Below is a sampling of statistics on refinery capacity in different states starting from 0 in Florida, for example to Texas, which has the greatest refinery capacity. Louisiana refines a lot of oil. I don't know how much of it might be affected by Katrina. (I also don't know what effect Katrina might have on the offshore drilling in the area if any.
Refineries: There are no refineries located in Florida.
Refineries: Operable distillation capacity of 113,500 Barrels Per Calendar Day (BCD) (2005)
Refineries: Distillation capacity of 364,800 Barrels Per Calendar Day (BCD) (2005)
Refineries: Distillation capacity of 373,500 Barrels Per Calendar Day (BCD) (2005) (ranked second in production of oil)
Refineries: Distillation capacity of 484,961 Barrels Per Calendar Day (BCD) (2005)
Refineries: Distillation capacity of 551,400 Barrels Per Calendar Day (BCD) (2005)
Refineries: Distillation capacity of 2,004,788 Barrels Per Calendar Day (BCD) (2005) (ranked 4th in production of oil including offshore)
Refineries: Distillation capacity of 2,772,723 Barrels Per Calendar Day (BCD) (2005) (ranked 5th in oil production including offshore)
Refineries: Distillation capacity of 4,627,611 Barrels Per Calendar Day (BCD) (2005) (ranked first in production of oil)
http://tonto.eia.doe.gov/oog/info/state/la.html