1. coatings&linings
coatings&linings
REPRINTED FROM World Pipelines FEBRUARY 2007 www.worldpipelines.com
P
ipelines are the primary means of transporting oil and natural gas today, whether it be from the well field location
to processing facilities, or supplying power to product producing outlets, or for long distance export of fuel to neigh-
bouring countries. When compared to tankers or road transport, pipelines have been considered as a safe, efficient
and cost-effective method of transportation.
However, as operators worldwide are striving to increase production to meet rising global energy demand, the
durability and reliability of pipelines becomes critical. Pipeline operators are therefore being asked to consider
safety, environmental and economic issues when designing a pipeline system.
Quantifying pipeline incidents
Pipelines today are operating at maximum design limits to produce maximum output, which can pose a threat to people and
the environment, if not managed carefully.
According to the National Physical Laboratory (NPL), the UK’s National Measurement Laboratory, it is pivotal that the oil
and gas industry ensures the provision of a continuous supply of its products to end users, whilst controlling the impact on
the environment and complying with ever more stringent safety guidelines. This is a view that was expressed by the UK’s Prime
Minister in an energy white paper in 2003 and one that continues to be expressed today, not only by the UK Government, but
by governments across the globe.
The US Coast Guard’s National Response Centre reported that there have been 19 214 oil pipeline accidents in the US
since 1991.
In 1994, a pipeline rupture in the Usinsk region of Russia lead to a spill of in excess of 100 000 tons of oil. Heavy
pollution threatened the ecosystem of the Pechora River basin.
Flow coating
solutions
David Bell andCraig Thomas, COPON
Pipelinings, E Wood Ltd, UK,
discuss preventative corrosion
technology for oil pipelines.

2. coatings&linings
REPRINTED FROM World Pipelines FEBRUARY 2007 www.worldpipelines.com
Since 1995, the amount of oil that is released into the
environment has increased each year. It is reported that, on
average, tens of thousands of gallons of oil were released
from pipelines approximately every other day throughout
the 1990s.
An Environmental Defense Fund (EDF) engineer testi-
fied at a recent pipeline safety hearing before the House
Commerce Committee’s Subcommittee on Energy and
Power that the average amount of oil released from a
pipeline spill in 1998 was over 45 000 gallons. EDF’s
analysis also details that the average volume of oil and
other hazardous liquids that are reported to be released
from pipelines annually is 6.3 million gallons: this is more
than half the amount of oil released from the Exxon Valdez
disaster.
After having carried out a 30 year performance review
(1971 - 2000) of Western European cross-country oil pipe-
lines, which, in 2002, comprised 30 800 km and transported
672 million m3
of crude oil and oil products, CONCAWE
reported that pipeline spillages have averaged 12.6 per
year and most are very small events - 5% accounting for
50% of the gross volume spilled. The frequency improved
from 1.2 to 0.25 spillages per 1000 km of pipeline.
The Financial Times reported in December 2006 that
US Senate leaders were about to pass a bill that would
strengthen pipeline design and safety, after it had gained
approval from the House of Representatives. The bill will
require pipeline operators to toughen safety inspection
regimes and will lead to the creation of a new federal
enforcement division. Mr James Oberstar, incoming head
of the House Transport Committee, commented: “The
legislation came on the heels of some serious pipeline
incidents...”. “The bill makes clear that there is going to be
a much larger scope of liability in terms of fines for pipeline
operators”, reinforced Mr Joshua Zive, an energy lawyer at
Bracewell and Giuliani.
The threat of corrosion
A common cause of spillages from oil pipeline systems is
corrosion attack.
It is of paramount importance that materials used in
pipeline construction and protection do not fail ‘uncontrolla-
bly’ in aggressive operating environments, leading to serious
environmental damage, as well as an inability on the part
of oil and gas operating companies to provide a continuous
supply of energy, as is demanded by their customers.
CONCAWE detailed that there were 20 occurrences of
internal corrosion and 90 incidences of external corrosion
resulting in a spillage from a Western European Pipeline
between 1971 and 2000. Corrosion accounted for 3.8
out of the annual average of 12.6 hydrocarbon spillages.
