A case history using PRESERVAN 650
A major operator in the North Sea laid a 26 in. dry gas export
pipeline in preparation for commissioning a new oil and gas
production FPSO. The pipeline was constructed from carbon
steel with a 0.5 mm (20 mil.) corrosion allowance, and would
be filled with seawater for up to two years. The operator
had concerns over the preservation of the integrity of the
pipeline due to the corrosive nature of the seawater, and
asked Clariant Oil Services to recommend a suitable high
performing treatment that would combat the corrosion
mechanisms presented by the seawater for a duration of two
years.
Clariant Oil Services worked with the customer
requirements and recommended 500 ppm of
PRESERVAN 650 as the most appropriate product for
this application from the PRESERVAN range. PRESERVAN
650 is a combination product presented in a single
blend, which provides rapid scavenging of dissolved
oxygen plus controls the proliferation of micro-
organisms to reduce the risk of microbiologically-
influenced corrosion (MIC).
In order to provide treatment assurance, laboratory test
work was carried out to confirm the corrosion performance.
Coupon specimens from the actual pipeline material
including welds together with raw seawater from the pipeline
location were provided. All tests were performed at 4°C.
The results obtained over a three month exposure period
indicated that PRESERVAN 650 was able to reduce the
corrosion rate and that the integrity of the parent and weld
materials was not significantly compromised. The necessary
assurances were provided to the operator, and the pipeline
was commissioned as planned and is now in full operation.
Adopting a proactive approach
The PRESERVAN range of products has been designed to
fulfil all of the industry’s needs and for a wide range of
applications, including oil and gas export pipelines, topside
production facilities, subsea umbilical, risers and flowlines
(SURF), open or closed annuli and J-tubes, water injection
lines and vessels and storage tanks.
When it comes to corrosion mitigation and
maintaining the integrity of your pipelines and pressurised
equipment, adopting a proactive approach is best. By
taking the preemptive measure of treating your hydrotest
water with the right chemical solution, you will help
create a healthier pipeline from the start, which can
contribute to a healthier environment and may provide a
little peace of mind that could lead to a healthier you.
