Final EIS report

Engineer In Society ( VAB 4042 ) Project Report

ENGINEER IN SOCIETY

HOT TAPPING PROJECT

BY

Siti Hajar Binti Jaafar ( 9710 )

Emi Zurima Binti Ismail ( 9136 )

Nor Wani Idayu Binti Ab Wahid ( 10266 )

Nurul Zahidah Binti Md Hasidin ( 10809 )

Noor Azreen Binti Mohd Faizol ( 10902 )

April 2011

Universiti Teknologi PETRONAS

Bandar Seri Iskandar

31750 Tronoh,

Perak Darul Ridzuan

1


EXECUTIVE SUMMARY

We started the case study by choosing the hot tapping project that had been

conducted at PETRONAS Carigali Sdn Bhd, Peninsular Malaysia Operation (PCSB

PMO). The main objective of hot tapping is to install new flare meter at Resak and

Duyong flare header line at Onshore Gas Terminal (OGT) to calculate the amount of

product being flared because the quality and performance of plant is based on the value

being calculated. The few metering systems are installed at the flare pipelines without

any hazards to determine quantity such as Mass, Volume and Energy and quality of

material to be delivered within specific uncertainty limits

The project took about a month to be done for specific pipelines at the PCSB

PMO. As the project being conducted, it must follow schedule which will be discussed

in detail in Work Breakdown and it shows how important project management is in the

every aspect of life especially in industrial world. Besides, precaution, safety aspects,

operating conditions and instruments have to be followed which will be discussed in

details in Health and Safety issues.

The scope of study for the hot tapping project is basically on how to conduct hot

tapping project in specific operating conditions at specific pipelines locations for the

OGT at PCSB PMO with Trisystems Engineering Sdn Bhd as contractor and TMM

Engineering Sdn Bhd as mechanical contractor

At the end of the project, the objective which is to install new flare meter at

Resak and Duyong flare header line at Onshore Gas Terminal (OGT) to calculate the

amount of product being flared because the quality and performance of plant is based on

the value being calculated, had been achieved successfully without any hazard occurred.

2


TABLE OF CONTENT

Content Page

Executive Summary 2

Table of Content 3

List of Figures and Tables 4

Introduction & Background of The Project 5 - 6

Organization Chart

PCSB PMO

Maintenance Engineering Department

Hot-Tapping Project

7

8

9

Environmental Impact 10

Work Breakdown

Project Life Cycle

Logical Sequence of Activities

Level of Work Breakdown Structure

11

11 – 12

12 - 16

Activities Estimation

Procedures

Close-up procedures

17

18 - 26

Cost Estimation 27 - 35

Scheduling 36 - 39

Health & Safety Issues

Compliance to authority standards and guidelines

Hazard Observation

40 - 41

41 - 43

Discussions & Recommendations

Discussion of the outcomes

Recommendations

Conclusions

44 - 45

46

46

Appendices 47

References 48

3


LIST OF FIGURES

Content Page

Figure 1: Organization Chart of PCSB PMO 7

Figure 2: Organizational Chart of Maintenance Eng. Dept. 8

Figure 3: Organization Chart of Hot Tapping Project 9

Figure 4: Project Life Cycles Stages 11

Figure 5: Sequence of Activities vs. Time 12

Figure 6: Level of Work Breakdown Structure 12

Figure 7: Fit-up Work 18

Figure 8: Leak Test on Welding Joint 19

Figure 9: Tightening and Untightening in cross sequence 20

Figure 10: Gaskets 20

Figure 11: Valve Installation 20

Figure 12: Hot-Tapping Machine 21

Figure 13: Leak Test on Hot tapping Machine / Gate Valve 22

Figure 14: Fixing Pitot Drill and Boring Bit 23

Figure 15: Tightening Hot-Tapping Machine 23

Figure 16: Leak Test on Hot tapping Machine using Nitrogen gas 24

Figure 17: Cutter pass check, cutting travel measurement,

alignment using manually

24

Figure 18: Hot Tap Perforation 25

Figure 19: Probe Installation 26

Figure 20: Exhibit 5 and Exhibit 6 34

Figure 21: Exhibit 7 and Exhibit 8 34

Figure 22: Project Gantt Chart 36

Figure 23: Fire Triangle 41

Figure 24: Possible gas leak identified and covered 43

Figure 25: Gas detector and Fire water 43

LIST OF TABLES

Content Page

Table 1: Description on Project Manager’s Role 13

Table 2: Method of Magnetic Particle Inspection (MPI) 19

Table 3: Exhibit 3 29

Table 4: Exhibit 4 32

Table 5: Project Description based on Gantt Chart 37 - 39

4


INTRODUCTION & BACKGROUND OF PROJECT

Hot Tapping is the method of making perforation on the online line without the

interruption of emptying the section of pipe safely. This means the pipe can continue to

be in operation while maintenance or modifications are being done to it. The hot tapping

also used to drain off pressurized casing fluids. In this hot tapping, the heat must be

distributed to the flow to minimize the risk of explosion.

Hot tapping can be done to most any type of pipe, ranging from carbon steel to

PVC that contain water, oil, gases, fuels, steam and other chemical substances with

specific temperature and pressure condition. Pressures up to 1440 Pascal at 100° can be

Hot Tapped safely without any interruption of service.

Typical Hot Tap installation consists of a tapping saddle, gate valve, and Hot

Taping Machine. The installation is tested, the valve is opened, and the cutter and pilot

drill advanced. When the cut is completed, the cutter and pilot drill are retracted, the

valve is closed and the Hot Tap Machine is removed. [ i ]

There are three types of hot tapping which is tapping on tangential of pipeline,

tapping not on tangential (offset tapping), twisted and not on tangential of pipeline. At

OGT, there are two types of pipelines used which is High Pressure (HP) and Low

Pressure (LP) pipeline.

For HP pipeline, the tapping types are flow transducers: offset tapping, pressure

transmitter: tangential tapping and temperature transmitter: tangential tapping where for

LP pipeline, the tapping types are flow transducers: twisted and offset tapping, pressure

transmitter: tangential tapping, temperature transmitter: tangential tapping.

