Oil prices dived Friday as traders worried that global supplies exceed the demand.

U.S. oil companies added more oil rigs this week despite the collapse in crude prices.

Data showed a weekly rise of five in the number of active U.S. oil drilling rigs to 664, according to oil services company Baker Hughes' Friday report.

The downbeat earnings of U.S. petroleum giants added woes to the industry.

ExxonMobil, the largest U.S. oil company reported Friday its second-quarter profits fell by 52 percent to 4.2 billion dollars.

Chevron reported about a 90 percent drop in profit, the worst quarterly result in several years.

Traders also anticipated more Iran crude would come to the already well-supplied oil market as the sanctions would be lifted.

The West Texas Intermediate for September delivery moved down 1. 4 U.S. dollars to settle at 47.12 dollars a barrel on the New York Mercantile Exchange, while Brent crude for September delivery decreased 1.1 dollars to close at 52.21 dollars a barrel on the London ICE Future Exchange.