A tropical depression is expected to form late on Wednesday or Thursday, according to the National Hurricane Center, and move westward across the northern Gulf of Mexico, home to dozens of oil and gas producing facilities.
Chevron Corp, Royal Dutch Shell Plc, BP Plc and BHP are removing staff from 15 offshore energy platforms, according to company statements.
Chevron is evacuating and initiating production curbs at five platforms, Big Foot, Blind Faith, Genesis, Tahiti and Petronius platforms, spokeswoman Veronica Flores-Paniagua said.
The U.S. oil major is also removing non-essential staff from a sixth facility, the Jack/St. Malo, as a precaution.
Shell said it evacuated non-essential staff on the Appomattox, Mars, Olympus and Ursa platforms and reduced oil production by about 2,535 barrels per day (bpd) on its Mars and Olympus platforms. It expects minimal impacts to operations.
BP began to evacuate four platforms, the Thunder Horse, Atlantis, Mad Dog and Na Kika, which produce more than 300,000 barrels of oil equivalent per day, said spokesman Jason Ryan.
BHP was ramping down production and expected to complete staff departures from its Neptune and Shenzi production platforms by Wednesday afternoon, said spokeswoman Judy Dane.
The Gulf of Mexico is home to 17 percent of U.S. crude oil output and 5 percent of natural gas output daily, according to the U.S. Energy Information Administration.
On Tuesday, forecasters at Colorado State University predicted six hurricanes, including two with up to 111 miles per hour winds (179 kph), will form during this year's Atlantic hurricane season, which runs from June 1 to Nov. 30.
(Reporting by Collin Eaton in Houston, Editing by Rosalba O'Brien, Cynthia Osterman and Sandra Maler)