You’d be forgiven for thinking that it’s smooth sailing ahead for the OPEC+ oil producer group.

The 23 members concluded their recent meeting in less than an hour, agreeing to raise output again in October. There were no signs of the tensions that had marred earlier gatherings, just a quick rubber-stamping of the next step in a deal thrashed out in July, which sees the group adding 400,000 barrels a day to supply each month.

But the easy days are numbered. The group’s own analysis of the oil market next year suggests there are still challenges to overcome. Producers, who are finally seeing the benefit of the sacrifices they made last year, may have to forgo future output increases, and perhaps even reimpose cuts, if they are to prevent stockpiles from rising again.