With considerable amount of oil and gas resources, the Arctic zones are becoming more and more attractive for oil and gas exploration and production. However, to be able to produce oil and gas in this region, several new challenges have to be faced. One of these is the heavy ice condition. Thus, to face this challenge, new technologies are required. In drifting ice to heavy ice conditions, a floating stationary unit must withstand the important design ice loadings. Due to these loadings, a safe design of the vessel to seabed connection, however, cannot rely on thrusters’ utilization alone. A mooring system needs to be particularly reliable and strong. Eventually, disconnection may be needed in the event of loss of position [Gudmestad et al., 09].

With regard to these observations, it seems relevant to compute and analyze the loading in the mooring device. The vessel studied in this paper is a moderately sized mono-hull icebreaker suitable as an offloading terminal for deep or shallow water production systems or onshore facilities, as control centre for subsea facilities, as process facility with a small process plant or as an intervention vessel for subsea satellites.

The Arctic Ocean has a water depth varying from tens of meters (Pechora Sea and Kara Sea as well as parts of the Beaufort Sea) to a couple of thousands meters (Canada Basin). This implies finding different mooring solutions to suit these different water depths.

Due to weight limitations, it is challenging to design a mooring system for arctic deep water made of chain or wire. The partial use of polyester ropes may be an attractive alternative. Due to its particular features, the polyester rope’s behavior is not fully understood and it is needed to be further studied for use with a moored installation in this region with very large mooring forces. This paper aims at presenting the results of ice load calculations on mooring systems composed of different kinds of mooring elements (polyester ropes, wire ropes, chains and buoyant elements) and proposing different geometries according to the water depth.

This content is only available via PDF.
You can access this article if you purchase or spend a download.