USA crude futures CLc1 settled down $1.97 to $50.44 a barrel, a 3.8 percent drop, the biggest one-day decline since March 8.
The WTI crude oil price and the product spot prices were not available due to the market closure on Friday. Stocks have dropped sharply in the last several weeks and have fallen below levels seen at this time a year ago, but are still higher than where inventories have been in this decade.
Last week the prices of oil had gone past $53 a barrel following the push by some producers to extend the OPEC supply cut deal by the more than 6 months that had been settled on.
West Texas Intermediate crude oil has given up most of its early gains.
Elsewhere in the energy spectrum, May gasoline tacked on 0.4% to $1.666 a gallon and May heating oil edged up by 0.1% to $1.583 a gallon.
Brent crude futures LCOc1 fell 85 cents, or 1.6 percent, to $54.04 a barrel as of 12:31 p.m. EDT, while USA crude futures CLc1 lost 77 cents, or 1.4 percent, to $51.64 a barrel.
James Williams, president of energy consultant WTRG Economics in London, Arkansas, said the minister's bullish statement did not lift prices much because of growing USA shale production.
"The domestic increases continue to not only offset overseas production cuts, but potentially more importantly, they also weigh on OPEC's morale as they are watching market share continue to slip away as a result of their own policy actions", he said in his latest report.
US gasoline stocks posted a counter-seasonal build of 1.5 million barrels, because of rising refining activity.
At an energy conference in Abu Dhabi, Saudi Arabia's energy minister Khalid al-Falih hinted at the extensive behind-the-scenes negotiations among big oil producers ahead of the group's meetings scheduled for May. Despite a drop in USA crude stocks last week, an unexpected 1.5-million-barrel build in gasoline stocks drove prices more than 3.5 percent lower on Wednesday. The industry body American Petroleum Institute had reported an increase of 2.254 million barrels in gasoline inventories on Tuesday, setting the stage for crude's slide.
"Saudi's done a good job of managing the rhetoric", said Michael Hiley, a trader at LPS Futures LLC.
"With questions hanging over US gasoline demand, any further product builds will act as a brake on the oil price recovery", he said.