U.S. oil drillers, facing prices that have fallen below $60 a barrel and escalating competition from suppliers abroad, idled the most rigs in almost two years. Rigs targeting oil dropped by 29 this week to 1,546, the lowest level since June and the biggest decline since December 2012, Houston-based field services company Baker Hughes Inc. (BHI) said on its website today. As OPEC resists calls to cut output, U.S. producers including ConocoPhillips and Oasis Petroleum Inc. (OAS) have curbed spending. Chevron Corp. (CVX) put its annual capital spending plan on hold until next year. The number of rigs targeting U.S. oil is sliding from a record 1,609 following a $50-a-barrel drop in global prices, threatening to slow the shale-drilling boom that has propelled domestic production to the highest level in three decades. “It’s starting,” Robert Mackenzie, oil-field services analyst at Iberia Capital Partners LLC, said by telephone from New […]