Oil and gas workers began retaking the offshore sites Friday and federal officials said that 377 of the 596 productions platforms have some staffing on them, up from just 97.
Yet officials estimate that 94 percent of oil production, and about 65 percent of natural gas production in the Gulf of Mexico, remains shut in in the aftermath of the hurricane.
It will take a few days for production to be fully restored, according to energy companies with operations in the gulf.
"Once onsite inspections are complete and facilities deemed safe, they will be restarted, and oil and natural gas production will be recommenced in coming days," BP said in a news release. The company said initial aerial inspections showed no significant damage.
The network of platforms, pipelines and storage facilities is massive, however, and exploration and production companies cannot recommence full operations until the chain of energy infrastructure is reconnected.
"Apache personnel are returning to the platforms and inspecting facilities," Bill Mintz, spokesman for Apache Corp., said in an email. "The process of restoring production will take a number of days and will be impacted by the pace of resumption of activities by the pipelines and processing facilities operated by other companies."
The U.S. Bureau of Safety and Environmental Enforcement said reports on offshore facilities indicated mostly minor damage.
In addition to production platforms, the bureau said, 19 of the Gulf's 76 drilling rigs are still evacuated, down from 48 as the storm approached.
A surge in gasoline prices accompanied Isaac, although the dramatic increases came to an end Friday as the storm moved farther inland. The national average price for gasoline inched up just 0.3 cents Friday to $3.83 per gallon.
Pump prices for gasoline were on the rise even before Isaac arrived. The average price for a gallon of gas rose about 40 cents from July 1 to mid-August because of refinery problems in the Midwest and West Coast, and sharply higher crude oil prices.
Crude has traded between $94 and $97 per barrel for two weeks, after rising from a low near $77 in late June.
On Friday U.S benchmark crude rose $1.85 to end at $96.47 per barrel after Federal Reserve Chairman Ben Bernanke made clear in a speech that the central bank can do more to revive the U.S. economy. That would drive up demand for energy.