Oil markets were roiled today after Hurricane Harvey wreaked havoc along the US Gulf coast over the weekend, knocking out numerous refineries and some crude production.

Gasoline prices hit two-year highs as massive floods caused by the storm forced refineries across the US Gulf Coast to shut down.

In crude markets, Brent futures were pushed up by pipeline blockades in Libya, but US crude futures eased as the US refinery shutdowns could reduce demand for American crude.

Harvey came ashore over the weekend as the most powerful hurricane to hit Texas in more than 50 years, killing at least two people, causing large-scale flooding, and forcing the closure of Houston port as well as several refineries.

The US National Hurricane Center (NHC) said today that Harvey was moving away from the coast but was expected to linger close to the shore through Tuesday, and that floods would spread from Texas eastward to Louisiana.

Texas is home to 5.6 million barrels of refining capacity per day, and Louisiana has 3.3 million barrels. Over 2 million barrels per day (bpd) of refining capacity were estimated to be offline as a result of the storm.

Spot prices for US gasoline futures surged 7% to a peak of $1.7799 per gallon, the highest level since late July 2015, before easing slightly to $1.7622 by 0358 GMT.

Flooding is the most urgent problem in Texas. Photo: Reuters

To avoid a fuel shortage, US traders were seeking oil product cargoes from North Asia, several refining and shipping sources told Reuters today.

"There may be meaningful and long-term damage to Texas' refining capacity," said Jeffrey Halley, analyst at futures brokerage OANDA.

Crude production was also affected, but to a lesser degree.

About 22%, or 379,000 bpd, of Gulf production was idled due to the storm as of Sunday afternoon, according to the US Bureau of Safety and Environmental Enforcement. There may also be around 300,000 bpd of onshore US production shut in, trading sources said.

In international oil markets, Brent crude was stronger at $52.58 per barrel, up 17 cents, or 0.3% as Libyan pipeline blockades prevented three oilfields from supplying crude.

These opposing price movements pushed the WTI discount versus Brent to as much as $4.99 per barrel, the widest in two years.

Although the full extent of the storm's damage is not yet clear, some analysts said the impact would be felt globally and affect energy markets for weeks.