Hurricane Harvey has shut down more than 16 per cent of the US oil refining capacity as record rain and flooding battered Texas today.
Supply shortages have sprung up as the tropical storm moved up the Gulf Coast, with pipelines lowering deliveries or shutting down completely due to low supply.
Around three million barrels per day (bpd) of refining capacity has been closed off already, and rebooting the plants is expected to week or more.
More refinery closures are expected to take place, with possible implications for oil prices.
Explorer Pipeline, which runs between Texas and Chicago, will close down two of its lines on Wednesday.
Motiva Enterprises warned it may decide to close the Port Arthur refinery, which is the biggest in the country.
High water in the refinery, which produces 603,000 bpd, was causing operational problems, Reuters reported. Water had submerged the pumps responsible for clearing waste water from the crude distillation units.
Flooding also prompted Marathon Petroleum Corporation to close two of its refineries near Houston.