The Federal Reserve announced its third phase of quantitative easing last week, and oil prices immediately saw a short-term boost.

Crude oil prices even crested the benchmark $100-per-barrel mark after the Fed announced its latest round of economic stimulus. The move came the same week that the European Central Bank announced it would buy billions worth of Eurozone bonds to help insulate the region’s economy in the face of spiraling debt problems in Italy and Spain.

Julian Jessop, chief global economist at Toronto-based Capital Economics, warned oil investors not too ...