There is "peak oil" depending on the price. At $80 per barrel, over 10% of the world's oil production is unprofitable to lift, and at $60 per barrel, 20% of the global supply of oil is too expensive to lift. Currently the average price per barrel averaging West Texas and Brent is running over $100 per barrel. It is fairly easy for OPEC and their associated members to withhold enough supply to keep oil prices from falling - as prices are influenced by the highest marginal rates.

 

http://seekingalpha.com/article/1218901-are-you-expecting-oil-prices-to-fall?source=yahoo