Herbst stressed the assessments were preliminary, but the damage appeared far worse than that caused by Hurricane Gustav two weeks ago.
Specifics about the size and production capacity of the destroyed platforms were not immediately available.
There are about 3,800 production platforms in the Gulf, including 717 with full-time staffs aboard.
The MMS says Hurricane Katrina destroyed 44 platforms three years ago, and soon after Hurricane Rita destroyed 64.