Hurricane Harvey on Friday slammed the epicenter of Texas' refining industry, which processes about a third of America's oil.
Companies including Exxon Mobil and Valero Energy have shut down their facilities in the area and evacuated workers.
Goldman Sachs estimates that the hurricane has taken 3 million barrels a day — or about 17% — of refining capacity offline, and that's likely to increase the overall level of crude-oil inventories over the next couple of months.