GRP Hydrotesting 01.docx

7/28/2019 GRP Hydrotesting 01.docx

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ENI MOD

1. PIPELINES PRECOMMISSIONING

1.1 PURPOSE

The purpose of this document is to establish the minimum functional requirements, to

ensure the correct development of the final hydrostatic tests and their associated activities

in the scope of this procedure.

The purpose of the hydrostatic pressure test is to verify the mechanical strength of the pipe

and piping system components after their construction and ensures they are leak free and

suitable to content and transport the fluid(s) for which they have been designed.

1.2 SCOPE

This procedure covers the activities and requirements required to prepare and perform the

pressure testing of the newly constructed Pipe lines for ENI MOD in accordance with the

Project Specifications and Company Approved Standards.

The newly constructed Pipeline facilities are the following:

No Mat.Diam. Length

Qty

Total

LengthVolumen

HT

Water

Source

Remarks

(Inch) mm (mt) (mt) (mt

3

)1 GRP 40 1,016.0 300 2 600 486.44 WI Direct

2 GRP 28 711.2 19,000 3 57,000 22,643.74 WI Direct

3 GRP 24 609.6 30,000 2 60,000 17,511.81 WI Through No 2

4 CS 24 609.6 1,500 1 1,500 437.80 WI Through No 2

5 CS 20 508.0 2,000 1 2,000 405.37 WI Through No 2

6 CS 20 508.0 6,500 1 6,500 1,317.44 WI Through No 2

Water from WI must be filtered (100 m)

1.3 HYDROSTATIC TEST WATER

Primary impacts associated with the abstraction of water are potential ground water

extraction and modification of stream flows. Secondary issues include minimizing erosion at

intake locations and prevention of fish entrainment into pump suction intakes. Social


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impacts can also be a concern where water is in short supply and abstraction of water could

impact water supplies remaining for the community.

As a common practice no ground water must be abstracted for hydrostatic test use. Water

is extracted from significant water sources such that ground water tables and river flows are

not affected. As a guideline, a maximum abstraction rate of approximately 10% of water

flow in a river or channel could be adopted during water abstraction so as not to have a

significant impact on environmental systems. Additionally, the maximum water abstraction

rate will be subject to assessment to confirm that other users of the supply will not be

adversely affected. Agreement will be required with the water authority and the

environmental regulator, and the relevant permits obtained.

1.3.1 Water Source

The immediate body of water available for the project is located north of the pre-treatment

plant in the same water intake of the MOD project.

1.3.2 Pre-fill Water Quality

Prior to abstraction of hydro-test waters from a source, a water quality analysis will be

conducted to confirm its quality. Samples will be collected and analyzed by an approved

independent laboratory. Field exit water analysis will be conducted at discharge locations to

determine iron Fe levels.

Specifically for Metallic Pipelines with not protective linings, the key parameters and quality

standards required for the hydro test water are:

pH 6.5 to 10.5

Total Dissolved Solids Less than 30 Kg/m3

H 2 S Nil

Suspended Solids 0.005 Kg/m3

Appearance I Turbidity Clear with no visible

sediment


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1.3.3 Water Treatment

In the past, the generally accepted industry practice was to treat all water entering a

pipeline to prevent corrosion. Due to environmental concerns, the current accepted industry

practice is to avoid the use of chemical additives, except under circumstances where the

test water will remain in the pipeline for a period exceeding one month. This practice is

based on the fact that once initial corrosion occurs, the corrosion creates a very thin layer of

rust, and oxygen-induced corrosion will gradually be diminished. The remaining risk to the

pipeline will be predominantly due to the presence of microbiological organisms (e.g. sulfate

reducing bacteria (SRB) and acid reducing bacteria (ARB)).

Should implementation of chemicals for water fitness be required then all test results,

recommended inhibitor type and dosages shall be sent to the Companys representative for

approval prior to start of filling operation.

40, 28 & 24 GRP pipelines have a high resistance to corrosion and the component resins

are resistance to pH values from 1 to 10; therefore the addition of chemicals, if required, will

be only considered and evaluated for the hydrotest water to be use in 20 and 24 Carbon

Steel Pipelines.

For CS Pipelines the final chemical dosage rates will be determined following a water

analysis from the proposed sources taken no earlier than 3 month before operations. Any

water system that contains sulphate has the potential to support the growth of sulphate

reducing bacteria. The problem is not so much the bacteria themselves but rather the

production of corrosive hydrogen sulphide and carbon dioxide gases caused by their

metabolic pathway.

