WATCH: Taking North Sea oil & gas platform apart piece by piece

Norwegian offshore engineering contractor Aker Solutions has removed a 2,000-ton module from the main structure of a decommissioned oil and gas platform, which used to be deployed at a Repsol-operated oilfield in the southern North Sea.

Following the shutdown of the Repsol-operated Gyda oilfield in the fall of 2021, the topside was transported to Aker Solutions’ Stord yard in western Norway in the summer of 2022 by Allseas’ Pioneering Spirit. With a total weight of 29,000 tons, the Gyda platform has been in the recycling stage since then.

The Norwegian authorities greenlighted the decommissioning plan related to the Gyda field in June 2017, including the permanent plugging of 32 wells on the field along with the removal of the platform, undercarriage, and installations on the seabed.

While production from the field, which started in 1990, ceased in 2020, the P&A work was finalized in October 2021. Archer was in charge of all downhole services on the Gyda P&A campaign with a scope of 14 wells left to plug & abandon. Allseas secured a contract from Repsol for the removal, transfer, load-in to shore, and disposal of the Gyda platform in September 2019.

Following the removal, the platform needed to be dismantled and recycled, thus, Allseas selected Kvaerner, now Aker Solutions, for the job, covering onshore deconstruction and disposal of the Gyda topside and jacket structures. Aker Solutions has dismantled and recycled Gyda’s drilling and flare towers and the associated waste while most of the platform is expected to be recycled soon.

According to the Norwegian player, disassembling an oil and gas platform is no easy task and requires meticulous engineering and planning. However, the company recently tore down a 2,000-ton module from the main structure, using pull force and explosives. For Aker Solutions, this is “an efficient and safe method” to get the structures down to the ground within reach of the large cutting machines.

“The Gyda decommissioning project is a gigantic recycling project, consisting of large quantities of valuable materials that are in high demand on the world market. There is a need for more construction materials. Also, the production of reused steel, copper, aluminum and other materials emits far less CO2 than the production of new materials. Once the project is complete, we expect that around 98 percent of Gyda has been recycled,” outlined the Norwegian player.

Removing 2,000-ton module from decommissioned North Sea platform

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Before the 2,000-ton module was removed, Aker Solutions toppled the decommissioned Gyda field’s 18,000-ton topside in a move that it described as the largest-ever demolition of its kind. Based on data from Stena Recycling, emissions-tracking tools suggest recycled steel is 70% less carbon-intensive than the ore-derived variety, recycled aluminum is 92% less CO2-intensive, and recovered copper is 65% cleaner.

Commenting on the major teardown feat, Thomas Nygård, Head of Aker Solutions Decommissioning, said in October 2023: “The operation was well-planned and executed — a big milestone and team achievement. Projects like these are important for us, they’re important to our clients and they let us return value to the circular economy.”

As the energy transition gains ground and materials costs rise, the decommissioning and recycling of offshore infrastructure such as Gyda is expected to provide valuable building materials for new energy projects. Aker Solutions not only built the jacket for Gyda at Verdal, but it also recycled the 11,000-ton structure.

Marcin Pazdro, Aker Solutions’ Environmental Expert, highlighted: “However you look at it, the recycled steel and other materials recovered from Gyda would represent a sizeable contribution to Aker Solutions or our customers’ own material needs going forward.”