CONCAWE confirmed that kilometre for kilometre, crude oil
pipelines are three times more likely to suffer damage from
internal corrosion than product pipelines.
The pipeline industry has developed a range of technolo-
gies to reduce or even eliminate corrosion in oil pipelines.
New technologies are now available to improve on design
and to ensure long-term pipeline operation and integrity.
The Battelle Institute commented that it could be pos-
sible to save an estimated US$ 100 billion of the US’s
US$ 300 billion annual corrosion bill, if existing knowledge
and technology was applied to this problem.
The potential costs of loss of corrosion control in oil and
gas infrastructure are huge.
Based on the results of a DTI-sponsored survey in 2001
by the PRA, the estimated total cost of corrosion to the UK
Chemical and Petrochemical Sectors was approximately
£1730 million, which corresponds to 4.5% of industry
Figure 1. Copon EP2306 Series coated pipe awaiting onward shipment
to the pipeline construction site.

3. coatings&linings
REPRINTED FROM World Pipelines FEBRUARY 2007 www.worldpipelines.com
turnover. A possible 15% of this cost could be saved by the
better application of existing technology.
The PRA also estimated that corrosion adds over 8%
to capital expenditure and augments operating expenditure
by more than 11%. It was suggested that the total cost of
corrosion for the UK offshore sector amounted to at least
£250 million in 1988, corresponding to £0.16 per barrel
of oil equivalent. It is believed that the control of corrosion
in this sector has improved in recent years on account
of an improved understanding of corrosion mechanisms,
advances in corrosion inhibition, more effective inspec-
tion and advances in corrosion-resistant coatings. It was
claimed however that the average by which corrosion costs
could be reduced in the UK offshore sector was between
25 - 33%.
Finding a solution
The pipeline industry has several corrosion protection
solutions at its disposal. No review of corrosion protec-
tion technology for oil pipelines would be complete without
highlighting the specific benefits of the internal flow coating,
also known as a flow efficiency or flow enhancement coat-
ing, based on the experience of a coatings manufacturer
that has supplied product for over 140 000 km of pipelines
worldwide during a period spanning more than 45 years.
The concept of internally lining gas pipelines was devel-
oped in the 1950s, providing enhanced flow and corrosion
protection. International oil and gas companies such as
BP, Shell, Statoil, Transco, Exxon, Total, Reliance and CNPC
have now recognised the many benefits of internally coat-
ing gas pipelines, which has become industry practice. For
this application, Copon EP2306 Series was developed by
COPON Pipelinings, E Wood Ltd - a pioneer of internal flow
coating technology.
By the application of a two-component epoxy flow effi-
ciency coating, the internal surface roughness of the pipe is
sealed against corrosion attack during storage and commis-
sioning and the smooth Teflon-like finish provides reduced
pressure drop in operation and thus enhanced flow, leading
to cost savings.
Based on this internal lining technology, COPON
Pipelinings developed an internal flow coating that would
meet the exacting requirements and service conditions of
oil pipelines.
The lining system is based on a two-component epoxy,
which has been formulated using advanced organic
chemistry and fillers in order to provide the flow effi-
ciency coating with many unique properties, in particular
superior corrosion protection against the changing serv-
ice conditions throughout the length and service of oil
pipelines.
For internal corrosion to occur in oil pipelines, water
must be present. Analysis of the fluids, solids and gas will
also help to narrow down the possible corrosion mecha-
nisms. However, in most cases, internal corrosion is caused
by more than one mechanism.
Figure 2.
Steel pipe coated
with Copon EP2306
Series creating a
smooth, low friction
internal surface -
sealed against corro-
sion attack.

4. coatings&linings
REPRINTED FROM World Pipelines FEBRUARY 2007 www.worldpipelines.com
MIC
In particular, Microbiologically Influenced Corrosion (MIC)
has been quoted as being the primary cause of recent pipe-
line failures, resulting in oil spillages. It has been reported
that MIC was a contributing factor to the disruption of an oil
pipeline system in Alaska.
