"The dispute between Russia and Ukraine has been driving the market up, although traders are seeing it more as a potential problem rather than an actual one and are reacting just in case."
A London-based broker said Tuesday as the futures prices rose, building on an existing three-day rally as traders reacted to disruptions in gas supply to several European countries Monday as a result of a gas price row between Russia and Ukraine.

See more industry/OPEC viewpoints at http://www.platts.com/Oil/Resources/Quote%20of%20the%20Day/