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In this paper we will review the loss of the Kolskaya jack-up platform and 53 crew members in the Sea of Okhotsk during New Year 2011- 2012 and point to causes of the loss. Thereafter we will review the near disaster when the Kulluk rig was being towed from Alaska to the US in January 2013. Although both towing incidents could have led to disasters, the operator, Shell, was capable of rescuing all personnel and getting Kulluk off its grounding and back to a safe haven. The Kolskaya incident did, however, have a sad and tragic outcome. Both incidents happened during towing in harsh weather and we will in particular discuss the characteristics of the rigs and the concerns regarding safe towing. These include: - An evaluation of the rigs’ motion characteristics in large waves (Kulluk has particularly difficult motion characteristics in waves); - Safe tow using at least two tugs to ensure redundancy during the tow; - The need to move non-essential personnel off a rig during the tow; - Management awareness of harsh Arctic conditions. The outcome of the incidents will thereafter be discussed with an emphasis on the ability to save a rig of the Kulluk type and the loss of confidence in Russian project management in the case of Kolskaya. We will also discuss how confidence in Arctic activities could be restored. Based on the analysis, we will prepare recommendations for thorough risk analysis, in particular prior to critical tow operations. We will also highlight the responsibility of the marine staff involved in such operations and the need to strengthen their role. Of importance is the need to educate all those involved about the conditions of the physical environment. The companies’ safety programs must be updated in the case of Arctic operations with an emphasis on the need for patience and an awareness of the costs for Waiting on Weather.

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 paper focuses on a comparison of sub sea and surface petroleum developments and discusses the application of sub sea developments in Arctic waters. The paper highlights the benefits of sub sea developments and compares these to the benefits of surface developments. Among important parameters to consider are the water depths at the sites and the ice conditions, as well as the regularity of the operations. Reference are given to developments on the Canadian Shelf offshore Newfoundland and to recent developments in the Barents Sea where the Snøhvit development represents the first full field sub sea development in the Arctic. The potential for extension of the Snøhvit technology to deepwater Arctic gas condensate fields is discussed. It is emphasized that the ice conditions have to be taken into account when selecting field development concepts for the Arctic offshore.

This paper focuses on marine assets for subsea intervention operations in regions with harsh environmental conditions, from field development to inspection, maintenance and repair (IMR) during the production stage of the field. Topics treated are typical environmental conditions, remoteness and distances of transportation, desired vessel functional requirements and characteristics, as well as examples of operations and discussions about vessels.