Sleipnir installs Dana Petroleum's P11-Unity Platform

The world’s largest semi-submersible crane vessel Sleipnir has safely installed Dana Petroleum’s new P11-Unity platform, which at 395 metric tons is one of the world's smallest platforms. Heerema was contracted for the transportation and installation of P11-Unity by HSM Offshore, who fabricated the platform at their yard in Schiedam, The Netherlands.

On October 22, Sleipnir safely and sustainably 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 on to the 122 m 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 on to the vessel’s deck on October 19 and secured the tripod for transportation to the offshore installation location. The vessel mobilized on October 22, and after an eight hour sail Sleipnir arrived on location, in Block P11b, around 67 km 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. P11 Unity was constructed at the HSM Offshore yard in Schiedam, with the HSM workforce spending around 28000 working hours on the platform.

The P11-Unity platform is a minimum facilities wellhead platform that was pre-commissioned onshore to minimize 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.

Throughout the 55,000 hours worked on the project to date there has been zero recordable HSE cases, the result of strong cooperation and a high regard for safety from all parties. While Sleipnir utilized its wide range of sustainability measures throughout the project, including running on LNG for the entire installation duration.