5


In this report, the scope of study is basically on Hot Tapping and perforation

(making holes) that were done to the existing pipelines at Onshore Gas Terminal (OGT)

in PETRONAS Carigali Sdn Bhd, Peninsular Malaysia Operation (PCSB PMO) to tie-in

the new nozzle installation.

A few metering instruments such as flow transducers, temperature transmitters

and pressure transmitters are installed on the flare pipelines to measure the flared gas to

keep track on where the product goes and the percentage. The operating condition

during the entire hot tapping process must be monitored crucially as the pipelines

pressure must not exceed maximum gas pressure that will absolutely contributed to

hazard such as explosion and fire.

6


ORGANIZATION CHART

Figure 1: Organization Chart of PETRONAS CARIGALI SDN BHD, PENINSULAR MALAYSIA OPERATIONS

7

GENERAL MANAGER (PMO)

MANAGER(REGIONAL PLANNING

SENIOR MANAGER

(PRODUCTION)

SENIOR MANAGER(MAINTENANCE ENGINEERING)

SENIOR MANAGER(RELIABILITY INTEGRITY

ENGINEERING)

MANAGER(WELL INTEGRITY

ENGINEERING)


Figure 2: Organization Chart of MAINTENANCE ENGINEERING DEPARTMENT

8


Figure 3: Organization Chart of HOT TAPPING PROJECT

9

CLIENT

PETRONAS CARIGALI SDN. BHD (PCSB PMO)

To plan the schedule of the project.

To lead the project. To organize

appropriately about the project.

To prepare the costing of the project.

MECHANICAL CONTRACTOR

TMM ENGINEERING In charge on mechanical

part. In charge on equipment. Responsible to do welding

and perforation process.

MAIN CONTRACTOR

TRISYSTEMS ENGINEERING SDN. BHD (TRI)

In charge on electrical and instrument part.

Responsible to do installation of metering instruments and electrical.

PROJECT MANAGER

Mr. M Fallah bin Mohamed To lead the project

and supervise the contractor involved.


ENVIRONMENTAL IMPACT

By performing a shutdown interconnect with low or high pressure system will

give an impact on environmental. Gas vented from the pipeline segment represents a

loss of product and an increase in methane emission. From the record, up to 6000 cubic

feet natural gas vented to make a new connection or non-leaking repairs.[ ii ] The

quantity is depends on pipe diameter, length between isolation valves and operation

pressure. For example, a shutdown connection on a steel can require one to three or

more days if pipeline outage and possible interruption of natural gas shipments in

addition to the release of methane to the atmosphere.

Methane is difficult to transport from its source. Generally it will be transported

in bulk by pipeline in its natural gas form. It is a relatively potent a greenhouse gas.

Compared with carbon dioxide, it has a high global warming potential of 72 (calculated

over a period of 20 years) or 25 (for a time period of 100 years). It is also affects the

degradation of the ozone layer. Large amount of methane are produced anaerobically by

methanogenesis. [ iii ]

So, hot tapping is an alternative technique that allows the connection to be made

without shutting down the system and venting gas to the atmosphere. With that, the

quantity of methane gas at atmosphere will be reducing. Hot tapping will avoided

cutting, realignment and re-welding of pipeline sections. It will also avoid inserting or

gas-freeing pipeline section for hot work. In other side, hot tapping also can reduce

planning and coordination costs.

10

2.PLANNING

4.DELIVERING

1.DEFINING

3.EXECUTION

Project Life Cycle


WORK BREAKDOWN

Project Life Cycle

By general definition, project is taken to create a unique product or services where we

have to invest our time, money and resources in hope of a return. In the Hit Tapping

Project, four stages in sequence are done to follow the timeline. The four stages are:

Figure 4: Project Life Cycle Stages

Logical Sequence of Activities

In Hot Tap Project, each stage of life cycles is done by different types of team

according to their area of works. In defining stage, there are 3 minor stage will be done

which is inception, definition of project and proposal preparation which done by the

project manager. Organization chart of the project is created which included the main

contractor, mechanical contractor and the client. The job scope has been defined to all

members.

11


During planning stage, the Planning, Organizing, Leading and Controlling

(POLC) level is being used. The planning is satisfied by top management and completes

the strategies using the resources of time, money, team members, material of the

pipeline, installed instrument, drilling equipment, welding, and perforation process.

Leading is by directing each team to complete their jobs within time using motivating

methods and good communication skills. Finally, manager has to control the project

flow with respect to time, cost, and quality of the flared gas.

Execution stage is important because this is where the construction begins. The

metering instrument is installed regarding to the sequence and the drilling, welding, and

perforation process is done in safe environment by following the HSE standard. After

construction is done, we reach the final stage, delivering. This is where we handing over

the process of plant. The project life cycle is simplified in the diagram below:

Figure 5: Sequence of Activities vs. Time

Levels of Work Breakdown Structure

Work breakdown is the schedule which guides all the teams to develop the project

according to the timeline. Work breakdown structure is divided into three main phases

which is Initiation Phase, Development Phase, and Procurement Phase.

12


Figure 6: Level of Work Breakdown Structure

To make sure that the yield flared gas, installation and perforation process of Hot tap

Project is follows the requirement and standard given, several task need to be completed

in sequence so that the project will complete before or on time.

1) Initiative Phase

This task is done by the project manager where he has to make sure that the

strategy chosen will be manage in sequence according to plan. The task of

project manager in initiative phase is described in the following table:

TASK DESCRIPTIONProject Initiation Initiation of project that fulfill client’s need and

standard requirement. The client, PETRONAS Carigali Sdn Bhd want the project is done without shutting down the process of plant and the heat can be measured from digital meter installed on the pipeline.

Project Directive Basic direction of the project flow which includes the scope and procedure on how to complete the task. The direction is given including the duration of the drilling, welding, installation and perforation process.

