SHELL EXPRO - SKIFF, BRIGANTINE
North Sea, UK - 1999-2000

Platform

The platforms will be installed in water depths ranging from 100-120 feet. A novel vertical faced 4-leg jacket configuration will be employed. The structure will be lift-installed using a jack-up rig, which will stay on station to drill the wells. The conductors will pass through the jacket legs and act as the foundation system for the facility. Depending on water depth, skirt piles will be used to provide additional foundation capacity.

Challenge

The client had a number of marginal hydrocarbon discoveries (9 in total) that had proved to be uneconomic using traditional North Sea development concepts. The client, in conjunction with MSL, conceived an alternative concept employing technology largely untried in the UK North Sea.

• The platforms are designed for  installation by the same jack-up rig  that will be used to drill the wells.

• Conductors will be run inside the sub-substructure legs and their structural capacity exploited in the design of the foundation.

• The platform will be accessible only by sea and will not have a heli-deck.

MSL have been awarded the detail design of the Skiff, Brigantine BG and Brigantine BR platforms. MSL is responsible for the strength, fatigue and ship impact designs for the substructure, foundation and topsides, including temporary load cases for fabrication, load-out, lift and set-down. MSL is also responsible for the creation of drawings to AFC. MSL was integral to the development of the structural concepts and many novel design solutions and has assisted the client in obtaining regulatory approval throughout the design process.

        Skiff Platform - North Sea, UK

  3-D Isometric Drawing of Skiff/Brigantine

Benefits

The client has identified eight further, previously uneconomic, hydrocarbon discoveries as commercially viable development prospects as a direct result of the success of the field development concept.