Exxon Mobil said on Monday it was evacuating personnel from a Gulf of Mexico platform as U.S. forecasters predicted Hurricane Michael would become a major hurricane this week.

The National Hurricane Center upgraded the storm on Monday morning to a hurricane with wind speeds of up to 75 miles (120 km) per hour and forecast it to become a category three hurricane. Michael is tracking through the energy-producing area of the Gulf of Mexico and expected to make landfall near the Florida Panhandle.

The world's largest publicly traded oil producer does not currently expect the staff reduction at its Lena production platform to affect output, spokeswoman Julie King said.

Offshore production in the Gulf accounts for 17 percent of total U.S. crude oil output, according to the U.S. Energy Information Administration. Natural gas production from Gulf offshore operations provides 5 percent of the U.S. total.

Over 45 percent of U.S. refining capacity is located along the Gulf Coast, along with 51 percent of the nation's natural gas processing plant capacity, the EIA said.

Production platforms are permanently attached to the sea floor and cannot be moved. Rigs, used for exploration, can be towed to drill at different sites.