Heerema’s semi-submersible crane vessel Sleipnir has installed Dana Petroleum’s new P11-Unity platform. At 395 metric tonnes, this is one of the world’s smallest platforms. The contract was awarded by HSM Offshore, which fabricated the platform at its yard in Schiedam, the Netherlands.

On October 22, Sleipnir lifted the P11-Unity platform from the vessel’s deck to the seabed, with this operation taking around an hour. P11-Unity will support the development of the Witte de With and Van Ghent East gas accumulations, using a new “back-to-basics” design platform to produce two fields.

Heerema’s scope included the lifted load-out of the P11-Unity platform from HSM Offshore’s quayside at Schiedam. The lift was executed by Bonn & Mees on October 15 and the platform was loaded-out onto the 122-metre long Heerema owned barge H-406. After that the P11-Unity platform was transferred to Sleipnir’s mooring location at the Port of Rotterdam by Muller, arriving on October 17.

After the completion of the Tolmount installation, Sleipnir arrived in the Port of Rotterdam to lift the P11-Unity platform onto the vessel’s deck on October 19 and secured the tripod for transportation to the offshore installation location. The vessel mobilised on October 22, and after an 8-hour sail, Sleipnir arrived on location, in Block P11b, around 67 kilometres off the coast of Scheveningen, the Netherlands.

HSM Offshore managed the construction and installation of the platform on behalf of Dana Petroleum, including contracting Heerema’s Sleipnir for the offshore scope.

Remotely operated

The P11-Unity platform is a minimum facilities wellhead platform that was pre-commissioned onshore to minimise the offshore construction scope. The platform is designed for marine access only, using similar principles to the offshore wind industry. It will be remotely operated from the host P11-B-De Ruyter platform, also operated by Dana Petroleum. The P11b Unity Development Project expects first gas in the second half of 2021.