U.S. oil drillers added rigs for the sixth-straight week, marking the longest period of expansion in a year, as the shale patch revives from the worst downturn in a generation. Rigs targeting crude in the U.S. rose by 7 to 381 in the past week, Baker Hughes Inc. said on its website Friday. Explorers have now added 51 rigs since June 24, … Read More