US drillers added oil rigs for the first time in three weeks, increasing the rig count by 2 to 862.
The reversal in oil prices from early July highs was triggered by easing threats of the tropical storm Gordon hitting the Gulf of Mexico.
International Brent crude futures LCOc1 , by contrast, lost ground, trading at $78.10 per barrel, down 5 cents from their last close.
At the end of last month, Iran's Foreign Minister was quoted as reminding the European Union that Iran was still waiting to receive guarantees that the EU would continue to buy Iranian oil even after USA sanctions kick in on November 4.
"It has a lot to do with just lots of positive sentiment in the oil speculator market", said Rob Haworth, who helps oversee $151 billion at US Bank Wealth Management in Seattle.
Now add to that group Iraq, which is ready to ship more crude as soon as OPEC reaches an agreement on how members will share a collective supply boost, Alaa Al-Yasiri, acting director-general of the state-run Oil Marketing Co., said Wednesday.
Oil production is rising all across the top producers.
According to Stephen Innes, Asia-Pacific brokerage OANDA's head of trading, the Brent crude oil benchmark's price rise has been supported by the expectation that the upcoming United States sanctions are going to lead to constrained markets across the globe.
India is allowing state refiners to import Iranian oil with Tehran arranging tankers and insurance after firms including the country's top shipper Shipping Corp of India (SCI) halted voyages to Iran due to US sanctions, sources said.
In a speech on June 4, the Leader slammed European governments for expecting the Iranian nation to both tolerate sanctions and give up its nuclear activities, saying that the country can not remain in "nuclear custody" when the sanctions are still in place.
Resource-pour Japan relies heavily on imports of oil from the Middle East, though crude from Iran accounted for just 5.3 percent of the country's total imports previous year.
The economists said: "The EU, Korea, Japan and UAE collectively accounted for 41 percent of the average 2.6million barrels per day Iran exported in the first half of 2018".
Still, worries persist that the market is due for a tightening anyway: Stephen Innes, head of trading for Asia-Pacific at OANDA, said Brent was "supported by the notion that US sanctions on Iranian crude oil exports will eventually lead to constricted markets".