Project Requirement Specification

Follow the standard and requirement highlighted by client or project director to be completed by management, design, engineering and construction teams. Project manager will manage the flow of project, electrical and mechanical engineering teams will do the installation of metering instrument and

13

WORK BREAKDOWNOganization

INITIATIVE PHASEProject Manager

DEVELOPMENT PHASEEngineer/Constructor

Electrical Mechanical

PROCUREMENT PHASE

Closure Phase


construct the related equipment to the flare pipeline.Project Management Plan Defines the objectives, scope for implementation,

installation and the task responsible for each team.Construction Management Plan

Build and develop the project according to the requirements in a manner rules for electrical and mechanical area.

Work Breakdown Structure Develop a structure for completing project according each subordinate and working area.

Table 1: Description on Project Manager’s Role

2) Development Phase

There are four main responsibility which is electrical and mechanical

engineering, inspection group, execution foreman and operations.

a) Engineering

Engineering responsibility includes design of nozzle and its support, type of

inspection of the parent wall for example, the radio graph and/or ultra-sonic

inspection, welding method and procedure, valve selection and specification

of test pressures, method of testing and the test media, appropriate drawings

and files up-dated. Special consideration must be given to testing media due

to parent wall temperature and thickness. The engineer or tapping technician

will assist other involved groups in the evaluation, planning, and execution.

The parent metal, at the immediate location of the hot tap, shall be inspected

prior to the welding of the nozzle onto the line, and vessel. The type, design

and temperature of the parent metal will determine the type of wall

inspection. The engineer will determine if Corporate Engineering Team

should be contacted. Typically, but not limited to, Corporate Engineering is

14


contacted prior to performing a high risk tap and / or line plug for example,

lethal services, pressures greater than 1000 psig and/or temperatures greater

than 600 oF.

b) Inspection Group

The Inspection Group which consists of the project manager and supervisor’s

representative will review and determine materials of construction, hot tap

location wall thickness. Inspection Group representative will also recommend

the welding method and procedure to the engineer. The Engineer will make a

decision concerning x-raying of the hot tap valve and any other special

testing or inspection requirements or procedures.

c) Execution Foreman / Mechanical Planner

The Execution Foreman / Mechanical Planner is responsible for all phases of

the planning, ordering, and execution of the job. In conjunction with the

Inspection Group the Execution Foreman / Mechanical Planner is responsible

for the proper inspection of the tapping and / or plugging machine, and

witnessing of all tests specified by Engineering.

d) Operations

15


The Operations Engineer / Planner are responsible for the initiation and

completion of the hot tapping data list used for preplanning and submitting

these sheets with the permit request. With assistance from other groups, as

required, the specification of department number, line or equipment number,

process conditions, justification and the safety review for a hot tap or plug is

also included in the client's responsibility. At the completion of the job, the

planner will send one copy of the completed data sheets to the responsible

mechanical engineer; including the recovered coupon.

3) Procurement Phase

The Procurement phase is where the Hot Tap is installed based on the request

from the client after the Development phase completed. The quality of Hot Tap

on flare pipeline is monitored by the procurement team and construction

engineering team. Before Hot Tap is installed in real plant process pipeline, there

are several samples of Hot Tap being tested by the quality team during

experimentation. This is to ensure that the product does not have any issue in

terms of operations and functionality. The installation and perforation process

must be within the estimated cost and time given before the deadline to avoid

any additional in cost and delay time to the client and plant process. If the

products are not settled at the agreed time between the company and the client,

there will be a penalty and bad reputation to the company. After the Procurement

phase and delivery of the products to the customer, the project comes to the

closure. Finally, in the Closure Phase under Procurement Phase, the Project

Manager issues the Project Closure report to the Corporate Engineering Team.

16


The details of the project are attached such as the documents related to the

project including the planning, designs, development and procurement. The list

of the items is mentioned in the handover checklist documents.

ACTIVITIES ESTIMATION

This project can be generally classified to two major parts, Hot Tapping (welding,

installation of isolation valve and perforation of pipeline) and Installation of metering

instruments (Flow transducers, temperature transmitters and pressure transmitters.)

Procedures:

1. Pre-works

2. Hot tapping works

3. Leak test on welding joint

4. Valve installation

5. Preparation of hot tap equipment

6. Fittings of hot tap equipment on the valve

7. Leak test of hot tap machine set up using Nitrogen gas.

8. Cutter pass check and cutting travel measurement, alignment using manually.

17


9. Connecting high pressure air hoses between hot tap machine and power unit/air

compressor.

10. Hot tap perforation.

11. Bleeding off gas after first penetration and after perforation completion.

12. Releasing pressure from hot tap machine after completion.

13. Unbolting hot tap machine from tapping valve.

14. Probe installation

15. Housekeeping.

Close-Up Procedures:

1. Pre-works

The pre-works are mobilization or demobilization of equipment, machinery and

manpower to site including loading and unloading, equipment inspection, refueling

diesels for gen sets and lifting activities using cranes.

2. Hot Tapping Works:

i. Fit-up: Fittings are measured and cut accurately to fit the pipeline before

perforation. Pipeline is measured and marked to make sure the fittings are

accurately aligned to the pipeline.

18


Figure 7: Fit-up work

ii. Grinding: Pipeline is grinded before welding to remove paint and coating on

the welding spot.

iii. Welding: There are four phases of welding: Tark (welding points on the

pipeline just as markings of where should the nozzles will be welded), Root

Pass (welding around the nozzle circumference.), Hot Pass (several layers of

welding) and Buffering (final layer of welding)

3. Leak Test On Welding Joint

Welds are tested to make sure its robustness. One of weld tests is by using the

Magnetic Particle Inspection (MPI) technique to test the continuity of the

welding. There are two methods of MPI:

Using dry powder Using wet solutionCan be used directly even when the surface is still hot.

Can be used to cold surfaces only (wait until surface is cold).

Table 2: Method of MPI

Principle of MPI:

19

N SN S

SN


Figure 8: (a) no cracks/discontinuity (b) cracks/discontinuity on the welding

If there is no crack or discontinuity of the welding, the iron particles will be

attracted to the U-magnet. If there is discontinuity on the welding, the metal became lots

of magnets (poles formed magnets). The iron particles will not attracted to the U-magnet

but it will be attracted to the cracks. The tubing and fitting have to be check to make sure

they are properly fitted, control valve operational, ball valves and other venting outlets

are in close position and all bolts and nuts are in tight condition.

