Oil prices surged Friday as the dollar weakened and the number of rigs drilling for oil in the U.S. fell for a 15th straight week . The expiration of the front-month U.S. oil-futures contract extended the move, analysts said, as traders closed out positions. Light, sweet crude for April delivery rose $1.76, or 4%, to $45.72 a barrel on the New York Mercantile Exchange, posting the largest one-day move since Feb. 12. Prices gained 2% on the week, snapping a four-week losing streak. The April contract expired at settlement Friday. The more-actively traded May contract settled up $1.04, or 2.3%, at $46.57 a barrel. Brent, the global benchmark, rose 89 cents, […]