U.S. oil explorers idled oil rigs for the 14th straight week, prolonging the biggest retrenchment in drilling on record. Rigs targeting oil in the U.S. fell by 56 to 866, Baker Hughes Inc. said on its website Friday, the lowest level since March 25, 2011. The Permian Basin of Texas and New Mexico, the nation’s biggest oil field and one of its oldest, lost the most, dropping 23 rigs to 305. The U.S. rig total slid to the lowest since November 2009. The country has sidelined 709 oil rigs in 14 weeks as a price collapse has prompted the nation’s energy producers to cut billions in spending and eliminate thousands of jobs. The retrenchment threatens to slow the shale boom that turned the U.S. into the world’s largest fuel exporter. Oil analysts, traders and investors have been monitoring rig counts to determine when output will retreat enough […]