A fire at a Chevron Corp natural gas well in western Pennsylvania was being left to burn on Wednesday after an explosion early Tuesday left one worker injured and another missing, state officials said. Flames shot from the head of the Lanco 7H well, which is 50 miles south of Pittsburgh in the Marcellus shale region and emergency workers were unable to get near on Wednesday. The fire could continue indefinitely as gas flows up the well from underground, said John Poister, spokesman for the Pennsylvania Department of Environmental Protection. “There’s a large amount of gas in the well, and it could burn, if we just sat there and watched it, for months or years,” Poister said. Chevron said it did not know how long the fire would continue. Putting the flames out will probably involve some sort of smothering, possibly with foam […]