U.S. shale producers are returning to unfinished business – completing previously drilled wells – offering a ray of hope for oilfield service providers battered by the oil slump. Halliburton Co and Baker Hughes Inc, the world’s second and third-largest oilfield services companies, indicated on Tuesday that they expected a drop in the large number of drilled-but-uncompleted wells (DUCs) as crude oil prices steady. Oil is hovering above the $40/barrel mark after having rallied 20 percent in the past month. This has been enough for several producers to return to the thousands of unfinished wells that dot shale fields across the United States – essentially to ready them for production. Devon Energy Corp, Diamondback Energy Inc and SM Energy Co all said on post-earnings calls on Wednesday that they were completing more wells. […]