It was detailed in the pipeline integrity paper presented
at the ICGTI conference in 2003 that MIC comprises not
only the etching from the production of organic acids, but
can contribute to galvanic cells, oxygen or sulfide concen-
tration cells, stress corrosion cracking and/or hydrogen
embrittlement. The build-up of scale and deposits within the
pipeline can allow sites for bacteria to grow and concentra-
tion cells to occur, the most aggressive being the production
of hydrogen sulfide, a highly corrosive substance. Bacteria
can eat through the carbon steel pipes, leading to oil spills
and leakages.
Corrosion of metals by micro-organisms is a major prob-
lem on a global scale. Walsh et al. (1993) estimated the
cost of MIC damage at US$ 30 - 50 billion per year in the
US alone. Costerton and Boivin (1991) also estimated that
the cost of MIC damage as a result of Sulfate Reducing
Bacteria (SRB) alone to production, transport, and storage
of oil could amount to about one hundred million dollars
in the US annually. This figure does not include the costs
associated with lost oil and environmental clean-up.
It has been estimated that MIC in the natural gas indus-
try causes 15 - 30% of corrosion-related pipeline failures.
In the US, industrial companies spend US$ 1.2 billion on
biocidal chemicals to fight MIC every year. These treatments
are not only expensive, but they can also have a harmful
effect on the environment. A flow efficiency coating has
been developed by COPON Pipelinings to minimise MIC.
Application of the internal flow coating is carried out in
a pipe coating plant. The internal surface of the pipe is pre-
pared by a grit-blasting process followed by application of
the liquid pipe lining system. Cleaning the internal surface
and applying the flow efficiency coating is a preventative
measure against MIC.
Deposits in a pipeline can lead to numerous operational
problems, ranging from decreased flow to corrosion prob-
lems. The concern of corrosion engineers is the various
forms of corrosion associated with deposits. Through the
application of an internal flow coating, a clean and sealed
surface is created that reduces the potential for MIC.
By use of an internal flow coating, wax and hydrate
formation is dramatically reduced. A recent study con-
ducted by Herriot-Watt University concluded an internal flow
coating will inhibit the build up of wax and hydrates in oil
pipelines.
The problems of corrosion damage in oil pipelines and
how the use of an internal flow coating can help minimise
such problems and thereby extend the life of such pipelines
is highlighted in the case study of the BP Forties Line.
BP Forties case study
The original BP Forties Line was laid in 1973 - 74 between
the Forties Field in Block 21/10 of the North Sea’s UK
Sector to the Cruden Bay Terminal, near Peterhead,
Scotland. It was constructed out of 5L X65 steel with a
19 mm WT and measured 168 km x 32 in. It was the largest
offshore pipeline that could be built at that time and was
constructed for the development of the Forties Field.
A decision was made by BP to replace the uncoated
line, after it discovered corrosion on the first 20 - 30 km
of its line from the Forties C Platform to shore, follow-
ing detailed inspection carried out between 1988 - 89.
Corrosion had resulted in the pipeline’s Maximum Allowable
Operating Pressure (MAOP) being reduced from 129 barg to
103 barg. Corrosion had also caused damage to both lon-
gitudinal seam and girth welds, resulting in a reduction of
2 mm in the mean wall thickness. One defect was reported
to have reduced local wall thickness by more than 6 mm.
It was reported that corrosion damage had been attributed
to the presence of water containing carbon dioxide, which
in turn lead to the formation of carbonic acid. The nature
of the corroded surfaces had lead to the suggestion that,
apparently, the effects had been a major influence on the
location and rate of attack of corrosion. Temperature, the
characteristics of the produced waters, and the corrosion
products were also believed to have contributed to the
corrosion mechanisms in this offshore pipeline.
This decision to replace the original line with a new
36 in. diameter pipeline was based on the fact that third
party transportation was growing in importance as a reve-
nue-generating tool for the company. According to BP, inspec-
tion of the offshore Forties Pipeline “had indicated signs of
Figure 3. Uncoated steel pipe containing a large volume of millscale and corrosion products.

