A floating platform for arctic regions is required to break ice and withstand high ice loads, be disconnected and towed away in the event of approaching icebergs, leaving the mooring lines and risers in-place, support large topsides and provide large quantities of utility storage. Additionally the platform should provide low motion response to storm and ice loads to maximize the operational uptime and enable the use of current state-of-the-art riser systems.
This paper presents the details of a Spar platform that has been configured to satisfy all requirements for Arctic operation. The paper describes a number of key features that are specifically designed to reduce ice loads on the hull and to allow ice floes to break around the hull without damaging the hull, topsides, mooring or risers, while maintaining the characteristic low motion response to storm environments. The paper also describes the system for disconnecting and reconnecting the moorings and risers in response to approaching large icebergs.
A floating offshore production platform suited for Arctic service where sheet ice and icebergs are prevalent has to be designed to satisfy the following key requirements:
Withstand high ice loads during winter without damaging the hull, topsides or the risers
Provide satisfactory performance due to ice loads and storms during non-winter months to protect the risers and provide high uptime for platform operations
Maximize uptime through good operational performance
Be able to disconnect from its mooring and risers and be towed away in case of an unavoidable iceberg or an extremely large ice floe that may induce damage to the hull, topsides, mooring or risers
Have large capacity to store utilities in the hull to plan for limited supply boat trips
Spar has been considered as a floating platform for Arctic application because of its superior performance and its ability to minimize the ice loads, protect the risers and display consistent response in all directions to the storm environment or ice loads. The following sections will describe the Spar system, mooring and riser configurations designed for quick disconnection and reconnection.