There's been plenty of debate over the Marcellus Shale natural gas field, but new research adds a twist that could impact political and environmental battles.
 
Two independent financial firms say the Marcellus isn't just the biggest natural gas field in the country - it's the cheapest place for energy companies to drill.
 
One of the reports adds that the Marcellus reserves that lie below parts of Pennsylvania, West Virginia, Ohio and New York are far larger than recent government estimates, while another said the powerful combination of resource, cost and location is altering natural gas prices and market trends across the nation.
 
The Marcellus could contain "almost half of the current proven natural gas reserves in the U.S," a report from Standard & Poor's issued this week said.