Oil prices fell about 1 percent on Monday as signs of a strong recovery in U.S. drilling overshadowed news that OPEC and non-OPEC producers were on track to meet output reduction goals. Ministers representing members of the Organization of the Petroleum Exporting Countries and non-OPEC producers said at a meeting in Vienna on Sunday that of the almost 1.8 million barrels per day they had agreed to remove from the market starting on Jan. 1, 1.5 million bpd had already been cut.