The largest oil field in the United States has been shut down.

BP Exploration Alaska announced that over the next several days, it will cease production at Alaska's Prudhoe Bay. The field produces roughly 400,000 barrels a day.

The decision came after the company discovered what it called “unexpectedly severe corrosion and a small spill from a Prudhoe Bay oil transit line.” Officials said the repair work will include up to 73 percent of the pipeline, and could take weeks or even months before it is fully repaired.

The effect on oil markets was quick. Light, sweet crude had reached a record high of $77.30 on the New York Mercantile Exchange as of press time.

A BP press release indicated it has contained the spill and started clean-up efforts.

Meanwhile, The Associated Press reported that the Energy Department has a plan in place to pull oil from the Strategic Petroleum Reserve if it's needed to keep fuel flowing.