NEW ORLEANS (AP) — More crews are returning to offshore drilling rigs and production platforms as the weather clears after Isaac.

The federal Bureau of Safety and Environmental Enforcement says crews returned to 86 production platforms between 11:30 a.m. Saturday and the same time Sunday, leaving 131 unstaffed. That compares to 219 vacant Saturday and 499 early last week. Those still unstaffed are about 22 percent of the total.

The agency says 71.5 percent of the Gulf of Mexico's daily oil production and 55.6 percent of its natural gas remain shut-in.

Companies operating in the gulf say it takes a few days to fully restore production.

Workers remain evacuated from 18 rigs, or just under one quarter of those operating in the gulf. Forty-eight were evacuated as the storm approached.