The arctic region has iconic status in many people’s eyes, with sea ice and polar bears at the top of people’s watch list for signs of climate change. (Images courtesy of DNV)

The US Geological Survey has estimated that the Arctic basins could contain as much as 25% of the world’s unexplored hydrocarbon reserves. These potentially vast reserves are balanced with the specific and quite extreme challenges of this unique region.

The arctic environment is perhaps one of the most pristine left on the planet and realistically also one of the most at risk. Studies have shown the persistence of pollutants in ice to be far greater than in more temperate climes. The arctic region has iconic status in many people’s eyes, with sea ice and polar bears at the top of people’s watch list for signs of climate change; so oil and gas industry interference and damage to this area could be construed in a particularly high-profile and detrimental light.

As oil and gas activities move to the High North, interaction with seasonal and permanent ice cover becomes unavoidable. From a structural viewpoint, the loads imposed by the pack ice or drift ice can be the dominant load condition, especially in regions where multiyear ice, thicker and often stronger than first year ice, is present. The ice load can govern the structural form, particularly the requirement for continuous ice-breaker assistance for floating structures.

From an operational viewpoint, the installation and construction season is very short and can in some areas be limited to as little as two to three months between ice melt and formation.

Managing harsh risks

Rational schedule risk management is essential to accurate field development, which in turn requires accurate environmental ice condition forecasting. Re-supply and logistics are also complicated by permanent ice cover, and ice breaker assistance can be required. If the field development plan uses tankers rather than a dedicated pipeline, the ice handling capacity of the tankers needs to be assessed and the slower speed of transit out of the ice considered.

The arctic presents a particularly difficult working environment for personnel. Extreme cold and the Polar night are challenging to work in. This environment complicates common approaches to emergency escape and rescue. For example, launching conventional lifeboats on a permanent ice cover is not productive, and if not prepared, evacuation of personnel into the harsh arctic weather could be just as dangerous as the situation the personnel were escaping from.

For the assessment of ice actions on ships, structures, and pipelines, the characterizing of the dominant ice regime is a critical facet in the design process. Sea ice is a naturally occurring geo-material, which is principally solid, but is perhaps more adequately described as a porous or granular material. Sea ice exists close to its phase change temperature and as such is highly susceptible to local temperature variations. Ice strength is highly linked to the temperature and mechanical history during the formation and consolidation of the ice. Mechanically deformed ice, in the formation of ridges, can act to greatly increase the effective thickness of the ice cover — with substantial impact upon transit and operational loads.

Identification of rational characteristic ice features for floating and subsea design options requires greater resolution, as practical experience of these facilities in High North regions is limited. Conventional statistical techniques, used to generate deterministic, semi-probabilistic or fully probabilistic assessment of the ice regime, result in a high degree of uncertainty. Handling this uncertainty is one of the critical issues.

Joint efforts for safer operations

Joint industry projects (JIPs) are one of the most effective means through which safe and sustainable developments in the arctic regions can be achieved. The JIP vehicle allows complementary experience and knowledge sharing among researchers, operators, and service contractors. There is a great deal of activity in this sector, looking at a range of issues from specific equipment winterization to material response at low temperatures and human operator competencies and training requirements.

A key focus in JIP activity is the development of new codes of practice for arctic operations and technology. The recognized ISO 19906 “Petroleum and natural gas industries - Arctic offshore structures” standard represents a concerted effort from operators, designers, researchers, and service contractors to present the current state of the art for accepted design principles and approaches to the design of arctic offshore structures. Supporting this Standard is a JIP toward a new Recommended Practice (RP), DNV-RP-C209. The RP will provide practical and consistent design recommendations for fixed and floating structures in ice. It will provide guidance where existing codes are incomplete, silent, or merely provide functional requirements.

The existing design code structure does not provide implicit or explicit guidance for the design and operation of arctic pipelines. Project specific design approaches and knowledge retention by key contractors is currently the norm. There is a wide variation in the accepted design principles and probabilistic approaches currently employed to characterize the threats to arctic pipelines.

The focus of the JIP addressing arctic offshore pipelines is on describing methodologies for qualifying assessment tools and in generating rational characteristic values to describe the governing ice regime during the lifetime of the pipeline system. Particular attention is being paid to ice gouging and optimized pipeline burial depth, where assessment methodologies and tools are very much on the cutting edge of technological development.

A third focus is marine icing. Marine icing presents a large potential threat to the stability of vessels operating in cold climate regions due to ice accretion on the superstructure. The new MAR-ICE JIP aims to provide predictive tools for and mitigation measures against atmospheric and sea spray icing for oil and gas related marine activities in the High North.

Marine operations in ice-covered waters present additional significant challenges, not only to the structural response of the vessel, but to the crew’s capacity to react to a dynamic loading situation. Maritime simulators are becoming an increasingly prominent method for planning drilling and construction activities to optimize ice breaker assistance. Several projects are currently under way and in development to create standards of competence and certify maritime learning programs.

A recent standard publication on “Competence of Officers for Navigation in Ice” is one example of the results of this sort of research.

Improving technology can assist in managing risk in arctic operations. A prime example is the development of a new system to monitor actual ice loads acting on the ship hull and to display “utilization” factors to the bridge. Improving procedures for operating in arctic regions is equally important. Another JIP is examining new procedures for ship-to-ship transfer of LNG in open waters — a topic that is particularly relevant for the potential transport chain of LNG production in northern Russia.

Sharing the load

Challenges to developing safe, sustainable oil and gas activities in the High North are legion; however the list of innovative projects to meet the challenges of the new arctic frontier is significant. JIPs offer a way to optimize development of the tools needed to deliver safe and cost-optimized projects in the High North. Such JIPs
cannot hope to address all of the challenges in one succinct package, but when examined together, present defined solutions to an increasing number of the new challenges this exciting frontier presents.