I believe that speculation definitely influenced oil prices, whatever the source. There was a herd stampede out of the securitization market into commodities.
But old fashioned supply and demand really was the #1 factor.
Charts always help:
Production has obviously plateaued since 2005, with an occasional bump. Supply met demand only because of the Great Recession. It will be interesting to see what the future holds. Most oil producers keep the taps running so to speak. Whereas the middle east producers like Saudi Arabia, Kuwait, UAE, have the luxury of decreasing production when prices fall.
Saudi Arabia's oil fields are unaudited, and there are some experts that believe Saudi Arabia may have peaked. It's rig counts have practically tripled in the past few years, yet production remains relatively flat. They have also recently hired Haliburton to drill in the Ghawar field (the world's largest). Draw your own conclusions.
I believe that depending on economic recovery here, or oil usage in developing countries especially India and China, oil could easily break the $150 a barrel... and then, we would have another economic shock. I expect a seesaw of economic activity from here on out impacted by a very volatile oil market.
There is no real bridge fuel alternative that would make a transition seemless.