Though Chinese economic concerns are lingering on the horizon, crude oil prices again recovered on easing worries over Greek debt and Iranian nuclear deals.

Crude oil prices dove around 5 percent earlier this week amid concerns Greek debt crises could spill over again into the broader European economy. Concerns about the expiration of a deadline to reach a final nuclear deal with Iran, meanwhile, were allayed when negotiators agreed to pull up their collective chairs through the end of the week.

Oil prices increased in early Wednesday trading as broader concerns in Central Asia and Europe eased. West Texas Intermediate, the U.S. benchmark, increased only modestly from the previous close to $52.58 per barrel. Brent crude oil gained 1.2 percent in early trading to $57.54 per barrel.

The majority of Greek voters said no in a referendum to help from European and international lenders. Greek debt cast a shadow over the latest international financial crisis, though European leaders said the region's economy would be able to weather the storm.

German Chancellor Angela Merkel said negotiators would try again during the coming weekend to reach a deal, but cautioned the protracted "situation is comparatively serious," calling on the Greek government to provide "extremely detailed proposals" for assistance.

Negotiators in Vienna, meanwhile, agreed to extend talks with Iran to Friday in an effort to formalize a deal that would slow nuclear progress in exchange for sanctions relief. U.S. State Department spokesman John Kirby said during a regular press briefing parties were "just going to keep hammering away at" reaching a final deal.

A deal could put more of Iran's crude oil on an already oversupplied market, though a full return may be a way off.

China's Shanghai Index, meanwhile, continued its steep decline Wednesday, falling nearly 6 percent at the closing bell. China's official Xinhua News Agency described the drops as "massive," noting the central People's Bank of China was actively working to shore up investor confidence.

China's is a world-leading economy and oil consumer, whose appetite could swing oil prices considerably. In its latest forecast, the U.S. Energy Information Administration said it expected Brent crude oil prices to average $60 per barrel for the year.