Hurricane Isaac is disrupting crude oil production in the Gulf of Mexico, and may limit about 2% of the United States' refining capacity, at a time when the global fuel market is already under pressure.

According to the National Hurricane Center of the United States, Isaac is approaching the states of Mississippi, Alabama, and the Florida panhandle with the intensity of a Category 3 hurricane, with a maximum sustained wind speed of 120 miles per hour. It is expected to make landfall on Friday night or early Saturday.

As of Thursday, oil companies had ceased production by about 1.3 million barrels per day, which accounts for approximately 63% of the total production in the Gulf of Mexico in the United States, according to data from the U.S. Environmental Protection Agency (EPA).

This hurricane seems to be deviating from the densely populated refining areas in southern Louisiana, near New Orleans and Baton Rouge.

However, the storm may affect Chevron's refinery located in Passagula, Mississippi, as well as the Vertex Energy refinery located in Sullan, Alabama. Andy Ribeau, President of Lipow Oil Associates, stated that both areas are under hurricane warnings, and these facilities combined can produce 466,000 barrels per day, which accounts for 2.4% of the United States' refining capacity.

"Of course, losing any refining capacity is not a good thing when diesel supplies have dropped to their lowest level since the U.S. Energy Information Administration began tracking them in 1982," Lipow wrote in a report on Friday.

Chevron spokesman Ross Allen stated that the company's refinery in Pascoagula was still in operation on Thursday. Vertex was unable to immediately comment on its Salalan refinery.

"The biggest risks faced by these two refineries are power outages or damage from floods," Lipow wrote in his report on Friday. He said that if the refineries stop production without being damaged, it could take one to two weeks to restart them."

Lipo stated that the operating rate of refineries along the Gulf of Mexico coast has reached 95%, so there is not much margin in the system to compensate for the loss of production.

Due to wars in Eastern Europe and the Middle East that have weakened refining capacity, diesel prices have risen significantly. Ukraine's attacks on Russian refineries have forced Moscow to ban diesel exports. Iran and its Houthi allies have also attacked refineries in the Middle East region.

American refiners, taking advantage of the larger profit margins, export diesel to the rest of the world, especially to Europe.

ClearView Energy Partners Kevin Burke, the Managing Director, stated that in the past, during the shutdowns of refineries in the Gulf of Mexico, fuel prices would rise while crude oil prices would fall. This was because these refineries no longer demanded crude oil nor did they produce fuel for consumers, Burke said on Thursday in the program Squawk Box on CNBC.

Libo warned that oil tanker transportation will also be disrupted.

"The shipment of crude oil from tankers to refineries will be delayed, as will the loading of gasoline, aviation fuel, and diesel from refineries by another batch of tankers," said the analyst. "Delays in the receipt of gasoline, aviation fuel, and diesel in Florida are also expected."