The decision to use chemical treatment will depend on the water analysis and the duration

the water will remain in the CS pipeline. Chemical treatment will be avoided 'wherever

practicable, and especially for short residence time of the hydrotest water in the pipeline

(i.e. less than one month), however when treatment should be necessary the use of

inhibitors and chemicals will be subject to Company approval.

1.3.4 Water Filtering

Water taken from the point of project water intake will be filtered to remove all particles 100 mm

and above.


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1.4 FIELD HYDROTESTING

1.4.1 General sequence of Pipelines Pre-Commissioning Activities

Major activities to consider during the pre-commissioning of the GRP and CS Pipelines are

as follows:

a) Cleaning

b) Gauging (Not Applicable for GRP Pipelines)

c) Filling

d) Hydrotesting

e) Dewatering (Water could remain inside GRP Pipelines ready for operation)

f) Drying (Not Applicable for GRP Pipelines)

g) Lay-up (Water could remain inside GRP Pipelines ready for operation)

Project schedule initiates with the GRP pipelines installation in sequence from water intake

all the way to WPTP, WFTP and then to Basra Regulator.

GRP pipelines will be flooded and hydrotested starting from the two portions connecting the

water intake with the WPTP following with the three 28 GRP pipelines going to the WFTP.

At this stage the water to fill and hydrotest the next sections will be supplied from the

previous sections which conduct the water from Water Intake near WPTP.

Short carbon steel pipelines and remaining two 24 GRP Pipelines will be prepared, flooded

and hydrotested in their mechanical completion order according with the construction

program.

1.4.2 GRP Pipeline

1.4.2.1 Water Filling, Flushing and Venting.

Pipeline should be filled from the lowest point (level) and air should be expelled from the

highest point (level) of the pipeline through air valves. Flow rate of filling should not exceed

5-10 % of the pipeline nominal design flow rate. If it is not possible to fill the pipeline from

the lowest point, additional air valves should be installed.

Just like all other types of pipes, GRP pipelines should also be tested before taking the

pipeline into operation.


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Field tests can be performed with water for purpose to detect any leakage points through

the pipeline.

If the pipeline is tested as a whole, it is rather difficult to detect exact locations of leakages;

it is also difficult and costly to fill / un-fill the whole pipeline. Therefore, the maximum

recommended test lengths is1000m based on the pipeline conditions.

Below points should be checked before water filling and field hydrotesting:

a) Make sure that all truss blocks and rigid structures made of concrete has completed

curing.

b) Ensure that all testing equipment are functional and in good condition.

c) Close and seal the ends of the pipeline section subject to testing with end caps.

d) Ensure that end caps are supported with temporary anchors to resist test pressure.

For visual inspection of the couplings during hydrotesting, 1/3 of top of the couplings are not

backfilled.

Safety precautions should be applied around the pipeline; if possible, tested section of the

pipeline should be isolated from human access before starting hydrotest. After completion

of the hydrotest, unfilled top sections of the couplings should immediately be filled with

approved material.

1.4.2.2 Pressure Testing.

Below outlined method can be followed:

Increase the pressure to 3 5 bar.

Keep the pipeline under this pressure for 12 hours for stabilization.

Shut off all air valves after ensuring that all air is expelled from the pipeline.

After stabilization period, increase the pressure by 1 bar every 10 minutes.

Perform continuous monitoring of the pipeline section especially the partially

exposed joints

Continue to increase the pressure (as explained above) until the applied pressure is

1.5 times of the nominal operation pressure of the pipeline. (Field hydrotest pressure

is defined as the 1,5 times of the nominal operation pipeline pressure)


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Ensure to measure the test pressure referenced to the lowest point of the pipeline

section.

1.4.2.3 Allowable leakage

Allowable leakage will be established as per project specifications and applicable standards

(e.g. BS 8010: Part 2.5)

1.4.2.4 Water Discharge

There are a number of options for disposal of hydrotest water. These include disposal to

temporary break tanks and/or holding ponds. The purpose of the break tanks is to dissipate

energy. They will also assist in the reduction of suspended solids while holding ponds allow

time for Chemicals Degradation. The holding pond will be constructed to enable

evaporation, infiltration through a soak away or to allow water re-use dependent on site-specific circumstances.

