DOF Subsea recycles 99% of decommissioned oil rig

DOF Subsea says it has decommissioned both the Buchan and Hannay oil and gas field projects off the north coast of Scotland and achieved a 99% recycling and repurposing rate for all materials.

Operated by the Spanish/Chinese joint venture Repsol Sinopec, the offshore works were decommissioned in 74 days, says the company, which provided the engineering, preparation, removal and disposal (EPRD) services using its Skandi Skansen and Skandi Acergy vessels.

“The works 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,” DOF Subsea says.

“The material was shipped to Aberdeen Harbour’s Clipper Quay for dispersal, with 95% of the material being recycled and 4% being repurposed. Only 1% was sent to landfill as a last resort.”

Fifteen concrete mattresses were repurposed into aggregate for use in roads at the harbour, plastic sheaths from flexible risers and umbilicals were recycled by an approved supplier, and all metal was smelted.

“We are delighted with this outcome as part of one of our biggest subsea decommissioning projects in the North Sea to date,” said Luis Batalla, head of Decommissioning at Repsol Sinopec.

Repsol Sinopec has also announced that the Golden Eagle, Piper and Claymore field owners have executed new agreements reaffirming their commitment to export produced oil to the Orkney Islands’ Flotta Terminal until end of field life in the 2030s.

”This commitment to support the longevity of the terminal underpins a variety of growth opportunities in the wider area, including renewed drilling and several third party tie-backs. All field owners have recently completed successful drilling programmes to increase production volumes and are actively engaged with a number of third parties that are considering the use of the offshore facilities,” the JV said.