Wall Street’s oil analysts are getting harder to impress. After two straight quarters when the U.S. shale industry posted outsized oil production figures that clobbered expectations, explorers are finding it more difficult to be overachievers. Once-innovative engineering tricks such as drilling two-mile long sideways wells and cracking the rocks with mountains of sand are becoming routine, depriving oil companies of methods to deliver shockingly big output numbers. For every third-quarter outperformer like Marathon Oil Corp. or Chesapeake Energy Corp., there have been production duds such as Cimarex Energy Co. and Rice Energy Inc., which were slammed by investors on Thursday after their output fell short of analysts’ targets. Cimarex tumbled as much as 7.6 percent for its worst intraday loss in eight months after reporting an output miss; Rice fell as much as 2.6 percent. “Whereas in the last couple of quarters, everybody smoked expectations, now we’re starting to […]