The metocean conditions in the Barents Sea entail lower temperatures, and more snow and icing on offshore structures than what can be expected further south on the Norwegian Continental Shelf. The conditions are not considered extreme compared with other Arctic waters, but low temperatures, accumulation of snow and icing on structures and equipment may affect operations and equipment functionality. To manage these issues and ensure a safe working environment, winterization of installations is necessary. This article describes some results from a winterization study executed for the Petroleum Safety Authority Norway. The study objective was to provide an overview of known solutions and measures for winterization related to low temperatures, snow and icing for drilling rigs and production platforms operating in the Norwegian part of the Barents Sea. The study also describes solutions and measures that may be applicable at different locations in the Barents Sea, and available standards and guidelines related to winterization. Issues related to sea ice, bergy bits and icebergs have not been addressed.
As a part of the study, winterization standards and manuals for drilling rigs and production platforms were reviewed, along with available experience from previous and ongoing projects. The information was systematized, and a high level summary produced. The results showed that the main issues related to low temperatures, snow and icing for rigs and platforms operating in the Barents Sea can be simplified and summarized as follow: 1) Snow and icing on exposed surfaces. 2) Freezing of fluids in piping/equipment/tanks. 3) Personnel exposure to low temperatures and weather. These issues were further categorized to include typical areas and equipment types. Several solutions and measures were identified for each of them. The study showed that most of the identified solutions and measures are applicable for most locations in the area open for petroleum activities. However, more permanent and robust solutions should be selected for the coldest areas, as icing rates increases, and wind chill temperature decreases with lower temperatures.
The review of winterization manuals also showed the importance of implementing organizational and operational measures related to winterization. Education and training in proper use of winter technology, and defensive behaviour with respect to falling ice and slippery surfaces were identified as some of the most important measures to avoid incidents. Checklists for inspections, before and during the winter season, are important measures to secure areas and equipment when temperatures fall towards freezing point.
The study results show a large variety in available solutions and measures for each issue. These shall, combined with organizational and operational measures, ensure safe operations in the Barents Sea. The study shows that the challenge is not whether solutions and measures exist, but in finding the right combination of them for different conditions at specific locations.