4. Valve Installation

i. Tightening and untightening bolts in cross sequence.

Valve is installed on the branch fitting Nuts and bolts are put randomly.

Sphere wound gasket is inserted The bolts are tightened cross sequence.Figure 9: Tightening and untightening bolts in cross sequence

ii. Gasket

20


Gasket is chosen according to the pipeline size and type. In this project, we

use sphere wound and should not have scratch to ensure no leakage

Teflon sphere wound gasket Graphite sphere wound gasketFigure 10: Gaskets

iii. Valve installed as isolation valve : Ball valve class VI is used

Figure 11: Valve Installation5. Preparation of Hot Tap Equipment

Visit TMM Engineering Sdn. Bhd. to check the operation of the hot-tap equipment.

Tests conducted during the inspection.

Equipment used:

i. Hot tapping machine

21

Temperature transmitter

point

Pressure transmitter

point

Ultrasonic Flow transducers point

LP

HP pipeline


Hot tapping machine

The pilot drill for the hot tap machine T-101

Coupon cutter 1 ½” drilling bit

2 ½” drilling bit ¾” drilling bitFigure 12: Hot Tapping machine

Tests conducted:

i. Leak Test of Hot Tap Machine/Gate Valve

1. Hot tap machine T-101 is the smallest hot tap machine. The drilling machine is mounted to the metal disc as a replacement to the hot tap valve.

2. Hot tap machine T-101 assembly is connected to the nitrogen gas tank for leak test. Nitrogen gas is used because it is not hydrocarbon gas and cannot produce fire.

22


3. Pressure supplied is for testing is about 5 bars. This pressure must maintain for about 5 minutes to show that there is no leak on the machine.

4. Snoop liquid which is a soap based liquid is applied at the mounting point to test if there is leak

5. Snoop is applied to the marking area to check whether there is leakage.

6. Snoop liquid: leak detector

Figure 13: Leak Test of Hot Tap Machine/Gate Valve

ii. Fixing of pitot drill and boring bit

Drilling bits are attached to the hot-tapping machine. We run the hot tap

machine and observe the movement of the drilling bit. The drilling bit

will be adjusted until it rotates straight on the exact point to ensure

accurate drilling point.

23


Figure 14: Fixing pitot drill and boring bit.

6. Fittings Of Hot Tap Equipment On The Valve

Hot tap machines are tightened to the valves before any perforation done on the

pipeline.

The hot tapping machine is mounted in the valve.

Tightening the hot tap machine by cross sequence.

Figure 15: Tightening Hot Tapping machine

7. Leak Test of Hot Tap Machine Set Up Using Nitrogen Gas.

24


Nitrogen gas is injected for leak test and to vent out oxygen gas.

Hot tapping machine is powered by pneumatic. Genset supplies = 7bar

Masking tape is wrapped around the mounting between the hot tapping machine and the valve.

Nitrogen gas injected 2.5 bars. Pressure injected must be higher than operating pressure in the pipeline. . Pressure of the gauge drop indicates leak of the hot tapping machine.

Figure 16: Leak Test of Hot Tap Machine Set Up Using Nitrogen Gas.

8. Cutter Pass check and Cutting Travel Measurement, Alignment using

manually.

Height of the valve and branch fitting is measured. Travel length is the length for the drilling bit being screwed up/down during and after perforation.

Alignment of the boring bit is adjusted according to the travel length to make sure that drilling bit is taken out without being stuck when the isolation valve is closed after perforation is done.

Figure 17: Cutter Pass check and Cutting Travel Measurement, Alignment

9. Connecting high pressure air hoses between hot tap machine and power

unit/air compressor.

10. Hot tap perforation.

25

Nitrogen gas injected=1.1 x operating pressure

Cutting travel length

Marking line for boring bit.


A non-hydrocarbon gas, Nitrogen gas is injected to suppress oxygen in the air to

eliminate one element of the fire triangle.

Before perforation:

Valve is in open position. Then, Nitrogen gas is injected to the hot tapping

machine after it is mounted to the isolation valve. The bleed valve is opened;

Nitrogen gas is injected again for about 2 seconds to purge out the natural gas

inside the valve chamber that may contain oxygen which can cause explosion.

Bleed valve is closed, nitrogen gas supply stopped. Nitrogen gas inside the

chamber is 2.5bar. Perforation is done.

After perforation:

Perforation is confirmed when pressure on the gauge drops to atmospheric

pressure. Drilling is complete when the hot tapping machine reached marked link.

Pipeline is tapped. Tapping is confirmed when pressure drops. From 2.5 bars on the hot tapping machine gauge. The pressure after tap is the pipeline pressure

Figure 18: Hot Tap Perforation

11. Bleeding Off Gas After First Penetration and After Perforation Completion.

12. Releasing Pressure from Hot Tap Machine After Completion.

26


13. Unbolting Hot Tap Machine From Tapping Valve.

14. Probe Installation

Temperature transmitter Flow transducer (horizontal) Sensor element (horizontal)

Flow transducer (vertical ) Sensor element (vertical) Pressure transmitter

Flow computer Flow computer

Figure 19: Probe Installation

15. Housekeeping.

COST ESTIMATION

27


Operators can assess the economics of performing a hot tap as an alternative to a

shutdown connection by following the five steps below:

Five Steps for Assessing Hot Tap Economics:

i. Determine physical conditions of existing line.

ii. Calculate cost of performing a shutdown interconnects.

iii. Calculate the cost of a hot tap procedure.

iv. Evaluate the gas savings benefits of hot tapping.

v. Compare the options and determine the economics of hot tapping.

Step 1: Determine physical conditions of the existing line.

