Around 3,000 platforms are thought to be affected by the outage - although it seems likely that refineries along the Texas coast will be missed by the storm.
New Orleans has already been largely evacuated in anticipation of the hurricane's approach.
The tropical storm has already caused severe damage to properties in several Caribbean islands, including Cuba.
Oil from the Gulf accounts for around one in four barrels produced by the US, as well as 15 per cent of national natural gas output.
Spikes in wholesale prices were noted on the global markets following Hurricanes Katrina and Rita during storm season three years ago.
Crude oil on the New York Mercantile Exchange increased in price by 72 cents to hit $116.18 a barrel yesterday.
However, the price fell back to $114.86 a barrel this morning, as new metrological data showed that the storm was not strengthening.