HOUSTON—U.S. shale producers are unlikely to replace banned Russian oil imports due to a shortage of oilfield materials, equipment, and labor and a dwindling backlog of wells waiting to be completed, energy executives and analysts said on Tuesday. President Joe Biden imposed an immediate ban on Tuesday on Russian oil imports in retaliation for its invasion of Ukraine, putting a spotlight on shale producers’ ability to boost output to make up for the loss of about 200,000 barrels per day of Russian crude typically imported by domestic refiners. Shale has a short-cycle—able to add or reduce production relatively quickly—and in the past, producers have delivered explosive growth when prices allow. In the Permian Basin, the top U.S. shale field, output jumped by 100,000 bpd nearly every month in 2018, according to U.S. government data. But unlike 2018, there is a lack of oilfield materials, equipment, and labor, and the fastest …