Cabot Oil & Gas had the most productive gas well in the U.S. last year, in Susquehanna County, Pa., yielding 30.3 million cubic feet a day Getty Images Skeptics of the U.S. energy boom say it can’t last much longer because it requires drilling an ever-increasing number of wells. But the boom already has lasted longer than anyone would have imagined just a decade ago and has more room to run. That’s because oil and natural-gas wells have become more productive—an unrecognized but potent trend that should keep the fuels flowing. Back in 2003, the energy industry had just begun combining the techniques of drilling horizontal bores through shale and then using hydraulic fracturing—shooting tons of water, chemicals and sand into the rocks. Four Sevens Oil Co. drilled the best gas well that year, in the Barnett Shale, just north of Fort Worth, Texas, according to Drillinginfo, an industry […]