Oil fell on Thursday, pressured by returning Nigerian and Canadian output and as traders looked to book profits ahead of the long holiday weekend in the United States.
Resurgent Nigerian supply will put pressure on prices, Goldman Sachs said, adding that outages caused by Canadian wildfires would virtually end by September.
OPEC's oil output has risen in June to its highest in recent history, a Reuters survey showed, as Nigeria's output partially recovers from militant attacks and Iran and Gulf members boost supplies.
Oil production in Nigeria has risen to about 1.9 million barrels per day (bpd) from 1.6 million, due to repairs and a lack of new major attacks on pipelines in the Delta region, the state oil company said on Monday.
The market was in the midst of a round of profit taking selling ahead of a long holiday weekend in the United States, and trading liquidity was likely to start to decreasing as early as Thursday afternoon, said Dominick Chirichella, senior partner at the Energy Management Institute.