Region: North Sea
Content Types: Report
Date: Apr, 2022

DOF Subsea

DOF Subsea has attained a 99% rate for the combined recycling and repurposing of recovered materials on its decommissioning project for Repsol Sinopec Resources UK.

The company provides engineering, preparation, removal and disposal (EPRD) services at the Buchan and Hannay fields in the Central North Sea.

The offshore works were carried out for over 74 days, using Skandi Acergy and Skandi Skansen, and saw the recovery of 135 concrete mattresses weighing approximately 800 tonnes, more than 12km of rigid pipelines, SSIV/PLEM Structures, 15.5km of flexibles and umbilicals, spoolpieces, and around 1,500 grout bags 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 £350mn 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, they carried out EPRD services, including the 124 tonne Mid-Water Arch (MWA) – one of the largest structures ever decommissioned through Aberdeen Harbour.

DOF Subsea has built a decommissioning portfolio over the last decade, delivering more than 30 projects around the world for major operators.