WWW.ENERGY-FOCUS.COM Issue 8 2007

Pipeline coatings are critical to thelong term performance of a pipelineand have evolved over the years to

match construction and operatingconditions. As the ‘easy to get’ oil and gasbecomes depleted, the operators lookfurther afield for major finds. These energyfields have therefore become more remoteand the reservoirs are often much deeper.This means that the conditions to constructa pipeline are more challenging than beforeand the oil or gas is flowing at much highertemperatures and pressures.

To meet the demands of these conditions,the engineering behind pipelines has becomemore sophisticated, higher strength steels arebeing used and higher performance pipelinecoatings are required. One of these coatingsincludes 3-layer polypropylene (3LPP),which consists of a fusion bonded epoxy(FBE) primer, a polypropylene adhesive anda polypropylene top coat. The coating type issimilar to 3-layer polyethylene exceptthat polypropylene is more temperatureresistant than high density polyethylene,which becomes a major factor on pipelinesoperating at temperatures greater than 80ºC.These types of pipelines may be typicalof flow or gathering lines in an oilfieldwhere the resource is drawn from deepreservoirs and flows at very hightemperatures (100ºC-140ºC).

Another reason for specifyingpolypropylene is its superior hardness andabrasion resistance. This can be importantfor use in remote oilfields, where pipehandling will traverse rocky terrain,

for directional drilling applications or foroffshore pipelines where a damage-freecoating will save time and money duringpipeline construction.

The available options for fieldjoint systems compatible with 3LPP andeconomical to install had been limited inthe past. This became a factor in whether ornot a specifier would choose the coatingtype. Over the past five years, however,several field-friendly systems have beendeveloped, but how does a specifier choosewhich one to use?

As a basic design principle, it ispreferable to have a field joint that closelymirrors the mainline coating and providesan equal level of specified performance.However, field joints have differentrequirements than mainline coatings. Oneof the requirements of a mainline coating isto withstand the rigours of transportation tothe right-of-way or lay barge, whereas thefield joint is applied just before the pipelineis laid. Conversely, the field joint is appliedunder variable field conditions, whereas amainline coating is applied in the controlledconditions of a manufacturing plant.Therefore, product selection becomes afunction of economics, the true pipelinein-service operating conditions and thechallenges of field application.

Canusa-CPS has been a pioneer in thedevelopment of cross-linked polyethyleneheat-shrinkable field joint systems and wasable to develop a heat-shrinkable sleevebased on polypropylene rather than thetraditional polyethylene. To that end,

Canusa’s GTS-PP polypropylene heat-shrinkable sleeve has quickly become anindustry standard for use on 3LPP coatedpipelines and for onshore and offshoreapplications.

As a case history, Canusa recentlycompleted the In Amenas pipeline in Algeria.

The qualification and installation steps forCanusa’s GTS-PP product used on theIn Amenas project included the followingsteps, some of which were done in parallel:

• salt contamination test;• surface preparation by abrasive blasting;• surface profile measurement;• surface cleanliness check;• positional markings for heat-

shrinkable sleeve;• mixing of liquid epoxy primer;• initial joint pre-heat (prior

to epoxy application);• liquid epoxy primer application;• wet film thickness measurement;• pre-heat to force cure epoxy;• sleeve positioning and heat shield

placement;• sleeve installation and recovery

with propane torches;• inspection;• adhesion tests after cooling.

Key elements in the successful completion ofa field joint coating project include:

Product selection Consult with the fieldjoint coating manufacturer or a consultantwho is knowledgeable about available gradesof products on the market.

Product pre-qualification Once specified,the manufacturer of the field joint productsshould pre-qualify the products and providethird party test reports that the product willmeet its stated performance level.

Contractor qualification and trainingEnsure that the contractor is fully trained inthe installation of the product. Crediblemanufacturers will have the resourcesto send field service people to a job site totrain the crew and qualify the equipmentto be used.

Ongoing inspection Confirmation thatthe proper level of surface preparationis being done plus a simple field adhesiontest will tell if the product has beeninstalled properly.

As with any field-installed constructionproduct, field-joint protection systems arereliant on proper selection and installationquality to attain optimum performance.For heat-shrinkable sleeves, ensure that aproven system is specified, manufacturerinstallation recommendations are followedand ongoing inspection is done to ensurequality of installation. •

3-layer polypropylene pipelinecoatings and field joints

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ROBERT BUCHANAN & PASCAL LAFERRIERE, CANUSA-CPS, TORONTO, CANADA

Oil & Gas

CAN A ED AD EF:L EIC 8 7/3/07 14:33 P 78

Algeria

M

In Amenas

Oil Field

Project Success Story

Uniqueness

Hurdles to Secure the Project

Located in the southeastern part of Algeria, the pipeline constructed as partof the In Amenas oilfield development used a polypropylene anti-corrosioncoating due to a very high operating temperature. After extensive projectqualification trials, Canusa-CPS’ GTS-PP polypropylene sleeve was selectedas the optimal polypropylene coating for the field joints on the project.GTS-PP was chosen for its excellent performance as a high temperaturepolypropylene corrosion coating, as well as its simple installation, whencompared to other polypropylene field joint coating systems.

With its polypropylene materials, the patented GTS-PP system offersexcellent high temperature corrosion and mechanical protection, meetingthe highest industry standards for high temperature polypropylene coatings.GTS-PP is applied at lower temperatures and requires less complexequipment and specialised labour than other systems that providecomparable polypropylene protection, increasing productivity and loweringproject costs. The product is also shipped pre-cut to site, reducing handling,positioning and installation time, making it ideal for installation inchallenging field conditions.

The design engineers for the In Amenas project had very strict requirementsfor the 3LPP field joint coating to be used on the project. Extensivequalification trials were required for approval of the coating system toensure equivalent performance to the factory applied 3LPP coating. Todemonstrate compliance with these stringent requirements, Canusa-CPSmobilized its strong field service team and held qualification trials at itsfacility in the United Kingdom and at the project site in Algeria. After fullqualification of the GTS-PP system, comprehensive operator training andproject start-up assistance was provided by Canusa-CPS in Algeria to ensurea successful project execution.

Proven Performance • Global Experience

www.canusacps.comCanusa-CPS is registered to ISO 9001:2000.

In Amenas

HighlightsProject:

Market:

Country:

Product:

Length:

Pipe Diameter:

Pipe Coating:

Year:

In Amenas

Oil & Gas

Algeria

GTS-PP

10,000 joints

10” – 24”

3LPP

2006

Canusa-CPS Case History:

For more information contact your local Canusa-CPS representative.

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