Production from shale formations in the United States, which has led to an unexpected reversal in long declining oil output, will peak at 4.8 million barrels per day (bpd) in 2021, according to an Energy Information Administration forecast issued on Monday. This year is the bumper year for production out of the tightly packed shale rock. Output should rise by 1.2 million bpd, the highest annual jump, to 3.5 million bpd this year, according to tables in the EIA’s Annual Energy Outlook. Production will exceed 4 million bpd next year and rise more gradually toward its peak. It will fall to 3.2 million bpd by 2040. Last year, the EIA expected shale oil production to peak in 2020 at 2.8 million bpd with this year’s production at 2.3 million bpd. (Reporting by Sabina Zawadzki; Editing by Bob Burgdorfer)