Front-month U.S. West Texas Intermediate (WTI) crude futures were up 30 cents, or 0.45 percent, at 0651 GMT, at $66.73 per barrel.
More output by members of OPEC the Organization of Petroleum Countries was able to offset the seasonal declines by non-OPEC members, though supply from non-OPEC nations was up as well by 2.6 million barrels per day, led by the United States.
At the same time, August saw the crude supply for OPEC hit a high of nine months of 32.62 million barrels per day despite worries over dropping production and slashed access from big producers Iran and Venezuela.
Brent rude prices fell in August however extra fair lately rose to 2-month highs round $eighty a barrel.
But it said rising demand could also be checked.
Latest reports suggest that Iran has begun to store oil in its own tankers off its coasts ahead of the United States sanctions.
Oil prices held firm on Tuesday, with USA fuel markets seen to be tightening, although the release of crude from the American strategic reserve somewhat offset an expected supply cut due to upcoming sanctions against Iran.
US light crude fell $1.15 to a low of $69.22 a barrel and was last at $69.50, down 87 cents. The increase was driven by higher output in Libya, Iraq and Nigeria.
Distillate stockpiles, which include diesel and heating oil, rose by 6.2 million barrels, versus expectations for a 1.4 million-barrel increase, the EIA data showed.
The OPEC said the price of its basket went up by $0.82 on Tuesday, compared with the closing price at the previous session, Efe news reported. The sanctions will target Iran's oil exports from November.
Outside the United States, traders have been focusing on the impact of US sanctions against Iran that will target oil exports from November.
That price range could be "tested" as the oil market enters "a very crucial period", the Paris-based agency said in its monthly report.
"We can see that the pricing situation today depends not just on the supply/demand balance or the general economic situation but also on the uncertainty that we observe today in the global markets: the trade wars, the sanctions that the USA pursues", Novak told CNBC.
"Going forward, economic uncertainty, and hence questions surrounding global oil demand, coupled with geopolitical tensions, will need to be factored into maintaining a balanced market in the months to come", the report said.
"As we move into 2019, a possible risk to our forecast lies in some key emerging economies, partly due to currency depreciations versus the USA dollar, raising the cost of imported energy", the agency said.
That month Russian Federation produced 11.247 million barrels per day, a post-Soviet Union record high.