410 45% 279750544.5


3 Valves No. 13.99 6 8394000 35% 11331900






LS

9646570.5 60% 15434512.8


Linepipe cost)

LS

2893971 30% 3762162.495

6 TEG No. 28.88 1 2888000 40% 4043200

TOTAL 219687442

319602602

In word: Thirty One Crore Ninety Six Lac Two Thousand Six Hundred & Two only.

94

Appendix G

Cost of construction (provisional) of the ring main as per schedule of Petrobangla

Table G.1

Provisional schedule of rates & quantities for construction of 24" 19.94 km 350 psi transmission

line from CGS Fouzdarhat to Patenga Manifold station (1st segment)

Sl no. Description Cost basis Qty. Unit Amount (tk) Remark

1 Preparation of ROW 179580.00

Tk./km

19.94 km 3580825.20

2 Transportations, hauling of pipes

from Company's depot / pipe yard to

construction site.

58.49

Tk./ton-km

3157.80

40

ton

km

7387988.88 Assuming 40

km distance.

3 Transportation and storage of

induction Bends, valves, flanges,

tapes, primer and other pipeline

materials & fittings from company's

depot to work site.

107.26

Tk./ton-km

200

40

ton

km

858080.00 Assuming 40

km distance.

4 Stringing of line pipe along with

Right-of-way (ROW)

290.19

Tk./mtr

19940 mtr 5786388.60

5 Field bends to 8D radius using

Hydraulic Pipe bending machine

3355.17

Tk./mtr

6000 mtr 20131020.00

(continued)

95


6 Welding: cleaning, cutting, beveling

of pipes and fittings including

chamfering of over thickness and re-

beveling (if required) of pipes and

fittings.Line up by internal clamp

and welding and weld repairs as per

API.1104

16096.60

Tk./no

1680 nos. 27042288.00

7 External cleaning of pipe prior to

coating & wrapping operation by

sand blasting.

587.33

Tk./mtr

19940 mtr 11711360.20

8 Applying primer and polyethylene

tape (inner and other tape) by semi

mechanical machine and holyday

checking to the pipe and bends.

1293.55

Tk./mtr

19940 mtr 25793387.00

9 Cleaning of weld area of mainline

pipe by sand blasting and joint

coating by heat shrink sleeve

1230.00

Tk./no

1680 nos. 2066400.00

10 Trenching 610.08

Tk./mtr

19940 mtr 12164995.20

11 Lowering 491.02

Tk./mtr

19940 mtr 9790938.80

Table G.1 (continued)

(continued)

96


12 Back filling with proper compaction

including ditch plugging in hill

section along the slopes as per

company's specification.

309.96

Tk./mtr

19940 mtr 6180602.40

13 Hydro-test 781.05

Tk./mtr

19940 mtr 15574137.00

14 Clean up and re-instatement of

ROW

311.60

Tk./mtr

19940 mtr 6213304.00

15 a) Hook up/Tie-in works at source

manifold/offtake with necessary

piping & other ancilliary works.

LS 369000.00

b) Hook up/Tie in at outlet source

manifold off/take with necessary

piping & other ancilliary works.

LS 369000.00

16 Providing assistance with

commissioning (supply of required

quantity of commissioning pigs and

Nitrogen)

85047.12

Tk./km

19.94 km 1695839.57

17 Cased Road & Rail crossing by

thrust boring as per design

and drawing.

i) Casing pipe: 762 mm OD

12226.20

Tk./mtr

24 mtr 293428.80


(continued)

97


ii) Carrier pipe: 610 mm OD

Rail crossing = 01 no. (12 mtr)

Road Crossing = 01 no.(12 mtr)

18 Fabrication and installation of Pig

launcher, Pig receiver/valve stations

including all sorts of mechanical

erections, civil works, foundation,

fenching, painting as per design &

drawings complete in all respects.

LS 2558400.00 receiver &

launcher

19 Cost of radiography 8153.66

Tk./no

1680 nos. 13698148.80

20 Hot tapping along with piping and

off-take (as necessary to be carried

out by specialized sub-contractor on

turn key EPC contract)

30381000.00

21 Construction and placement of

Marker post including supply of MS

rod, Cement, Sand, Bricks, Chips

etc. & shuttering materials etc.

3198 Tk./no 20 nos. 63960.00

22 Mobilization and demobilization LS 4428000.00

Total 208138492

In words: TWENTY CRORE EIGHTY ONE LAC THIRTY EIGHT THOUSAND FOUR HUNDRED & NINETY TWO ONLY


98

Table G.2


line from Patenga To Shah Mirpur Manifold station (2nd segment)

Sl

no.

Description Cost basis Qty. Unit Amount (tk) Remark


Tk./km

5.07 km 638160.90

2 Transportations, hauling of pipes


construction site.

58.49

Tk./ton-km

321.25

40

ton

km

751596.50 Assuming 40

km distance.





depot to work site.

82.66

Tk./ton-km

15

40

ton

km

49596.00 Assuming 40

km distance.


Right-of-way (ROW)

237.43

Tk./mtr

2570 mtr 610195.10



3019.65

Tk./mtr

250 mtr 754912.50

(continued)

99

Sl

no.






fittings. Line up by internal clamp


API.1104

11808.00

Tk./no

230 nos. 2715840.00



sand blasting.

391.55

Tk./mtr

2570 mtr 1006283.50





1108.76

Tk./mtr

2570 mtr 2849513.20




1002.92

Tk./no

230 nos. 230671.60

10 Trenching 401.80

Tk./mtr

2570 mtr 1032626.00

11 Lowering 409.18

Tk./mtr

2570 mtr 1051592.60


(continued)

100

Sl

no.






