Statoil has not used this type of technology on supply vessels before but M-I SWACO has used the technology on its own vessels. This is the first time that the Schlumberger company M-I SWACO has commercialised the technology.
The solution comprises an automatic system which means that personnel avoid having to enter the tanks in order to clean them. Wash water and soap are also recycled so that it is only the actual waste washed out of the tank that has to be delivered for further processing.
This is what the M-I SWACO tank cleaning module looks like.
The supply vessels transport chemicals in tanks below deck. When the tanks are emptied offshore they must be cleaned before being used for other assignments.
Tank cleaning is often carried out with the vessels' own tank cleaning plant, although manual tank cleaning has also been necessary on some occasions.
Manual tank cleaning is carried out by emptying the tanks of residual volume before personnel enter them, erect scaffolding and rinse with water and chemical cleaning agents.
Manual tank cleaning normally generates a high volume of waste and a typical clean can involve 10–15 cubic metres per assignment.
"By cleaning the water in the same operation, the volume of waste is reduced significantly," says Stangeland.
The new system will fit onto a lorry, and once the system has replaced manual cleaning, vessels will spend much less unproductive time while docked in connection with tank cleaning.
Statoil is constantly searching for new areas that can reduce the environmental footprint the company generates. All the supply vessel newbuilds that have entered long-term contracts in the portfolio in the past two years have been modified to use shore power.
They will also be equipped with a marine generator that can be used instead of the main engine, when the vessel is docked.