To ensure safety and as a preparation of hot-tapping project, operators need to

determine the maximum operating pressure (during the hot tap), type of pipe material

(steel, cast iron, plastic), condition of the parent pipeline (internal/external conditions

to evaluate include the location of nearby valves for emergency and corrosion, wall

thickness) to assure a safe project, location of nearby valves for emergency isolation in

the event of an accident, desired tap diameter depends on size of pipeline involve,

working space around the connection, location of other pipeline welds and

imperfections or obstructions. Operators should also determine if the line is “looped,”

as many gas transmission companies avoid operational disruptions by shifting the load

to a parallel line. It is advisable to develop and follow a written plan to assure full and

proper evaluation of a future connection.

28


Step 2: Calculate cost of performing a shutdown interconnect.

To tap a new point on a pipeline, there are two options, either to shutdown

interconnects or keep the pipeline online while hot-tapping is done. Thus, it will be

important to calculate the cost of both options. The cost of an actual project would

include Direct costs (Material and equipment, welding requirements, quality control,

blow down and purge costs, labor, and scheduling expenses) and Hidden costs (Cost

of shut-off valves, advertising if service is to be interrupted, relighting of customer

services, and excavating for stopples and purge connections). Operators would be

advised to reference historical data to determine these costs. For the purposes of this

scoping analysis, material and labor costs for cutting out the line section and welding

in a tee connection in the shutdown method are assumed to be comparable to the cost

of welding on the fitting and performing the hot tap when the branch connection is the

same size as the pipeline. However, the costs of the gas lost through venting and inert

gas purging are unique to the shutdown interconnect. The formulas used to determine

the cost of a shutdown interconnects are shown in Exhibit 3. For these calculations,

low pressure is defined as less than 2 psig. For comparative purposes, calculating the

cost of a shutdown interconnects should take into consideration a multiple-project

scenario. This multiple-project perspective allows for a more complete comparative

cost analysis given the up-front capital costs of owning and operating a hot tap

machine and the need to perform several interconnections throughout a given year.

Exhibit 4 illustrates how the cost calculations in Exhibit 3 can be applied in a

multiple connection scenario. The hypothetical situation presented includes several

29


projects on pipelines of various sizes and pressures. Cost calculations, however, are

only provided for the 4-inch pipeline scenario and only cover direct costs.

30

Exhibit 3: Calculating the Cost of Shutdown Interconnect

Given: D = diameter of pipeline (inches) T = tap hole diameter (inches) - for low pressure shutdown with tap holes for stoppers L = length of pipeline between tap holes (feet) - for high pressure shutdown P = line pressure (psia for low pressure, psig for high pressure) Ppgas = current purge gas market price ($/Mcf) - assumed $4/Mcf Pg = current gas market price ($/Mcf) - assumed $3/Mcf Ce = cost of extra excavation, use company records ($) Cp = cost of purge connections and excavation Cs = cost of hidden shutdown expenditures, see Appendix ($) Cf = cost of fittings, see Appendix ($) Time Taphole is open = from prior experience (minutes)

Calculate Direct Costs:

1. A=area of pipeline ( ft2 )=3.14∗D2

4∗144 ( ft2

¿2 )=( D2

183 )2. V p=volume of pipline ( Mcf )= A∗L

1000 ( Mcf

ft3 )3. V p=volume of pipline ( Mcf )= A∗L

1000 ( Mcf

ft3 )4. V pgas=volume of purge gas=V p∗2.2(shutdown+restore

+20%wasted )5. C pgas=cost of nitrogen purge gas=V pgas∗Pgas

6. V g=volume of gas lost∈high pressure systems :

V g ( Mcf )=D2∗P∗( L

1000 )∗0.371

1000

7. V g=volume of gas lost∈low pressure systems :V g (Mcf )

=T2∗P∗No .of Taphole s∗Time tapole is open

60 ( hrmin )

8. Cg=cost of gas lost ($)=V g∗Pg

Calculate Indirect Costs:1. Calculate Ce = cost of extra excavation for tie-in ($)


Table 3: Exhibit 3Additional factors that are company specific include gas leakage past the pipeline

valves on both ends of the shutdown, number of stoppers, tap holes for venting and

purging, and type of purge gas. Leakage is particularly important as large pipeline block

valves can leak significant volumes of gas because they are used infrequently and the

valve seat can accumulate debris that inhibits a tight seal. The volume of leakage is

highly variable, dependent on valve type, age, pipeline pressure and service (dry gas

causes much less corrosion and accumulation of debris than wet gas). If a partner’s

individual evaluation following this lesson learned results in marginal economic

justification, then company experience on pipeline valve leakage 9 should be factored in

to improve the economics.

Step 3: Calculate the cost of a hot tap procedure.

When comparing the up-front costs of hot tapping with shutdown interconnects

the only significant difference is the cost of the hot tap equipment. The tee fitting or full

encirclement sleeve and the valve have nearly the same cost for either method when the

branch is essentially the same size as the pipeline. The cost of welding a full

encirclement sleeve is nearly the same as the cost of welding a tee fitting in a line.

Labor cost for cold cutting the pipeline and hot tap cutting out a coupon are

sufficiently close for this type of feasibility evaluation. Maintenance costs apply only to

hot tap equipment, such as drill sharpening and other equipment care and replacement.

Tapping machines come in several sizes, and a single machine can perform hot taps

31


from 3 to 12 inches. Less expensive machines can be purchased to perform small taps. In

general, capital costs for purchasing the hot tap machines typically used by gas

companies for the most common sized connections range from $13,200 to $23,000.

Equipment cost is normally a one-time capital expenditure and can be

depreciated over the life of the equipment, typically 15 to 20 years. Each company,

however, should calculate the depreciation in the same manner used for other equipment

purchases. This should be considered in conjunction with how often the machine will be

used in the future. To make this determination, operators should look at company

records to determine the number of times similar connections have been performed.

Typically, a company that performs several hot taps a year will find it economical to

own the equipment, especially in sizes up to 12 inches, and to maintain trained personnel

to perform the service. These jobs are usually simpler and require less specialized

training than larger hot tap jobs. For larger and less frequent hot taps a company might

consider it more cost effective to hire a contractor who will supply the equipment and

trained personnel. Most hot tap vendors will supply all necessary tapping equipment,

including the drilling machine, fittings, valves, cutters, and repair services. The majority

of vendors also offer contract services for larger or infrequent jobs, or will rent out the

tapping equipment. Supplying support services, such as excavation, welding, and cranes,

can reduce the costs of using an outside contractor.

