U.S. energy companies were returning workers and restarting operations at storm-swept production facilities along the U.S. Gulf Coast on Sunday, two days after Hurricane Delta barreled through the area. Chevron Corp, Royal Dutch Shell Plc and BHP Group all said workers were headed back to production platforms in the U.S.-regulated northern Gulf of Mexico. BHP expects to complete the return of workers to its Shenzi and Neptune production platforms on Sunday, spokeswoman Judy Dane said, adding that resuming flows will depend on how quickly pipelines return to service. It can take several days after a storm passes for energy producers to evaluate facilities for damage, return workers and restore offshore production. The companies that operate oil and gas pipelines and process the offshore output also shut ahead of the storm. On Sunday, the U.S. Bureau of Safety and Environmental Enforcement (BSEE) said 91% of offshore crude oil production remains shut in the U.S.-regulated northern Gulf of Mexico following Hurricane Delta, which made landfall on Friday night. In addition, 62.2% of natural gas output remains shut in the Gulf following the storm that made landfall near Creole, Louisiana, and weakened into a low-pressure system over Mississippi on Saturday. Through Sunday, a cumulative total of 8.8 million barrels per day (bpd) of crude oil production and 8.3 billion cubic feet per day of natural gas output from the Gulf has been shut because of Hurricane Delta. The area produces about 17% of total daily U.S. oil production and 5% of daily natural gas production. Still remaining shut are the Calcasieu Waterway in Calcasieu and Cameron Parishes in Louisiana and the ports of Lake Charles and Cameron, Louisiana, near where Delta made landfall. The ports of Beaumont and Port Arthur, Texas, including the Sabine Pass, which serve major oil and liquefied natural gas processing plants, were reopened with restrictions on Sunday, the U.S. Coast Guard said. Total SA continued restarting its 225,500 barrel-per-day Port Arthur, Texas, refinery on Sunday. The refinery, which is about 65 miles (100 km) west of Creole, Louisiana, lost power on Friday. Fast-moving Delta swept over Louisiana on Saturday and became a low-pressure system over the U.S. state of Mississippi later that day. It was south of Knoxville, Tennessee, Sunday morning and moving northeast at 16 mph (25.7 km per hour). Remnants of Delta were forecast to drop 3 inches to 6 inches (7.6 to 15.2 cm) of rain on parts of Tennessee, the Appalachian region of northeast Georgia, western Carolinas and western Virginia, the National Hurricane Center said on Sunday.