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Platform supply vessel sailing at sea, illustrating marine engine lubrication and oil filtration performance.

Eliminated sludge and restored engine cleanliness on a platform supply vessel

Replacing centrifugal separators with offline fine filtration reduced insolubles, cleaned the engine internally and lowered operating costs.

Case study written by Lauritz Lyngsnes, Øwre-Johnsen AS, Norway

Application Snapshot

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Industry:

Marine

Globe icon representing geographic location or country.
Country:

Norway

Oil droplet icon representing oil type or lubrication fluid.
Oil type:

Main engine lube oil

Executive summary

A platform supply vessel operating with Wärtsilä generator engines experienced persistently high levels of insolubles in the lube oil, resulting in heavy internal engine contamination. Despite the use of centrifugal separators, high oil temperatures and multiple optimisation attempts, the problem could not be resolved and was reported to several OEMs without success.


By replacing the separator with a CJC® Fine Filter, insoluble content was rapidly reduced and engine cleanliness visibly improved. The solution eliminated sludge formation, simplified maintenance and reduced oil consumption, delivering both operational and environmental benefits.

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Oil droplet icon representing restored oil cleanliness and reduced insolubles in engine oil.

Restored oil cleanliness

Insolubles reduced from up to 1.0% wt to 0.1% wt after installation.

Dollar symbol icon representing lower operating costs through reduced oil use and maintenance.

Lower operating costs

Reduced oil consumption, spare parts use and maintenance effort.

Oil degradation icon representing elimination of sludge deposits inside the engine.

Eliminated sludge formation

Black sludge deposits inside the engine began disappearing within weeks.

CO₂ cloud icon representing reduced oil losses and lower carbon emissions.

Reduced environmental impact

Lower sludge volumes, reduced oil losses and reduced CO₂ emissions.

Internal view of a marine engine component with visible oil contamination and deposits.

Client brief

The platform supply vessel M/S Bourbon Mistral, operated by Bourbon Offshore Norway, experienced ongoing lube oil contamination issues across its Wärtsilä main generator engines.

Oil samples showing clean oil and contaminated engine oil with high insolubles.

Challenge

From new, the engines suffered from high insolubles levels and heavy internal contamination. Centrifugal separators were operated continuously at high oil temperatures and modified with customised gravity discs, yet without resolving the issue. Multiple OEMs were consulted, but no effective solution was found.

CJC® Fine Filter unit designed for offline filtration of marine engine lube oil.

Solution

A CJC® Fine Filter HDU 27/81 P E2H1, equipped with a P-19-6 pump and CJC® Filter Inserts A 27/27, was installed on one main engine. The separator was disconnected and replaced entirely by the offline filtration solution, designed to operate reliably at high oil temperatures.

Internal view of a marine engine component showing restored cleanliness after offline fine filtration.

Restoring engine cleanliness with offline fine filtration

After installation of the CJC® Fine Filter, the system operated continuously on the main engine. After 18 days and 70 engine running hours, an oil sample was sent for independent analysis.


The results confirmed a rapid reduction in insolubles, while physical inspection showed that accumulated sludge inside the engine had already started to disappear.

Measurable results and operational impact

The installation of the CJC® Fine Filter reduced insolubles in the lube oil from between 0.7–1.0% wt to just 0.1% wt, restoring oil condition and visibly improving internal engine cleanliness. Sludge problems were eliminated, maintenance became simpler and less frequent, and oil consumption was reduced.


By removing the centrifugal separators, the vessel also reduced sludge handling, spare-part usage and associated operating costs, while achieving a positive environmental effect through reduced waste and emissions.





“I have good experience with CJC® Oil Filters and was not surprised to see the effect. We are now installing similar filters on the remaining engines and on the sister vessel.”


– Torbjørn Gravdal, Technical Inspector, Bourbon Offshore Norway

Chart showing reduction in insolubles and soot levels in engine lube oil after installation of CJC® filtration.

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