THE WAYLINING

W ith the expansion of steam assisted gravity drainage (SAGD) and hydraulic fracturing (fracking)

production technology in North America over the last 15 - 20 years, Canada and the US are now squarely positioned amongst the world’s top producers of bitumen and natural gas. Although the industry has experienced significant technological advances in these processes, traditional lining systems used in the industry to protect equipment assets are not keeping up with the higher standards of protection required by these production developments. As a result, owners and operators are turning to their coating manufacturing vendor partners for new technology solutions that will help ensure their facility structures and

infrastructures continue to keep up with global production and environmental compliance demands.

Assessing the damageThe oil and gas industry has historically relied on linings systems formulated from conventional epoxy phenolics, fusion bonded epoxies, and novolac epoxies. These formulations have provided fairly reliable protection over the years; however as SAGD and fracking production processes continue to evolve, a troubling pattern of systems failures is also emerging:

) Ultra-high heat steam and harsh chemical additives are both utilised in the SAGD and fracking processes to help loosen the thick viscous bitumen found in underground oilsands and natural gas deposits trapped inside tight shale and rock

Advanced oil

and gas production

processes raise the bar

on lining performance and

compliance requirements,

explain Stephen Streich

and Darryl Corbin,

AkzoNobel, USA.

formations. The continuous thermal cycling of extreme high heat, followed by periods of cool down, combined with chemical immersion and exposure, can severely compromise a lining’s integrity and corrode the carbon steel substrate underneath, causing ruptures.

) Pipeline exteriors must have the durability to withstand the abrasive elements of being buried below ground as well as high temperature cathodic protection. Backfilling operations and constant movement in the earth can cause rocks and boulders to shift and scrape against the pipe causing cracks in the coating material, which expose the steel substrate to potentially corrosive soil. Likewise, pipeline interiors can also crack when exposed to continuous radiating heat, chemical attacks, and pressure of the water solution flowing through the pipeline.

) Onsite storage tanks and process vessels used in separating the oil from the abrasive, chemically-laden water solutions are especially susceptible to interior corrosion and leakage, as are those used to clean and treat the toxic water after use.

Tank leakage can result in a complete halt in operation, often costing millions in lost revenues while repairs are being made.

) Without proper protection, rapid deterioration of pipeline and tank interior and exterior linings can have a devastating impact on the environment through contamination. Health and safety concerns associated with these repairs and re-linings must also be addressed each and every time maintenance and repair operations are performed.

Finding the right protectionIn order to properly identify and specify an appropriate lining system for use in new pipeline or tank construction, maintenance or repair projects, the owner or operator must first have a thorough understanding of the operating conditions as well as their ultimate objectives for installation of the lining system.

They must provide a detailed list of project operating conditions and the owner’s expectations to the specifier, who will in turn provide that information to the coating manufacturer. That list will include items required to maintain proper application, such as:

) Variable operating temperatures.

) Exact chemical concentrations used and duration of exposure.

) Abrasion and impact exposures, especially in below ground pipeline installations.

) Whether or not the pipeline or tank must be insulated.

) Application capabilities of the contractor.

) Climate conditions according to location (i.e. a dry, typically warmer desert biome, or extreme low temperature tundra biome such as the North Slope in Alaska).

) Environmental conditions.

These factors will help the linings manufacturer recommend and/or develop the appropriate lining technology to meet all of these requirements and ensure compliance.

In addition, effective linings systems require the optimisation of other material ingredients that might affect things like wetting and levelling properties, flexibility, cure times, pot life and VOC emissions. Together, these elements can make a big impact on critical performance issues such as temperature and chemical resistance, abrasion resistance, adhesion characteristics, application properties and regulatory compliance. Most importantly, these lining formulations must undergo extensive laboratory and field testing to demonstrate and prove effectiveness during actual in-service evaluation.

In an effort to address specific performance and compliance issues associated with SAGD and fracking production processes, AkzoNobel developed a proprietary high build, low volatile compound (VOC) lining in 2004. That technology known as Enviroline 405HT, has been repeatedly and rigorously tested for more than a decade and has proven its effectiveness in field applications across the globe, with successful results validating its superior performance in high temperature and corrosive environments.

Figure 1. The unique glass fibre and flake reinforced technology offers improved durability and corrosion protection, with efficient application to both interior and exterior of pipes.

Figure 2. Pipeline exteriors must be able to withstand the abrasive elements of backfilling operations, being buried below ground with shifting rocks and boulders, and high temperature cathodic exposure. Cracks in the coating material can expose the steel substrate to potentially corrosive soil.

REPRINTED FROM WORLD PIPELINES / / 2016

Building upon that same technology to raise the bar on environmental compliance and improved performance in North American and global applications, AkzoNobel introduced Enviroline 405HTR into the oil and gas industry in 2015. This product improvement is in line with the company’s core value of sustainability.