Other factors, such as the line material and thickness, system pressure, and

temperature, should also be considered when determining the alternatives of purchasing

hot tapping equipment or hiring contractors. A company should evaluate how often the

32


tapping equipment would be used and if they would realize savings by owning and

maintaining the equipment and training operators.

33

Exhibit 4: Hypothetical Scenario and Example Calculation of Lost Gas and Purge Gas Costs for a Shutdown Interconnect

Given: A pipeline company requires numerous shutdown or hot tap connections as follows: Pipeline Diameters, Inches 4 8 10 18 Pipeline Pressures, psig 350 100 1,000 200 Pipeline Lengths1, miles2 2 1 3 2 Annual Taps3, number 250 30 25 15

Vg ( Mcf )=

D2∗P∗L1000

∗0.372

1000

V g=(42∗350∗( 2∗5280

1000 )∗0.372)1000

V g=−22 Mcf

(2) Calculate: Vpgas = Volume of Purge Gas 4

Vpgas ( Mcf )=( D2∗L

183 )1000

∗2.2

Vpgas ( Mcf )=( 42∗2∗5280

183 )1000

∗2.

Vpgas=2Mcf

(3) Calculate: Value of Gas Lost by Shutdown Interconnects (Including Purge Gas) Calculate: Value of Gas Lost by Shutdown Interconnects (Including Purge Gas)

Cost=Cg Cpgas=V g∗Pg+V pgas∗Ppgas

Cost=(22Mcf∗$ 3

Mcf )+(2 Mcf∗$4 / Mcf )

Cost = $74 for each of the 4 inch pipeline shutdown interconnects


Table 4: Exhibit 4

The procedures described above are general guidelines for preliminary economic

assessment and can differ from company to company. Additional factors that are

company specific include gas leakage past the pipeline valves on both ends of the

shutdown, number of stoppers, tap holes for venting and purging, and type of purge gas.

Leakage is particularly important as large pipeline block valves can leak

significant volumes of gas because they are used infrequently and the valve seat can

accumulate debris that inhibits a tight seal. The volume of leakage is highly variable,

dependent on valve type, age, pipeline pressure and service (dry gas causes much less

corrosion and accumulation of debris than wet gas). If a partner’s individual evaluation

following this lesson learned results in marginal economic justification, then company

experience on pipeline valve leakage 9 should be factored in to improve the economics.

Exhibit 5 presents ranges of hot tapping costs for both equipment purchase and

contracted services. The cost ranges shown include all materials; additional expenses

will result from labor and maintenance expenditures, as discussed above. Vendors state

that the operations and maintenance (O&M) costs can vary greatly, depending on the

number of taps performed and equipment and procedural care.

Exhibit 6 shows the equipment, O&M, and contractor services cost to per-form

the 320 taps per year in the hypothetical scenario first described in Exhibit 4. The

34


assumption is made that the 4”, 8”, and 10” taps (a total of 305 taps) would be

performed by the company. Because few taps equal to or larger than 18 inches are

performed each year, these taps (a total of 15 taps) would be contracted to vendors. The

equipment cost includes the purchase cost of two small (<12”) tap machines. For the

purpose of this lessons learned, the average value of the purchase, O&M, and

contracting service costs listed in Exhibit 5 are used to complete the cost analysis for the

hypothetical scenario. Based on these assumptions the total equipment cost is calculated

at $36,200, the O&M cost at $5,500 and the contract services cost at $37,500.

Figure 20: Exhibit 5 and Exhibit 6

Step 4: Evaluate the gas savings benefits of hot tapping.

Exhibit 7 presents the natural gas and purge gas savings associated with hot

tapping on small and large diameter high-pressure pipelines in the hypothetical scenario

of 320 taps per year. The values are calculated using the equations in exhibit 3,

multiplied by the number of annual connections. Gas losses associated with shutdown

interconnects are the primary savings when these connections are made by hot tapping.

35


Figure 21: Exhibit 7 and Exhibit 8

Step 5: Compare the options and determine the economics of hot tap-ping.

The economic analysis shown in Exhibit 8 compares the significant cost and

benefit differences between hot tapping and shutdown interconnections for the

hypothetical scenario of 320 taps per year. The significant costs are the purchase,

operation and maintenance of hot tapping equipment and/or contracting for hot tapping

services. Here, both costs are included: the purchase of two hot tapping machines for

$36,200 for the smaller sizes and contracting the 15 large taps at $37,500 per year. The

purchased hot tap machines are operated and maintained at $5,500 per year. All these

costs are calculated in Exhibit 6. Many expenses, including the cost of fittings, valves

and basic labor, are assumed to be similar in both hot tap and shutdown procedures, and

can be excluded in the comparative analysis. A more complete analysis can be done by

evaluating and including the company specific “hidden” costs per Exhibit 3. The

significant benefit differences are the reduction in natural gas loss by eliminating

venting and the inert purge gas used in the shutdown interconnect procedure. As

summarized in Exhibit 7, annual natural gas savings total 24,440 Mcf for the

hypothetical hot tapping scenario, worth $73,320 per year at $3 per Mcf gas price. The

36


annual inert gas savings of 1,710 Mcf is worth $6,840 per year at $4 per Mcf of

nitrogen, for a total annual benefit of $80,160.

In conclusion, hot tapping has been found to be more cost effective than

shutdown interconnects. Even when the system must be taken out of service, hot tapping

presents opportunities for both time and cost savings. While hot tapping is a by

companies for reasons other than the gas savings, consideration of the methane reduction

benefits can often serve to justify hot tapping over the shutdown inter-connect procedure

in a variety of circumstances.

