The path toward U.S. energy independence, made possible by a boom in shale oil, will be much harder than it seems. Just a few of the roadblocks: Independent producers will spend $1.50 drilling this year for every dollar they get back. Shale output drops faster than production from conventional methods. It will take 2,500 new wells a year just to sustain output of 1 million barrels a day in North Dakota’s Bakken shale, according to the Paris-based International Energy Agency . Iraq could do the same with 60. Consider Sanchez Energy Corp. (SN) The Houston-based company plans to spend as much as $600 million this year, almost double its estimated 2013 revenue, on the Eagle Ford shale formation in south Texas, which along with North Dakota is one of the hotbeds of a drilling frenzy that’s pushed U.S. crude output to the highest in almost 26 […]