5. coatings&linings
REPRINTED FROM World Pipelines FEBRUARY 2007 www.worldpipelines.com
corrosion, which would have prevented the system operat-
ing economically as future demands increased.” In addition,
when the original line was commissioned in 1975, it was
not envisaged that the Forties line would transport crude oil
from other fields throughout the North Sea. It was said that
the new pipeline would increase capacity from 575 000 up
to between 900 000 to 1 150 000 bpd. Construction of the
replacement pipeline took place between 1990 - 1991. In
order to limit corrosion, particularly during the construction
and testing stages of the pipeline project, BP specified that
a “liquid epoxy primer [be] applied to the internal surface of
all linepipe”. This product was manufactured and supplied
by COPON Pipelinings, E Wood Ltd under its COPON EP2306
Series Internal Flow Coating brand.
The Forties Field, now owned by Apache, has become one
of the most productive fields in the North Sea, generating US
$1.3 billion of oil revenue on 24MMboe of production in 2005,
up 23% from 2004. Wood Mackenzie stated in 2004 that the
Forties Pipeline System (FPS) will remain a key asset in the UK
for BP with 900 000 bpd expected to flow though the pipeline
from over 40 UK sector fields and a number of Norwegian
fields. The Forties Line is still in operation today with no cor-
rosion problems since reported. Oil from the Buzzard Field in
the Central North Sea will be exported through FPS from late
2006 and build up to a peak production rate of 210 000 bpd
(in 2007).
Bibliography
BP Issues Guidance on Introducing Buzzard Crude to Forties Blend, BP
(08/03/2006).
BP’s Forties Pipeline System Wins Buzzard Contract, BP (05/12/2003).
Corrosion and Associated Costs in the UK Chemicals and
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Petrochemicals Sector, PRA (September 2001).
BURGESS, R W. and ROBINSON, I., Reducing the Risks of Solid
Deposition by using Internal Coating, 2003.
Corrosion and Associated Costs in the UK Offshore Sector, PRA
(September 2001).
Energy White Paper: Our Energy Future - Creating a Low Carbon
Economy, DTI (25/03/2003).
GRANT, J. and CALLAN, E., US targets Oil Pipeline Safety Problems,
FT.com (08/12/2006).
In Line Inspection prompts Forties’ Line Replacement, Oil & Gas
Journal. (17/06/1991).
Life Begins (Again) at Forties, Wood Mackenzie (16/01/2004).
Lifetime Management of Materials. Managing the Risks associated with
Corrosion in the Oil and Gas Industry, National Physical Laboratory
Website (Accessed on 08/01/2007).
LYONS, D., Western European Cross-Country Oil Pipelines 30-Year
Performance Statistics, CONCAWE (2002).
Microbiologically Influenced Corrosion (MIC), Institute for Corrosion
and Multiphase Technology (Ohio University) Website (Accessed on
02/01/2007).
PATIN, S., Accidents during Offshore the Offshore Oil and Gas
Development, Offshore-Environment.com Website (Accessed on
08/01/2007).
Pipeline Construction Booming in North Sea, Oil & Gas Journal
(20/08/1991).
Pipeline Integrity. ICGTI - USA. January 2003, CTGAS Website (Accessed
on 02/01/2007).
Pollution by Oil Pipeline Releases, Corrosion Doctors Website (Accessed
on 02/01/2007).
RHODES, A K., Export Crudes for the ‘90s Assay of Forties Stream
Updated, Oil & Gas Journal (15/07/1991).
RUSCHAU, G R. & AL-ANEZI, M. A., Oil and Gas Exploration and
Production. Corrosion and Prevention, (Date Unknown).
STEEL, W J M and INGLIS, R., BP Exploration. Forties Oil Line
Replacement overcomes Sandwave Challenge, Oil & Gas Journal
(06/05/1991).
UK North Sea - Overview, Apache Corporation Website (Accessed on
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Unsafe Pipelines, Pipeline Safety Foundation Website (Accessed
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