LONDON—Oil slipped on Monday in volatile trading as the release of strategic reserves by consuming nations eased concerns over tight supply amid Russia’s invasion of Ukraine and the lack of an Iranian nuclear deal. Crude dropped by about 13 percent last week after President Joe Biden announced a record U.S. oil reserves release and as International Energy Agency members committed to further tapping reserves. Crude had hit $139 last month, its highest since 2008. “The massive release of 1 million barrels per day over a period of six months in the United States alone is likely to ensure that the oil market is no longer acutely undersupplied in the second and third quarters,” Carsten Fritsch of Commerzbank wrote in a report. Brent crude was down 67 cents, or 0.6 percent, at $103.72 a barrel by 1010 GMT. U.S. West Texas Intermediate crude fell 57 cents, or 0.6 percent, to $98.70. …