(Updates with forecast of storm becoming hurricane)
By Erwin Seba and Jessica Resnick-Ault
HOUSTON/NEW YORK, Sept 3 (Reuters) - Anadarko Petroleum Corp said on Monday that it had evacuated workers and shut production at two oil platforms in the northern Gulf of Mexico ahead of the approach of Gordon, which is expected to come ashore as a hurricane.
The company pulled workers from the Horn Mountain oil platform and Marlin oil and natural gas platform, located 100 miles (161 km) and 75 miles (121 km), respectively, southeast of Louisiana in the Gulf.
Chevron Corp oil and natural gas production levels at its offshore operations remained normal on Monday, company spokeswoman Veronica Flores-Paniagua said.
The U.S. Coast Guard warned that the ports of New Orleans and Gulfport and Pascagoula, Mississippi, may have to close within 48 hours due to the risk of gale force winds from Gordon, which is expected to make landfall near the border between Louisiana and Mississippi on Tuesday night
All three ports remained open on Monday.
Refineries in the U.S. Gulf Coast states of Louisiana and Mississippi made preparations on Monday for the storm to come ashore late Tuesday.
Chevron also said on Monday staff at its 352,000 barrel per day (bpd) refinery at Pascagoula, Mississippi, were monitoring the storm carefully and preparing the plant for wind and rain. The Pascagoula refinery is closest to the landfall location currently forecast for Gordon.
Royal Dutch Shell Plc plans to increase staffing at its 218,200 bpd Norco, Louisiana, refinery west of New Orleans, as it prepares the refinery for high winds, said sources familiar with plant operations.
PBF Energy was securing scaffolding in preparation for high winds at its 190,000-bpd Chalmette, Louisiana, refinery, sources familiar with operations at the refinery said.
Valero Energy Corp was readying its 125,000-bpd Meraux, Louisiana, refinery on the east side of New Orleans, said sources familiar with plant operations.
The Gulf of Mexico is home to 17 percent of U.S. crude oil and 5 percent of natural gas output daily, according to the U.S. Energy Information Administration.
More than 45 percent of the nation’s refining capacity is located along the U.S. Gulf Coast, which also is home to 51 percent of total U.S. natural gas processing capability. (Reporting by Erwin Seba in Houston and Jessica Resnick-Ault in New York Editing by Cynthia Osterman and Sandra Maler)