Crude oil price did indeed rise dramatically starting in 2004. By mid-year 2005, the nominal price of crude oil had hit $60 per barrel ( a real price of about $37 per barrel ). Although drilling did pick up a bit late in 2004, producers responded rather cautiously to this new price, in part because they were not sure it would last. Another factor slowing the price response was the tendency to bring many formerly shutdown wells back on line. With the new higher price, operators found that they could now cover the high variable costs associated with these wells.