37


PROJECT SCHEDULING

No Task Duration December 2009

January 2010

February 2010

March 2010

April 2010

May 2010

June 2010

1 Feasible study of the project 2 months2 Basic & advanced engineering preparations 1 month4 Procurement 1 month

Present tender plan to the tender committee

Purchase Order (PO) issuance Bidding period Technical & Commercial evaluation Present award recommendation

5 Inspection of materials FAT for metering instruments 3 days

6 Construction management 2 months structure 1 day hot tapping process 2 months installation of metering instruments 1 day Installation and calibration of metering

instruments and the flow computer1 day

Calibration of DCS 1 day7 Commissioning 3 days8 Punch list and close out 1 month

Figure 22: Project Gantt chart

Cycle Personnel involved

38


I. Feasible studyA study is done; discussing the needs and problems faced by the operators of the plant. Identification of problems and the personnel involved will discuss on the solution. Personnel involved are experienced multidiscipline engineers.

PRE Consultants IR engineers Multidiscipline

engineers will be involved in a project study

II. Basic EngineeringInvolves cost estimation, process flow diagram and specification sheets.

III. Detailed Engineering AFC drawing

i. Complete specificationii. Construction drawing

P&ID mechanical flow diagram (MFD), Equipment datasheet, Instrument index, Instrument specification sheet, Block diagram, Junction box, Cable, Terminations, Instrument Installation Standards, Functional logic diagram, Instrument loop sketch, Instrument location drawing, Cable routing and Material Take-Off (MTO)

Multi disciplineProcess, Mechanical, Pipeline, Electrical, Instrument and Civil/construction

IV. ProcurementDuring this stage, project materials will be purchased. Purchase Order (PO) will be issued and all charges on project materials will be under the PO.

Work process flow( Maintenance):i. Project execution

ii. Budget (For PETRONAS):

Engineer in charge

39


i. Proposals

Technical Commercial

Projects which are chosen must be technically acceptable and commercially attractive.Tender committee:For PCSB, there are 3 levels of tender committee.

TC1: >15 Million TC2: 2 Million 15 Million TC3: 500k 2 Million

For PETRONAS, there are 2 levels of tender committees (above 2 Million)

40

Open all technical proposals to be comparedUnpriced

Short listed proposals will be opened to compare prices

Priced

<500k >500k

Register in Quotation committee Open bid SOW Engineering design package: send to PSM

with PR Prepare technical evaluation specifications.

Register in MPP Tender Plan: 2weeks issue out bids Layout for how to execute projects


V. InspectionAfter the purchase, Factory Acceptance Test (FAT) will be conducted to inspect/check the performance of the equipment. Any fault or punch list will be settled during FAT or latest on Site Acceptance Test (SAT).

**Punch list: something that is supposed to be available on the equipment/system purchased but during test/FAT, it is not available or damaged.

Personnel involved during the FAT: Host company: Project holder Contractor 1: Manpower for project execution Contractor 2: equipment provider

Engineer in charge

VI. Construction managementThis phase is where all schedules and project execution takes place.

Engineer in charge

VII. CommissioningAfter project is completed, the project will be tested during Site Acceptance Test (SAT).Any punch list must be fulfilled during SAT.

Engineer in charge

VIII. Punch list and close-outAny punch list must be verified, any problems regarding the project must be settled before project is closed.

Engineer in charge

Table 5: Project Description Based on Gantt Chart

41


HEALTH & SAFETY ISSUES

Hot taps are permissible “only” as a last resort, i.e. when safety, the time required

and/or expense of isolation and decontamination is unreasonable or either of the

preceding are less safe. If the facility is a “covered process” as defined by OSHA

1910.119, then the sites Management of Change (MOC) Procedure must be

followed. If a facility is not a “covered process” then an appropriate safety

review/audit should be performed prior to the execution of the hot tapping/plugging.

A special permit is required for all hot taps according to Safety Procedures, Fire

Permits and Vessel Entry/Fire Permits.

Compliance to Authority Standards and Guidelines

There are several authority standard and guidelines to follow in completing this

project. A lot of safety precautions to be take into account. The standard and

guidelines are;

A. Contact Safety for Sniff Test

B. Permits required are Special Permit, Entry Permit (Vehicle),Welding

Machine, Hot Tap Machine and Other machines or power equipment.

C. Special Safety Requirements are Two (2) points of egression, Sewers in the

area covered, Trapping required to retain welding sparks, Two (2) fire

extinguishers at the Hot Tap site, Periodic Sniff Test, Area enclosed with

barricade tape and Scaffolding if required

Please note that providers must be accredited by the Qualifications Authority, or an

inter-institutional body with delegated authority for quality assurance, before they

can report credits from assessment against unit standards or deliver courses of study

42


leading to that assessment.[iv]. All hot taps should be designed, fabricated, inspected

and tested in accordance with the applicable Codes and Standards. The applicable

standard for pressure vessels is usually the National Board Inspection Code (NBIC)

or API Standard 510, “Inspection, Repair, Alteration and Re-rating of Pressure

Vessels.” These Codes or Standards require that the design of the hot tap should also

be in accordance with the original code of construction. In most cases in the US, this

is typically the ASME Code Section VIII Division 1. In addition, API Recommended

Practice RP 2201, “Procedures for Welding or Hot Tapping on Equipment in

Service,” should also be followed [v]

Hazard Observation

Hot tapping have an explosion hazard. Gas can ignite, causing explosion, death or

serious injury. Tapping into pipe under pressure can cause severe injury if safety

procedures are not followed. No person should make a hot tap unless that person has

been trained and qualified in the use of equipment. Welding is one of element in this

project, but it is the most crucial part of the project. This is because welding involves

heat, hydrocarbon element in the pipeline and also oxygen gas available in the

pipeline. Any carelessness may cause flame/explosion as all the elements in the fire

triangle are available.

Figure 23: Fire Triangle

43


To prevent explosion happen, consider the fire triangle. We must eliminate at least

one of the factors to prevent fire which are flammable materials in the equipment,

combustible materials in the equipment and flammable gas in the atmosphere.

