Decommissioning Project Hits 99% Recycle Rate
A decommissioning project carried out by DOF Subsea on behalf of Repsol Sinopec Resources UK in the Central North Sea has achieved a 99% rate for the combined recycling and repurposing of recovered materials.
DOF Subsea has completed a decommissioning project for Repsol Sinopec Resources UK to project manage and provide engineering, preparation, removal and disposal (EPRD) services at the Buchan and Hannay fields in the Central North Sea, achieving a 99% rate for the combined recycling and repurposing of recovered materials.
The offshore works were carried out over 74 days, using DOF's Skandi Acergy and Skandi Skansen vessels and saw the recovery of 135 concrete mattresses weighing approximately 800 tonnes, more than 12 km of rigid pipelines, subsea isolation valves and pipeline end manifold structures, 15.5 km of flexibles and umbilicals, spool pieces, and approximately 1,500 bags for grout and general debris.
The material was shipped to Aberdeen Harbour’s Clipper Quay for dispersal, with the recovered material dispatched for a wide variety of uses. A total of 15 concrete mattresses were repurposed into aggregate for use in the roads at the £350 million Aberdeen Harbour extension project. The plastic sheaths from the flexible risers and umbilicals were recycled by an approved supplier, and all metal was smelted.
This was the second decommissioning project carried out by DOF Subsea on behalf of Repsol Sinopec in the Buchan and Hannay fields. In 2019, the firm carried out EPRD services that included the 124-tonne Mid-Water Arch, one of the largest structures ever decommissioned through Aberdeen Harbour.