UPDATE 1-U.S. oil drillers add rigs in Niobrara and Eagle Ford -Baker Hughes
May 22, 2015 at 14:19 PM EDT
May 22 (Reuters) - Oil drillers added rigs in two U.S. shale basins this week, data showed on Friday, the strongest sign yet that higher crude prices are coaxing producers back to the well pad after a slump in activity of nearly six months.