As feasible Test water for GRP pipeline will be discharged back into the water In Take. Exit

water analyses will be conducted prior to any discharge to the environment.

1.4.3 Carbon Steel Pipeline

1.4.3.1 Cleaning and Gauging

Each pipe length has been cleaned and ensured free of obstructions before and during the

welding of the strings for lowering; additionally all the pipe strings have been kept capped to

avoid any debris or animal to enter during the construction activities.

Since CS pipelines in ENI-MOD Project have short lengths, the final cleaning and gauging

could be performed from their start up to their end, along the entire pipeline. Bi-directional

scrapers will be launched propelled with compressed air. Scrapers could be provided with

steel wire brush to increase the removal of mill scale and debris left inside the pipeline.

Cleaning and Gauging with scrapers propelled by air mainly removes bulk construction

debris, such as skids, rocks, tools, welding rods, rags etc. Dust and fine sand are not easily

removed by scrapers run with air irrespective of distances. This will be removed by the

water flushing during the filling and during the final dewatering.

Gauging will be performed in a separate run. If major construction related debris, arrive from

the pipeline in front of the cleaning scraper run at the end of the initial cleaning operation


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then, the subsequent gauging plate scraper run shall be accompanied with a brush scraper

to ensure the pipeline section is free of debris,

Gauging plate diameter shall be according with Project Standards & Specifications. The

gauging plate will be verified in the presence of Company Representative for scratches or

bends. If the gauging plate is received in a damaged condition, the gauging scraper shall be

rerun until the obstruction is found and repaired. Minor scraping or nicks in the gauge plate

are considered acceptable.

1.4.3.2 Electronic Caliper Survey

If required an electronic caliper survey from Company approved Caliper subcontractor.

Electronic Caliper Survey will be performed prior to the pipeline hydrotesting. Contractor will

conduct the work in the following sequence:

Pressurize the pipeline between launcher and receiver to have a backpressure between 45

to 50 psig (3 to 3.5 barg)

Run the caliper tool along the pipeline maintaining the correct compressed air injection from

behind and the back pressure in front in order to keep the speed run at around 3 to 5 km/hr

avoiding surges.

Upon the tool arrival the data collected will be down loaded and verification will be made to

ensure that the pipeline has been completely surveyed. This operation will be done at the

receiver site. In case are data missing in the run then another run shall be performed.

Results shall be evaluated and a preliminary written report will be submitted to the Client,

on-site, within 3 days of the completion of survey. The preliminary report will identify all

locations having anomalies outside of the acceptance criteria. Contractor shall immediately

verbally advise Client of all recorded abnormalities. This report will confirm that data has

been collected and will identify any major features found in the first pass of the data.

1.4.3.3 Water filling flushing and venting

A temporary 4 line from the 28 GRP pipelines to the CS Pipelines at WFTP will be

constructed to supply the water required for the filling and flushing of the CS Pipelines.

At this stage the required water treatment will be applied to the fill water taken from the

GRP pipelines.


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Sequence will be as follows:

Water filling and flushing will be assisted with minimum one bidirectional scraper launched

from WFTP with proper air back pressure for scraper run control.

Pump 100 linear meters of water in front of the filling scraper. This water will provideadditional control, sealant and lubrication to the flushing and filling scraper, while help to

remove the small particles (sand & dust) left after the cleaning and gauging activity.

Launch the scraper by pumping the filling water behind. If there is a second filling scraper

planned to be launched (depends of pipeline length, profile and piping accessories) then

stop pumping once the first scraper has travelled around 100 Linear Meters and proceed to

launch the second filling scraper by pumping water until the scraper(s) reaches the pipeline

section end. Upon all the scrapers are launched the required water treatment shall

commence.

A temporary discharge line directed to a Company approved tank/pound will be used to

control the air back pressure during the water flushing and filling and to receive in control

manner the filling scraper(s). Initial and final air back pressure must be calculated based on

the pipeline elevations.

Once the scraper(s) is received, and therefore the flushing and water filling are completed,

the raise the pipeline pressure to 10% of the test pressure by the filling pump and allow for

a minimum of 24 hours for temperature stabilization.

1.4.3.4 Pressurization and Pressure Test.

Upon temperature stabilization of the hydro test water the pressure will be raised to the

strength test pressure in gradually and steady way in steps no greater than one fifth of the

strength test pressure after 50% of the pressure is reached. In between these steps of

pressure rising allow for a minimum holding time of 10 minutes.

