AT&T has LTE in Fourchon now.
I don’t know about other prepaid plans, but Boost Mobile (Sprint) did not work on Petrocom. That was in 2010.
After buying a new IPhone 5, I thought I would be getting better internet speeds down in Fourchon. Turns out, AT&T has LTE down here, but not 4G LTE. Not sure the difference. After calling them, they said installation of a fiber-optic cable should be complete near the end of January and after that, 4G LTE users should see the significant increase in data speeds (15-25 mbs).