Oil markets were volatile as the week began as the unprecedented storm Harvey took its toll on America's refining industry along the Gulf Coast.
The hurricane has been the most powerful to hit the state of Texas in half a century, causing massive floods, killing at least two and leaving 300,000 customers without electricity.
It came as 25 inches of rain fell over two days - over half its annual rainfall normally.
Federal officials predict it will drive 30,000 people into shelters and trigger 450,000 people to seek some kind of assistance.
As refineries in the Houstin area were forced to close, gasoline futures reached two year highs but US crude futures fell as shutdowns caused a potential slackening of demand.
On the Intercontinental Exchange (ICE), futures for West Texas Intermediate, for October delivery, were down 0.86% at the time of writing at $47.46.
Gasoline futures however, for September delivery, were up 1.23%.
Brent crude for October is up 0.076% to $52.45 a barrel.
Exxon Mobil Corp (NYSE:XOM) has the US's second-biggest refinery in the Houston area, processing as much as 560,000 barrels of oil a day and feeding pipelines and barges that move it across the southeastern US and up the East Coast.