Fire Triangle elements;

i. Oxygen

a. Atmospheric air contains 20.9% oxygen

b. Maintain physical separation between air and fuel as far as

possible

c. Use line packing concept whenever there is a breach of the

physical barrier

i. Pressurize containers such that oxygen cannot step in

ii. Blanketing

ii. Fuel

a. Always present in hydrocarbon and petrochemical facilities

b. Detection methods used to monitor leakages of fuel

iii. Ignition Source

a. Energy is used to operate equipment in the plant

b. Contained based on standards used to define the hazards of

ignition in the plant

44


Figure 24: possible gas leak identified and covered

Figure 25: (a) Surrounding LEL identified using gas detector

(b) Fire water is ready in case of emergency.

Safety Precautions before welding works are;

i. Close/ cover all possible gas leakage/source

ii. Make sure tapping point is far enough from possible leakage source

iii. Identify wind direction by observing wind sock. Wind may bring gas

leakage to the welding area and cause flame

iv. Always measure lower explosion limit, LEL level using gas detector

v. Always make sure that fire water is available when needed in case of

emergency

45


DISCUSSIONS & RECOMMENDATIONS

This last chapter will give the big picture for the hot tapping project’s outcomes,

necessary recommendation and conclusion.

Discussion of the Outcomes

Each year pipelines typically undergo several transformations. Performing hot taps to

make these connections and installations can reduce methane emissions from

pipelines and increase savings and efficiency. The following are several lessons

learned offered by partners and hot tap vendors:

1) Hot tapping has been performed by transmission and distribution companies

for decades. By evaluating the gas savings associated with this practice, hot

tapping can be used in many situations where it would not ordinarily have

been used

2) The site for the branch weld must be free of general corrosion, stress

corrosion cracking, and laminations.

3) Hot tap should not be performed immediately upstream of rotating equipment

or automatic control valves, unless such equipment is protected from the

cuttings by filters or traps.

4) For tapping on steel pipes, fitting generally consist of a welded branch

connection. However, when tapping into cast iron, asbestos cement, or

46


concrete, the fitting cannot be welded onto the existing header. Alternative

fitting attachment techniques, such as a split cast iron compression sleeve or a

mechanical joint saddle, must be employed

5) For plastic systems, the operator should ensure that the hot tapping fittings

are compatible with the type of plastic pipe in the system and appropriate

joining methods are used. Vendors can supply suitable fittings and tools for

almost every kind of plastic system

6) If hot tapping has not been performed in the past, hot tapping procedures

should be developed and personnel trained. Be sure to include instructions

concerning possible burn through or hydrogen cracking during welding

7) All equipment must meet minimum industry and federal standards for

pressure, temperature, and operating requirements

8) If conditions of temperature, pressure, pipe composition, or tap diameter are

encountered that are unusual for your system, be sure to consult the

manufacturer of the tapping equipment or fittings

9) Industry and federal codes and standards should be consulted for more

specific specifications

10) Record emissions reductions associated with using hot taps and submit them

with your Natural Gas STAR Annual Report

47


Recommendations

A decision on whether hot tapping is to be applied shall be based on careful

considerations including at least the following aspect which are;

Safety

Condition of the pipe/equipment under consideration

Configuration of the connection

Code/statutory requirements

Operating conditions

Technical capabilities of the drilling equipment under the operating

conditions (pressure, temperature, nature of product)

Related welding problems

Economic aspects

Environmental/pollution aspects

If hot tapping is to be applied under conditions approaching the technical or

operational limits, specialist advice should be sought

Conclusion

Hot tapping is potentially hazardous and therefore should only be undertaken when

continuity of service is essential or shutdown of the system is impractical and when it

is shown to be technically feasible and to offer a clear advantage over alternatives.

The advantage may be economic and, in some situations, the safety and

environmental risk may be less than those associated with more conventional

48


methods.

49


APPENDICES

Appendix i: Hot Tap Metering Installation Work Breakdown Structure

50

Hot Tap Metering Installation Work Breakdown Structure

1.1.1Product RequirementSpecification 1.1.1.1ProductTraceability

Matrix1.2.1Project Management PlanChecklist 1.2.1.1Project Status Report1.2.2Project Estimation 1.2.3.1Issues Tracker

1.1Project Directive1.2Project Management Plan 1.2.3Issue Management Plan 1.2.3.2Minutes of Meeting

1.2.4Risk Management Plan 1.2.4.1Risk Assessment Tools1. Initiation 1.3Configuration Management 1.3.1Document Master Checklist 1.3.2.1Formal Evaluation ReportPhase Plan

1.4Project Timeline 1.4.1Work Breakdown Structure 1.4.1.1Project Matrix Sheet

2.1.1Schematic Block Diagram2.1.2Bill of Material

2. Development 2.1Electrical 2.2.1Industrial DesignPhase 2.2Mechanical 2.2.2Drilling and Welding 2.2.2.1Tooling

Hot TapMeteringInstallation 3.Procurement 3.1Supplier Management Plan 3.1.1Scope of Work

Phase 3.2Procurement 3.1.2Requisition of Order3.1.3Puchase of Order 3.1.5.1Payment3.1.4Quotation3.1.5Delivery of Order3.2.1Samples Prototype 3.2.1.1Installation Hot Tap

3.2.1.2Prototype Test

4. Closure 4.1Project Closure Report 4.1.1Compile All Related Document 4.1.1.1Handover ChecklistPhase


REFERENCES

51

i www. koppl .com/pdfs/ Hot tap.pdf

ii http://www.globalmethane.org/documents/events_oilgas_20090127_techtrans_day2_robinson3_en.pdf

iii http://en.wikipedia.org/wiki/Methane

iv http://www.nzqa.govt.nz/nqfdocs/units/pdf/10983.pdf

v http://www.carmagen.com/news/engineering_articles/news38.htm

http://www.carmagen.com/news/engineering_articles/news38.htm

http://www.nzqa.govt.nz/nqfdocs/units/pdf/10983.pdf

http://en.wikipedia.org/wiki/Methane

http://www.globalmethane.org/documents/events_oilgas_20090127_techtrans_day2_robinson3_en.pdf

http://www.koppl.com/pdfs/Hottap.pdf

Final EIS report

Documents

Transcript of Final EIS report