Ask those who have tried to produce natural gas from shale formations, and they'll tell you: One size doesn't fit all. Conditions vary—not just from region to region, but from field to field, formation to formation, and, occasionally, from well to well. Much of what works in the Barnett shale, for example, will not work in the Marcellus. Climate, temperatures, and topography can pose unique challenges. So can local inexperience with the oil and gas industry. Executives from two companies delivered that message to an Oct. 20 US Energy Association seminar about the infrastructure, workforce, and environmental challenges of bringing Marcellus shale gas to market. About the same time, the US ...