By DARA BUTTERFIELD
Decom North Sea (DNS) the representative body for the decommissioning industry – has set up a partnership with Zero Waste Scotland (ZWS) and subsea engineering and training firm, Jee Ltd, to investigate efficient solutions for the recovery and re-use of concrete subsea ‘mattresses’.
Concrete mattresses provide pipelines, cables and umbilicals with protection from dropped objects, and add weight and stabilisation. Jee’s analysis will identify potential re-use applications for these ‘mattresses’ as well as highlighting guidance on best practice for recovery – where possible.
The project involves engaging with operators and suppliers across the oil and gas industry, with both DNS and Jee’s expert engineers conducting an economic and environmental assessment of the condition of the mattresses, and identifying the best techniques for their recovery.
Nigel Jenkins, Chief Executive, DNS said: “This project was implemented in direct response to our operator member requests.
“What to do with mattresses as part of an efficient decommissioning solution is an oft-discussed “thorny” issue. Leaving them in situ is not ordinarily an option, although we will revisit this.
“Mattresses were not specifically designed to be removed. Unfortunately, they can degrade underwater over time, leading to a complicated and costly removal process during decommissioning.”
Dean Kirby, Senior Engineer, Jee Ltd, said: “Millions of pounds are being spent on UKCS decommissioning each year, and this will continue for several decades. As with the majority of decommissioning projects, the recovery and disposal of subsea mattresses presents a significant obstacle and financial burden to operators and contractors globally.
“There is a need for a safe, quick and cost effective system for mattress removal, and at Jee we strive to identify and develop the best solutions for the industry.”