USA light crude was 25 cents lower at $65.49.
This would have reduced supply in the open market and driven prices higher.
Oil prices fell on Friday, extending losses as JP Morgan cut its crude price forecast, after already weakening on concerns about surging USA output weighed and falling demand in China.
JP Morgan cut its 2018 crude forecast for WTI by $3 to $62.20 a barrel, traders said.
"Non-OPEC supply is expected to rise sharply in 2019 led by U.S. shale growth, along with Russia, Brazil, Canada and Kazakhstan", U.S. bank JP Morgan said, adding that it was bearish for oil in the second half of this year.
The price of Brent crude rose Wednesday after output from OPEC member Venezuela came into renewed doubt, enhancing worries over global supply.
The futures contracts dipped after the forecast was issued, and then pared losses.
Prices were weighed down by another rise in the number of rigs drilling for new oil production in the United States, which crept up by one to reach its highest level since March, 2015 at 862, according to energy services firm Baker Hughes on Friday.
Oil prices were mixed on Monday, caught between the downward pull of rising Russian production and US oil drilling activity at its highest since 2015, and upward pressure from strong demand, especially in Asia. Tankers waiting to load more than 24 million barrels of crude, nearly as much as PDVSA shipped in April, are sitting off the main oil port, according to shipping data.
Analysts expect higher US output to offset supply curbs by the Organization of the Petroleum Exporting Countries, which have been in place for 18 months and have pushed up prices significantly over the previous year.
Russian news agency Interfax said on Saturday that the country's production had surpassed its target, hitting 11.1 million bpd in early June.
Despite Friday's decline, Brent remains more than 15 percent above its level at the start of the year.
Markets have been tightened by supply trouble in Venezuela, where state-owned oil company PDVSA is struggling to clear a backlog of about 24 million barrels of crude waiting to be shipped to customers.
OPEC member Venezuela, threatened with US sanctions in the midst of an economic crisis, is almost a month behind delivering crude to customers from its main export terminals, according to shipping data. That leaves investors looking ahead to a coming meeting of the Organization of the Petroleum Exporting Countries on June 22, which could determine whether a mostly upward trend for crude continues.
OPEC and Russian Federation are due to meet at the organization's headquarters in Vienna on June 22 to discuss production policy.
"We're going to be subject to incredible headline risk", New York-based hedge fund Again Capital LLC partner John Kilduff said.