The consultant started work on the project in February, in partnership with DNS and Zero Waste Scotland. One aim was to identify removal solutions that would obviate the need for diver interventions during the lift procedure, potentially improving safety and reducing operational costs.
Nigel Jenkins, DNS chief executive, said: “This project was implemented in direct response to our operator member requests… Mattress removal can add significant costs to decommissioning projects, hence we are keen to establish a variety of solutions to further drive efficiency.”
Jee’s suggestions for re-use of the mattress concrete include tidal lagoon structures; construction of artificial reefs to encourage new sea life; and laying road foundations, all potentially reducing the need for new concrete.
Subsea engineer Adam Smith said the research would form a basis for economic and environmental assessment of mattress conditions and the options for removal and re-use going forward.
“We also helped to identify the criteria required to determine whether subsea mattresses should be removed or left in situ, the main consideration being the safety of the subsea divers and the environmental impact.”