(Bloomberg) -- North Dakota’s Bakken shale field — once the largest and busiest American shale patch — is showing signs of age, threatening to hold back US oil production as the world thirsts for more crude.

Mature wells that are producing more gas than expected are hurting crude output from the Bakken, the Energy Information Administration said in an email Tuesday. The deteriorating performance was a main reason the agency cut its estimate for 2024 US oil output to 12.65 million barrels a day from an earlier projection of 12.8 million.

The weakening production outlook comes as Russia’s war in Ukraine, which has disrupted global supplies, grinds toward its first anniversary. At the same time, the International Energy Agency is forecasting higher global oil consumption as China shows signs of a stronger-than-expected economic recovery. 

Even at the lowered estimate for next year, US output would still set a record, surpassing the 12.3 million barrels a day produced in 2019. 

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