The United States experienced a steep decline in refining capacity between 1981 and the mid-1990s. Between 1981 and 1989, the number of U.S. refineries fell from 324 to 204, representing a loss of 3 million bbl/d in operable capacity (from 18.6 million bbl/d to 15.7 million bbl/d), while refining capacity utilization increased from 69 percent to 87 percent. Much of the decline in U.S. refining capacity resulted from the 1981 deregulation (elimination of price controls and allocations), which effectively removed the major prop from underneath many marginally profitable, often smaller, refineries.
Refinery closures have continued since 1989, bringing the total number of operable U.S. refineries to 148 as of January 1, 2005. In general, refineries that have closed were relatively small and had less favorable economics than other refineries in their market area. Also, in recent years, some smaller, less-economic refineries that needed additional investments for environmental reasons in order to stay in business found closing preferable because they predicted that they could not stay competitive in the long term.
While some refineries have closed, and no new refineries have been built in nearly 30 years, many existing refineries have expanded their capacities. As a result of capacity creep, whereby existing refineries create additional refining capacity from the same physical structure, capacity per operating refinery increased by 28 percent over the 1990 to 1998 period. Overall, since the mid-1990s, U.S. refinery capacity has increased from 15.0 million bbl/d in 1994 to 17.1 million bbl/d in September 2004. As of November 4, 2005, utilization of operating capacity at U.S. refineries was averaging around 84 percent, down from 91 percent on September 16, 2005 following Hurricanes Katrina and Rita.