By Kristen Hays and Erwin Seba
HOUSTON (Reuters) - Gulf of Mexico oil and gas producers on Wednesday were restarting operations after Tropical Storm Lee was long gone, even as they monitored another system in the far southwest part of the basin.
That low-pressure system, which models showed could cross the Bay of Campeche into Mexico or turn northeast and head for the U.S. Gulf Coast, had a 60 percent chance of becoming a tropical cyclone in the next two days, the National Hurricane Center said.
U.S. crude oil prices rose more than $3 a barrel on Wednesday, bolstered in part by the slow recovery post-Lee and the threat of further weather-related disruptions to energy infrastructure.
More than 60 percent of Gulf oil output remained shut on Tuesday -- nearly 850,000 barrels per day (bpd) -- several days after Lee came ashore and weakened on Sunday. U.S. regulators were slated to release updated shut-in figures later Wednesday.
Gulf Coast refined products traders said on Wednesday they saw no weather-related impact on differentials. "Nothing in the Gulf," one Gulf trader said.
Kelly op de Weegh, a spokeswoman for major Gulf oil and gas producer Royal Dutch Shell said on Wednesday that the company was continuing to redeploy workers to Gulf platforms and was ramping up production.
"We are also monitoring the system in the southern Gulf of Mexico and will take pre-storm precautionary measures if necessary," she said.
Other companies, including the Gulf's biggest oil producer, BP Plc, also said they were monitoring the yet-unnamed system.
While Lee came ashore and weakened on Sunday, high winds and rough seas in its wake lingered along the Louisiana coast, hampering companies' restart efforts in areas south of Louisiana and Mississippi. Such conditions ground helicopters needed to ferry workers and idle support ships.
Weather conditions improved early Tuesday, allowing those efforts to move forward.
Exxon Mobil Corp spokesman David Eglinton said on Wednesday that the company was ramping up production shut for Lee and monitoring the other system.
The Gulf's two areas with the heaviest concentrations of oil and gas infrastructure -- Mississippi Canyon and Green Canyon -- are south of Louisiana.
(Editing by Alden Bentley)