[Editor’s note: This story was updated at 2:41 p.m. CT Oct. 7.]

Oil and gas workers withdrew en masse from offshore production facilities, and onshore refineries began storm preparations on Oct. 7 as Hurricane Delta was forecast to intensify into a powerful, Category 3 storm as it crosses the Gulf of Mexico (GoM).

UPDATE:

Hurricane Delta Shuts Over 90% of US Gulf of Mexico Oil Production

Delta's winds declined to 105 mph (169 kph) as it tore across Mexico's Yucatan peninsula. But it is expected to enter the Gulf of Mexico and strengthen with winds of up to 120 mph, the National Hurricane Center (NHC) said.

Hurricane Delta shut 80.4% of offshore crude oil production in the U.S.-regulated northern GoM by midday on Oct. 7, the U.S. Bureau of Safety and Environmental Enforcement (BSEE) said.

The hurricane, forecast to strike the central U.S. Gulf Coast late this week, also idled 49.2% of natural gas output from the Gulf, BSEE said.

Oil producers had evacuated 183 offshore facilities in the U.S. GoM by Oct. 7 and halted nearly 1.5 million bbl/d of oil and 1.33 Bcf/d of natural gas production. The region accounts for about 17% of U.S. oil output.

Energy prices were mixed. Natural gas futures were up more than 3% on storm shut-ins, U.S. crude oil futures fell 2% and gasoline futures declined nearly 3%.

Onshore oil and gas processing plants began securing operations, and the U.S. Coast Guard warned vessels of gale force winds at Louisiana ports in the coming days.

Royal Dutch Shell Plc was preparing three refineries in Convent, Geismar and Norco, La., for Delta's arrival. Louisiana Offshore Oil Port, the sole deep water port on the GoM, halted seaborne exports and imports.

Delta likely will generate a life-threatening storm surge and strong winds "over a large portion of the northwestern and northern Gulf coast," the NHC warned. Louisiana officials advised residents of low-lying and coastal areas to evacuate.

The hurricane could strike Louisiana on the weekend as the 10th named storm to make a U.S. landfall this year, eclipsing a record that has held since 1916.

Oil companies have had to evacuate offshore workers repeatedly this year with departures and returns complicated by pandemic quarantines and virus testing.

Delta was at least the sixth time some energy companies have had to remove staff and curtail production since June.

W&T Offshore Inc. estimated the storms cost it 9,000 bbl/d of oil and gas in the latest quarter, more than a fifth of its targeted output.

Delta will delay the restart of its Lake Charles refinery, a Louisiana plant shut in August by Hurricane Laura, said refiner Phillips 66. A second Phillips plant, on the Louisiana coast, has remained closed for maintenance since a mid-September storm.

Shell, the largest GoM offshore oil producer by volume, evacuated staff from nine facilities and Chevron Corp. evacuated and shut production on all its GoM platforms. BP Plc, BHP Group Plc, Occidental Petroleum Corp., and Murphy Oil Corp. pulled workers out and halted some production.