A derrick hand with Raven Drilling in the Bakken Shale formation outside Watford City, N.D…. U.S. oil prices rose on Tuesday, posting a 25% quarterly gain, after Iran and six world powers extended the deadline for nuclear talks until July 7. Prices posted their largest single-quarter percentage gain since 2009 on expectations of a drop in U.S. production and growing demand after slumping to near-six-year lows earlier in the year. So far, however, U.S. oil output hasn’t slowed, and prices have stabilized around $60 a barrel in recent weeks as traders looked for direction. The U.S. benchmark fell 1.4% this month. The Iranian talks, aimed at blocking the country’s path to a nuclear weapon in exchange for lifting international sanctions, could eventually allow Iran to increase its oil exports. A failure to reach a deal would be supportive for oil prices, because it would keep hundreds of thousands of […]