OPEC may get its members to agree to continue to tamp down oil production, but it will be a Pyrrhic victory. The biggest threat to the 13-member group’s dominance has been U.S. shale. In November 2014, the Organization of Petroleum Exporting Countries decided to keep production levels high in the hope it could maintain market share. But that was a difficult task to begin with, and since then, U.S. shale producers have become even more efficient. By the time OPEC reversed course in November 2016, sending oil prices up as much as 10 percent, shale had already gained ground. There are areas in the enormous Permian and Eagle Ford shale fields in Texas where producers can break even at prices as low as $34 a barrel, according to Bloomberg Intelligence. And analysts now say U.S. shale production will grow even faster than expected. Macquarie Group now thinks production will increase 1.4 million barrels a day through December, up from a previous growth estimate of 0.9 million barrels a day. JPMorgan Chase & Co. doubled its forecast to an increase of 800,000 barrels a day for the same period. As OPEC and non-OPEC producers (namely Russia) cut back on production, U.S. shale producers are moving to quickly fill the gap. Their output increase is equal to about half of the OPEC cuts and twice that of Russia’s cuts, according to a report out this week by Eugen Weinberg, head of commodity research at Commerzbank. “If the production cuts were to be extended, the participating countries would lose further market shares, which they are hardly likely to accept for any length of time,” the report said. It isn’t going to get a lot better for OPEC in 2018, either. JPMorgan is forecasting U.S. shale to grow by 1.05 million barrels a day next year, while Bank of America Merrill Lynch has a figure of 950,000 barrels a day. Even a “drastic” downward shift in the market conditions won’t lead to a rapid collapse of U.S. oil production, according to Rystad Energy. Many wells that have been drilled—but haven’t been completed—could still be brought online profitably if the price falls to $40 or even $30 a barrel, Rystad said in a report on May 11.