U.S. oil explorers idled rigs for the 12th straight week, extending the steepest dropoff in drilling on record as crude prices headed for a second week of losses. Rigs targeting oil in the U.S. fell by 33 to 986, dropping below 1,000 for the first time since June 2011, Baker Hughes Inc. said on its website Friday. Those seeking gas dropped by nine to 280, the Houston-based field services company said. The total U.S. count declined by 43 to 1,267, including a miscellaneous rig. The U.S. has lost more than a third of its oil rigs over four months in an unprecedented retrenchment in drilling that threatens to bring the nation’s shale boom to a halt as early as this year. Collapsing oil prices have already wiped out thousands of U.S. jobs and dried up more than $86 billion in capital […]