(Adds update from Anadarko)
HOUSTON, Sept 1 (Reuters) - Some U.S. oil and gas producers in the eastern parts of the Gulf of Mexico are returning workers to offshore facilities and restarting operations shut as Tropical Storm Hermine as the system moves towards Florida.
Royal Dutch Shell and Enbridge Inc on Wednesday returned personnel to offshore assets as the storm moved away from its operations, and Anadarko on Thursday said it was returning non-essential personnel to its Marco Polo, Constitution and Heidelberg facilities. Non-essential staff will return to Anadarko's Independence facility on Friday, a company representative said.
Shell's Coulomb field, which ties back to the Na Kika platform, will remain shut until downstream assets resume operations.
BP said on Wednesday it had reopened its Atlantis platform, one of three it had idled on the storm threat.
Operators who have pulled workers off platforms in the area include BP Plc , BHP Billiton Ltd and Hess Corp.
Other companies have moved about half a dozen rigs and said they were monitoring the storm, which is expected to make landfall in Florida early Friday morning, according to the National Hurricane Center.
The U.S. government said on Wednesday that so far operators have shut output equal to 312,280 barrels per day of oil equivalent and 360 million cubic feet per day of natural gas production in the U.S. Gulf of Mexico due the storm.
The closures represent 19.5 percent of normal oil output and 10.6 percent of natural gas production in the U.S. Gulf of Mexico, the Bureau of Safety and Environmental Enforcement (BSEE) said. The government's estimate for oil outages was slightly higher on Tuesday.
The shut-ins, while relatively small, represented the most significant weather-related outages for the offshore energy sector since at least 2013 in the United States.
Based on data submitted to BSEE, personnel have been evacuated from 1.3 percent of the 750 manned platforms in the Gulf of Mexico.
The Gulf of Mexico accounts for about 20 percent of U.S. oil production and around 5 percent of natural gas output, according to the U.S. Energy Information Administration.
About 30 percent of U.S. natural gas processing plant capacity and 40 percent of the country's refining capacity is also on the Gulf Coast, mainly around Louisiana and Texas, the EIA has said.
Below is a list of shut-ins confirmed by companies:
-BP has shut two of its four operated platforms in the U.S. Gulf, which have the following design capacities:
Thunder Horse, 250,000 b/d oil, 200 mmcf/d gas
Na Kika, 130,000 b/d oil, 500 mmcf/d gas
-On Wednesday, BP said Atlantis was online after being idled. Its rated capacity is 200,000 b/d oil, 180 mmcf/d gas
-Shell has shut in its Coulomb field, which ties back to the Na Kika platform.
-The Destin Pipeline has evacuated all personnel from its MP260 platform, in the Gulf of Mexico as a precautionary measure against a tropical disturbance. All receipt points, including the Okeanos Gas Gathering System, Marlin and Horn Mountain are shut in. Delivery points, including VKGS are also shut in. Destin is majority-owned by BP with Enbridge Inc a minority partner. (Reporting By Terry Wade and Liz Hampton; Editing by Meredith Mazzilli and Andrew Hay)