Shell Oil UK
Shell Skiff Field Development: Platform Installation by Jackup Rig
ICON Engineering was commissioned by Shell to provide assistance with the installation of the Skiff wellhead platform in the Southern North Sea. The platform was installed by a jackup drilling rig.
Installing Shell's Skiff wellhead platform, North Sea
This was the first platform to be installed by this means in the UK sector of the North Sea. The installed cost was a fraction of that required using conventional methods.
The project won the British Government Construction Industry Civil Engineering Award for 2000 in recognition of the novel design and installation method which challenged traditional practices.
ICON's involvement at the client level allowed Shell to take advantage of our site experience with this style of installation. ICON's scope included review of: installation methodology, critical success factors, schedule, key deliverable's for contractors, installation criteria and risk (safety and schedule) reduction. ICON also assisted with management of key interfaces and contractors and attended offshore during the installation.
The platform jacket and topsides were transported to site on a small flat top barge. Transporting the Jacket vertically eliminated the need for upending. The barge was moored to the rig legs. Four 30 inch skirt piles were preloaded into the pile sleeves to reduce rig time during pile make-up.
Lifting off the Skiff jacket
The platform mudmat is minimal as the structure is stabilised by the rig during piling. After lift-off and placement the piles were installed using a drill-drive procedure which limits formation damage and guarantees penetration.
Topsides installation occurred after piling. Drilling commenced immediately after the topsides installation.
Lowering the topsides onto the Skiff jacket
|Jacket Lift Weight||450t (incl pre-loaded piles)|