Just remember...this is the definition of what unrestrained capitalism gives you. Unlike almost every other consumer good, the demand curve for oil is very inflexible. Therefore, a huge increase in price causes only a very small decrease in consumption.
The oil market is unlike almost any other market in that effect. If you need a new vacuum, and 1 brand has a price too high, you simply choose a different brand. But if you have a certain amount of miles to drive to work, you have to drive those miles whether gas costs $1.50 or $4.00 a gallon.
Therefore, it is to the advantage of oil companies to drive the price up...because even though they're driving the price up, they're not driving demand down. Therefore, if they want to maximize profits...they can keep pushing the price even higher.
Here's a nice little post on the reasons no refineries have been constructed in this country in decades...and why oil companies are even trying to close some profitable ones down.