By Stephanie Kelly NEW YORK (Reuters) -Oil prices tumbled more than 6% to their lowest in almost three weeks on Tuesday as supply disruption fears eased and surging COVID-19 cases in China spurred demand concerns. Brent futures plummeted $6.99, or 6.5%, to settle at $99.91 a barrel, while U.S. West Texas Intermediate (WTI) crude fell $6.57, or 6.4%, to settle at $96.44 a barrel. Both contracts settled below $100 per barrel for the first time since late February. Brent fell as low as $97.44 during Tuesday’s session and WTI hit $93.53, their lowest since Feb. 25. Both contracts moved the closest…