The plunge in U.S. oil prices has wells in some parts of the Permian Basin below break-even levels, threatening to put the brakes on the record flow from the prolific field. Oil produced from the Permian in Midland, Texas, is now trading below $40 a barrel for the first time since August 2016, according to data compiled by Bloomberg, as West Texas Intermediate futures dropped more than 6 percent Tuesday. U.S. oil production is set to rise by 1.18 million barrels a day to 12.06 million next year, according to a U.S. government forecast , with Permian growth expected to lead the way. While U.S. shale producers could make money at $50 oil, industry analysts say, sub $40 oil may be a different story. Breakevens for new wells among various counties in the Spraberry area currently average between $32 to $47 a barrel, according to Bloomberg NEF data . […]