Sleipnir lifting Tolmount jacket; Source: Rosetti Marino

Sleipnir SSCV installs Tolmount platform in North Sea

Heavy lifting

Heerema’s Sleipnir, the LNG-powered world’s largest semi-submersible crane vessel, has installed the Tolmount platform In the Southern North Sea.

Sleipnir lifting Tolmount jacket; Source: Rosetti Marino

Heerema said on Thursday that the project consisted of installing the 2,350 metric ton jacket and 2,500 metric ton topside constructed by Rosetti Marino.

Sleipnir arrived Tolmount field, located 40 kilometres off the coast of the UK in a water depth of around 51 metres, on October 7.

Sleipnir working at the Tolmount field; Source: Heerema
Sleipnir working at the Tolmount field; Source: Heerema

Installation began on October 12 when the jacket was safely lifted from the Heerema barge H-408. After finalizing jacket and pile installation, Sleipnir lifted and installed the 2,500 metric ton topside on October 13.

The Tolmount jacket and topside arrived at the Tolmount field following a 5,390-kilometre journey from Rosetti’s yard in Ravenna, Italy.

The platform will be a normally unattended installation, located in the vicinity of the 42/28d-13 appraisal well, and will handle wet gas production from four platform wells. The Premier Oil-operated Tolmount field development is on track to deliver first gas in the second quarter of 2021.  

Tolmount platform; Rosetti Marino
Tolmount platform; Rosetti Marino

Rosetti Marino managed the construction and installation of the low-carbon design jacket and topside on behalf of client Premier Oil. The project involved more than 1,100,000 manhours and was completed over a duration of 26 months. It is worth reminding that platform construction for the Tolmount platform began in December 2018.

Michel Hendriks, Heerema transport and installation director, said: “The close collaboration with Rosetti Marino has been a highlight of the Tolmount project. Despite challenges introduced by the ongoing pandemic, we worked together to find creative solutions, which were handled with total professionalism and high regard for safety“.

Lifting of the topside from the barge: Source: Rosetti Marino
Lifting of the topside from the barge: Source: Rosetti Marino

In a social media update on Thursday, Rosetti Marino said that phase two of the project will begin soon and will see the company engaged in hook-up activities until the first quarter of 2021.