Chevron Corp.’s exploration failure rate almost doubled last year as the second-largest U.S. energy producer shifted more drilling efforts to American fields from other parts of the world. Dry holes, or exploratory wells where commercially viable quantities of oil or natural gas weren’t found, represented 30 percent of the total drilled last year, up from 18 percent in 2013, the company said Friday in a public filing. Chevron plans to quit searching Romania’s shale fields this year after abandoning Polish and Ukrainian prospects in 2014. Chevron is accelerating spending cuts that got underway last year as falling crude prices eroded cash available for exploratory drilling, platform construction and other capital projects. The San Ramon, California-based company last month said it plans to reduce outlays by 13 percent this year to $35 billion, more than three times the 3.7 percent cut during 2014. The oil and gas producer […]