Nordea's global commodities team, consisting of oil analyst Thina Saltvedt and commodities strategist Bjørnar Tonhaugen, was remarkably accurate in its 2013 oil forecasts.

Among 43 analysts from banks and research institutes worldwide who report their forecasts to Bloomberg, including major banks such as Goldman Sachs, Barclays, Deutsche Bank, China International and Bank of America Merrill Lynch, the Nordea oil team came in at the top.

"In 2013 oil prices will on average remain quite close to the current level, slightly weaker at the beginning of the year and then increasing somewhat on the back of improved economic growth. The average price will be USD 108/barrel, rising to about USD 110/barrel in Q4," the team said in an email to Bloomberg in December 2012.

The average price in 2013 was $108/barrel and $109/barrel in Q4.

"It's hard to forecast prices 12 months ahead of a product whose price depends on so many different factors. Many of the world's oil reserves are found in regions without stable political regimes. Moreover, weather conditions are crucial for both production and consumption," Saltvedt said. "Going forward, international climate policy will play a larger role. Rival energy sources such as coal, gas and nuclear power also affect oil prices. Against this background it's even more gratifying to be as accurate as we were last year."