What's driving the Oil Rally ? is it an Oil Bubble ?

The crude oil prices doubled in less than 6 months going from $35 to the $70 of last week , are these real fundamentals driving the prices do people really believe that the economy has recovered ? or is it just another speculatory bubble ready to burst in short term ..there is a wave of commodities money coming into the market as a hedge against inflation , this is not a rally you could rely on , the soaring demand is missing from this rally , this has nothing to do with last years rally which was driving by the demand and shoots crude oil prices to a record of $147 a barrel , there is also the dollar factor which is in a stronger place this year than it was last year