Scour Prevention Mats
SPSL mats stabilise the seabed, protecting cables and pipelines from exposure and subsequent scour and freespan development in areas of shifting seabeds. The mats are applicable in the following situations:
- Protection for cable and pipelines crossings.
- Protection for cable and umbilical J-Tube exits.
- Maintaining required cable and pipeline burial depth in shifting seabeds.
- Preventing development of freespanning cable and pipeline sections.
- Freespan correction using mats in conjunction with infilling material such as tyre nets, aggregate, sandbags or gravel filter units. Scour Prevention Mats are laid on top of the cable or pipeline to prevent re-exposure through secondary scouring or sinking of infill material.
Cable and Pipeline Scour
When cables and pipelines are exposed on the seabed, scour acts to increase the extent and height of exposure above the seabed, developing freespanning sections. Freespanning sections expose the cable/pipeline to excessive wave and current forces.
- An estimated 9300km of subsea pipelines for transmission of oil and gas are projected to be installed between 2012 and 2017.
- A projected 11,000km of inter-array and export cables will be installed at offshore wind farms over the next ten years.
Cable repairs at offshore wind farms are associated with large costs, particularly where delays lead to a loss of income from power generation. Given that 80% of European offshore wind insurance claims are reported to be caused by cable problems, effective cable protection is a necessity not only to protect wind farm assets but also to minimise insurance premiums.