206.64

Tk./mtr

2570 mtr 531064.80


Tk./mtr

5070 mtr 2313035.40

14 Clean up and re-instatement of ROW 197.62

Tk./mtr

2570 mtr 507883.40



piping & other ancillary works.

LS 221400.00




LS 221400.00




Nitrogen)

49145.88

Tk./km

5.07 km 249169.61





launcher


(continued)

101

Sl

no.



fencing, painting as per design &



Tk./no

230 nos. 1250227.10





25584000.00

20 Major River Crossing along with

supply of FBE line pipe,isolation

valves, chemicals, consumables, rig,

side Boom etc. as necessary of HDD

method under EPC turn key

contract including OH, VAT, ITand

Contractors profit.

a) Karnaphuli river crossing 2500

mtr

63960000

Tk./

river width

500M -

1000M

2500 mtr 191880000.00




3198 Tk./no 3 nos. 9594.00


(continued)

102

Sl

no.




Total 238892912

In words: TWENTY THREE CRORE EIGHTY EIGHT LAC NINETY TWO THOUSAND NINE HUNDRED & TWELVE ONLY


103

Table G.3

Provisional schedule of rates & quantities for construction of 20 inch 19.28 km 350 psi

transmission line from Shah Mirpur to BFIDC Manifold station (3rd segment)

Sl

no.



Tk./km

19.28 km 3462302.40

2 Transportation, hauling of pipes


construction site.

57.72

Tk./ton-km

2736

40

ton

km

6316876.80 Assuming 40

km distance.





depot to work site.

92.50

Tk./ton-km

200

40

ton

km

740000.00 Assuming 40

km distance.


Right-of-way (ROW)

261.17

Tk./mtr

17280 mtr 4513017.60



3355.17

Tk./mtr

10000 mtr 33551700.00

(continued)

104

Sl

no.








API.1104

14137.62

Tk./no

1460

nos.

20640925.20



sand blasting.

469.86

Tk./mtr

17280 mtr 8119180.80





1194.15

Tk./mtr

17280 mtr 20634912.00




1107.00

Tk./no

1460 nos. 1616220.00

10 Trenching 508.40

Tk./mtr

17280 mtr 8785152.00


(continued)

105

Sl

no.


11 Lowering 409.18

Tk./mtr

17280 mtr 7070630.40





258.30

Tk./mtr

17280 mtr 4463424.00


Tk./mtr

19280 mtr 10861195.20


Tk./mtr

17280 mtr 4405363.20




LS 295200.00




LS 295200.00




Nitrogen)

55886.28

Tk./km

19.28 km 1077487.48


(continued)

106

Sl

no.




and drawing.



Ctg-Cox's Bazar highway crossing

10188.50

Tk./mtr

20 mtr 203770.00








launcher


Tk./no

1460 nos. 9920276.60





25830000.00

21 Major River Crossing along with

supply of FBE line pipe, Isolation

valves, Chemicals, Consumables,

65559000

Tk./

river width


(continued)

107

Sl

no.


Rig, Side Boom etc.As necessary of

HDD method under EPC turn key

contract

500 M -

1000M

a) Kalarpul crossing (500 mtr) 65559000.00

b)Kalurghat Karnaphuli crossing

(1500 mtr)

131118000.00





3198 Tk./no 20 nos. 63960.00


Total 375398594

In words: THIRTY SEVEN CRORE FIFTY THREE LAC NINETY EIGHT THOUSAND FIVE HUNDRED & NINETY FOUR ONLY


108

Table G.4


line from BFIDC manifold station to CGS Fouzdarhat (4th segment)

Sl

no.



Tk./km

12.81 km 2300419.80

2 Transportation, hauling of pipes


construction site.

58.49

Tk./ton-km

2028.25

40

ton

km

4745293.70 Assuming 40

km distance.





depot to work site.

107.26

Tk./ton-km

200

40

ton

km

858080.00 Assuming 40

km distance.


Right-of-way (ROW)

290.19

Tk./mtr

12810 mtr 3717333.90



3355.17

Tk./mtr

1000 mtr 3355170.00





16096.60

Tk./no

1090

nos. 17545294.00

(continued)

109

Sl

no.




API.1104



sand blasting.

587.33

Tk./mtr

12810 mtr 7523697.30





1293.55

Tk./mtr

12810 mtr 16570375.50




1230.00

Tk./no

1090 nos. 1340700.00

10 Trenching 610.08

Tk./mtr

12810 mtr 7815124.80

11 Lowering 491.02

Tk./mtr

12810 mtr 6289966.20





309.96

Tk./mtr

12810 mtr 3970587.60


(continued)

110

Sl

no.



Tk./mtr

12810 mtr 10005250.50


Tk./mtr

12810 mtr 3991596.00




LS 369000.00




LS 369000.00




Nitrogen)

85047.12

Tk./km

12.81 km 1089453.61



and drawing.



Rail crossing = 03 no. (assumed 12

mtr each)

12226.20

Tk./mtr

60 mtr 733572.00


(continued)

111

Sl

no.


Road Crossing = 02 no.(assumed 12

mtr each)








launcher


Tk./no

1090 nos. 8887489.40





30381000.00





3198 Tk./no 12 nos. 38376.00


Total 138883180

In words: THIRTEEN CRORE EIGHTY EIGHT LAC EIGHTY THREE THOUSAND ONE HUNDRED & EIGHTY ONLY


feasibility study of intelligent pigging in the ring main - BUET

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