For several reasons:
1. In three years, the use of oil cannot be replaced, since although there are several technologies on the market, replacing the oil will take us at least 10 more years.
2. It is a reality that every day there are more political and social conflicts between countries, and this leads to greater consumption of oil, for war, fuel, transport, etc. This will make the barrel price more expensive.
3. The worldwide inflammation factor.
The world still runs on oil. I do not believe 5 years is enough time for technological advances to out do our need to consume oil. The oil industry is worldwide powerhouse so I doubt it will bow away gracefully to competition. Demand determines price so I see it inching up to $100 a barrell.
Although alternatives to oil are gradually penetrating the market, but still oil is one of the main commodities. Many industries depend on it and in my opinion will be depending for the next 10-15 years.
I am praying it becomes unaffordable and everyone is forced to use alternative and renewable energy sources. I also am tired of oil money supporting corrupt and conservative governments around the world.