Oil prices jumped 6 percent on Wednesday, snapping a two-day rout, after investors took advantage of a weaker U.S. dollar and shrugged off data showing a unexpected large surge in U.S. crude inventories to record highs. The dollar index tumbled to an over seven-week low amid growing skepticism that the Federal Reserve would be able to hike U.S. interest rates again this year and after data showed the U.S. services industry grew more slowly than expected last month. U.S. crude futures rose $1.96, or 6.5 percent, to $31.84, after touching a high of $31.95.