Brent crude was also up, hitting a high of $49.26.
Data from the American Petroleum Institute showed that US crude stocks dropped by 5.1m barrels to 536.8m - double the expectations of analysts polled by Reuters.
Inventories were hit by falling imports due to wildfires in Canada, which led to a loss of about 1.5m barrels a day in production, according to OptionsXpress analyst Ben Le Brun.
The oil price could surge past the $50 mark if the data is confirmed when the US Energy Information Administration issues its official inventory figures today.
"Technically, the market is gearing up for WTI to go above $50 a barrel and it is intriguing on where it goes from there," said Le Brun.
"I think the cap is not too far above that level - the world is still awash with oil even if it is off the peaks."