The latest data from the Energy Information Administration showed that US crude oil inventories rose by 2.5 million barrels in the week ending July 17.
That brought the total number of barrels to 463.9 million, keeping stockpiles at an 80-year high for this time of year.
Last week's data showed a drop in inventories by 4.3 million barrels after a two-week build.
Ahead of the release on Wednesday, West Texas Intermediate crude oil fell below $50 per barrel again, after crossing the mark on Monday. Following the release, WTI was down nearly 2% at around $49.94 per barrel.
On Tuesday, the American Petroleum Institute reported further signs of a supply glut, with its data showing a build of 2.3 million barrels last week, exceeding analyst estimates of 1.9 million.
Here's how crude oil has traded over the past couple of days:
Finviz