VIENNA — OPEC and other oil nations meeting Thursday were set to extend their production cuts in an effort to shore up prices. But the intended impact could be short-lived.

That’s because of U.S. shale producers. With crude prices above $50 a barrel from lows of last year, they are increasingly moving back into the market. Their output already is partially offsetting the cuts, and even more U.S. companies are poised to return if prices rise further.

The upshot is that the price of oil – and derived products like fuel – is unlikely to increase much in coming months, analysts say. That will be welcome news to consumers and energy-hungry businesses worldwide but could continue to strain the budgets of some of the more economically-troubled oil-producing nations, such as Venezuela and Brazil.

The latest reductions have been in effect since November, when OPEC agreed to cut production by 1.2 million barrels a day. Non-OPEC countries led by Russia chipped in with a further 600,000-barrel reduction.

With the deal due to expire at the end of June, one participant said the group had opted for a nine-month extension.

Earlier, Saudi Oil Minister Khalid A. Al-Falih spoke of a “9-month straight” extension going into the meeting. Iran’s Bijan Namdar Zanganeh floated possible extensions of three months, six months or even a year and said his country had “no difficulty” with any of the options, while Jabbar Ali Hussein Al-Luiebi, his Iraqi counterpart, mentioned “the scenario of a nine-month freeze.”