A leader in global sustainability initiatives, the coatings manufacturer celebrated its fourth consecutive year with a number one ranking on the Dow Jones Sustainability Index within the Materials Industry group.

The unique glass fibre and flake reinforced technology offers added durability and protection within a broad range of environments and temperatures – from continuous immersion in chemicals including crude oil and hydrocarbon water mixtures of up to 300˚F (149˚C) – to applications with temperatures as low as 50˚F (10˚C). Highly durable and flexible, the new formulation provides greater abrasion resistance and high temperature cathodic protection for underground pipeline applications and can be efficiently applied in both the interiors and exteriors of the pipe. The ultra-fast cure times enables piping to be handled faster and provides for quicker throughput and increased production. In addition, the improved substrate wetting and levelling properties reduce the likelihood of holidays and lining defects, which decreases the overall time required to identify and repair lining imperfections. For a pipe manufacturer, this translates to a speedier inspection process, operational throughput, and greater efficiency.

These same features allow storage and process vessels to return to service in as little as 14 hours after coating to minimise production downtime. Environmental impact is further reduced through the ultra-low VOC, single coat high build application (20 - 60 mm), which will help extend the service life of structures and infrastructures and provide significant savings in labour and materials costs.

Maximising lining effectivenessProper surface preparation of steel substrates is critical for achieving optimal lining performance – especially in high temperature immersion conditions. Surfaces must be cleaned and abrasive blasted to the SSPC SP-5 White Metal Blast Cleaning standard with no detectable soluble salt limits for better resistance to corrosive cell formation and coating adhesion.

Provided that the manufacturer’s product test data meets the performance requirements of a given project and proper surface preparation has been completed, other factors such as trained technical service can improve application outcomes. For example, AkzoNobel has a dedicated team of highly trained technical service managers that provide ongoing customer support throughout the project, as well as a web-based project and facility asset management program called Interplan that can manage any coating/lining project size from initial installation to decommissioning. This type of support goes a long way in helping owners and maintenance engineers identify the most urgent areas of repair and relining, determine the projected cost of the lining installation, estimated production downtime, and the schedule of facility maintenance long-term.

Aligning with the futureSome oil and gas experts question whether or not these advanced production processes will have ultimate cost and environmental viability in the future, yet recent data indicates that with better cost-control practices, a clearly defined project scope during planning to avoid unanticipated events and ongoing technical process improvements will all play an important role in these production processes, becoming established players in large-scale commercial projects long-term. Indeed, SAGD alone is already being hailed as one of the least invasive production techniques with lower environmental impact over conventional open-pit oilsands operations – and with the highest recovery rate of up to 80%.

Owners staking a claim in this production technology will continue to strive for operational excellence, better regulatory compliance and improved cost-efficiencies. Being aligned with coating manufacturing vendor partners who have shared innovative vision, a commitment to sustainable practices that enhance the quality of human lives and the planet, and who continually seek ways to improve customer productivity and profitability will help them realise those goals now – and well into the future.

Table 1. Testing procedures used to evaluate external buried pipeline coatings for suitability

Test Acceptance criteria

Test type 405HTR results

Film thickness Manufacturers

recommendations

SSPC-PA2 20 - 60 mm

DFT

Shore D

hardness

Manufacturers

recommendations

Clause 12.1 of

the standard

80+

28 day cathodic

disbondment at

maximum rate

10 mm maximum

radius

CSA Z245.20,

clause 12.8

5.2 mm at

203˚F (95˚C)

1.5J impact

resistance

No holiday CSA Z245.20,

clause 12.12

Pass

3.0J impact

resistance

No holiday CSA Z245.20,

clause 12.12

Pass

*Testing procedures carried out via CAN/CSA Z245.30-14, coating

type FC1 requirements: liquid-applied or fusion bond epoxy (FBE)

with glass transition temperature of up to 239˚F (115˚C).

Table 2. Additional testing conducted

Test Test type 405HTR results

Adhesion ASTM D4541 Standard

test method of pull-off

strength of coatings

using portable adhesion

testers

Steel: >1500 psi, 11 MPa

Abrasion

resistance

ASTM D4060 CS17 –

wheel 1 kg load, 1000

cycles

65 mg

Elevated

temperature

ASTM D5499 method A 400˚F (204˚C) continuous

exposure

Flexibility

ASTM D5043 standard

test method for plane-

strain fracture touchness

and strain energy

release rate for plastic

materials

Average flexural strength

54 MPa, average flexural

strain 1.55%, average

flexural modulus 4324

MPa

REPRINTED FROM WORLD PIPELINES / / 2016 EX