During the hydrostatic pressure testing the pressure and pipe/water temperature must be

continuously monitored and recorded with the approved testing equipment as per project

specifications.

Two Hours of Strength test will be followed by the pipeline depressurization to 95% of the

strength test pressure and then, the 24 hours of tightness test will continue. Appropriate,

safety devices, procedures and monitoring to maintain the strength test pressure in between


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the safe limits must be implemented and volumes of water removed or injected must be

recorded. During tightness test the addition or removal of water is not allowed.

Pressure test shall demonstrate to Client satisfaction that there are no leaks in the pipeline.

Should the final tightness test pressure be lower than the initial pressure, Subcontractormust determine if this pressure variation is resulting from temperature change in the

pipeline section during the test period. Pressure changes shall be calculated and supported

by the formulas previously approved by Company.

Upon approval of the tightness test, the pressure will be reduced to a minimum of 30-50

psig at the highest pipeline elevation.

1.4.3.5 Pipeline Dewatering and Hydrotest water disposal.

Upon successful completion of pressure testing, the Section will be depressurized, the

temporary test headers and blinds removed, and reinstatement with final tie-ins performed.

Any disposal of hydrostatic test water shall be done to the designated disposal / evaporation

pond or tank through temporary discharge line. Displacement of the water from the pipeline

section will be performed using dewatering pigs driven by compressed air.

As possible the use of water inhibition or chemical additives will be avoided to reduce the

environment impact to just sediment and suspended debris. Water will be discharged into

sedimentation pools or temporary holding tanks, before discharge into the environment. If

the addition of chemicals and additives to the test water then they will be selected as much

as possible to be environment friendly and the holding time in the discharge ponds must be

longer to reduce the chemicals reaction. Subcontractor will ensure compliance with current

environmental regulations and permits obtained for the project, which are in force in the

relevant areas of hydrotest water discharge.

1.4.3.6 Pipeline Drying and Lay-up

Drying of the pipeline will be carried out immediately following dewatering. Various

techniques can be used, including:

- Chemical swabbing;

- Vacuum drying.

- Air drying; and

- Nitrogen Drying


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The dryness level and drying technique followed by the required Lay-up will be addressed in

detail during the development of the specific procedures for the Project in compliant with the

Specifications and Codes approved by Company.


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ANNEX 1 - SCHEMATIC OF THE PIPELINES


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ANNEX 2 - SPECIFIC EQUIPMENT

Description Minimun Specifications (desirable) Qty Units

Pick-up 4x4 / double cabin 2 Each

BoomTruck 6x6 - 5 Tons 2 Each

Water Tanker 12 M3 2 EachStorage Tank 12 M3 2 Each

Compressor 16,000 Lts/min 12 Bar 3 Each

Compressor 8,000 Lts/Min 7 Bar 1 Each

Torquing Wrench 700 Bar 2 Each

Torquing hydraulic Air Driven

Pump 700 Bar 2 Each

Water Pump 150 M3/Hr 20 Bar 2 Each

Selfcleaning Filter 200 M3/Hr X 100 m Mesh 10 Bar 2 Each

Pressure Pump 100 Lts/Min 30-40 Bar 2 Each

Mobile Test CabinW/ Instrumentation (gauges, Recorder P-T,

etc) 2 Set

Dead Weight Tester 50 Bar 2 Each

Generator 25 Watts 3 Phases 380/240 v 2 Each

Lighting Tower/Gen 10 wats 4 Lights 3 Each

Scrapers (Pigs)

Bi-Di 4 Rubber Discs/ SteelBody 20" 5 Each

Bi-Di 4 Rubber Discs/ SteelBody 24" 3 Each

Bi-Di Soft Rubber Type 24" 7 Each

Bi-Di Soft Rubber Type 28" 10 Each

Foam Mediun Density 20" 4 Each

Foam Light Density 20" 8 Each





Gauge Plate 20" 3 Each

Gauge Plate 24" 2 Each

Spare 4 Discs Sealant (Set) 20" 2 Set

Spare 4 Discs Sealant (Set) 24" 2 Set

Pig Locator + Receiver 6 Set

Hand Tools Spanner all Sizes 4 Set

Documents

GRP Hydrotesting 01.docx