((Automated translation by Reuters, please see disclaimer https://bit.ly/rtrsauto))
(Added Chevron and Shell bringing back offshore staff and resuming production in paragraph 4)
More than a quarter of oil production and 16% of natural gas production in the Gulf of Mexico remained offline following Storm Rafael, the US offshore energy regulator said on Sunday.
Production of 482,790 barrels of oil and 310 million cubic feet of natural gas was halted Sunday, the Bureau of Safety and Environmental Enforcement (BSEE) said.
Oil and gas workers remained evacuated from 37 of the region's 371 manned production platforms, or about 10 percent, while two drilling vessels remained away from their previous locations, BSEE said.
Chevron CVX.N and Shell SHEL.L have started bringing workers back to their offshore facilities, the two Gulf of Mexico producers said on Sunday. Shell also returned its drillships to their previous locations after storm-related interruptions, a spokesperson said.
Production losses from the Rafael shutdowns total 2.07 million barrels of oil and 1.12 billion cubic feet of natural gas to date, according to BSEE data.
Federal oil production from the Gulf of Mexico represents approximately 15% of total U.S. crude oil production and 2% of dry natural gas production.
The storm was downgraded to a tropical storm after entering the Gulf on Wednesday as a major hurricane. It is expected to meander through the central Gulf of Mexico, then turn south and southwest Monday and Tuesday, according to the U.S. National Hurricane Center.
