They came to Pittsburgh, and the Marcellus shale was the lure. Some 1,400 people attended our "Developing Unconventional Gas-East" (DUG-East), held October 19. One key take-away is that the Marcellus may be the largest natural gas field in North America (just give it a few more years of steady development drilling), and in fact, it might rank among the top five gas fields in the world. Estimates put the recoverable gas reserves at anywhere from 250- to 489 trillion cubic feet! It's still early in the game, however, so as time goes on, those numbers will likely rise. No doubt the play will evolve into several separately named, but adjacent fields, rather than calling an entire swath of the eastern U.S. one big field. By comparison, the Tamar Field just unveiled offshore Israel, which has operator Noble Energy Inc. and plenty of others, excited, has about 6.3 Tcf recoverable. The famed Madden Field in Wyoming has about 4 Tcf. Another key take-away is that industry appears to be solving any water-related challenges, despite the fears of regulators and environmentalists in the region. Sourcing enough water for the multi-stage frac jobs being done is not a problem, and handling the produced water may not be either. Range Resources Corp., a play leader that drilled the first slick-water-fraced Marcellus well in 2004, is close to having zero-discharge wells as it treats and recycles produced and frac-water. At present, the industry has dodged a bullet--the Pennsylvania legislature did not impose a severance tax on natural gas production as part of the new state budget just signed by Gov. Ed Rendell. Meanwhile, despite fairly low gas prices, activity ploughs ahead. There are 650 horizontal wells permitted in Pennsylvania's top-five most active counties: Greene, Tioga, Washington, Susquehanna and Bradford. For much more on the Marcellus shale, and to see videos of key speakers at DUG-East, go to and --Leslie Haines