I haven't seen Gasland, but understand the basic fracing procedure: Pump liquid down a hole at high pressure, and "Fracture" the underlying formation.
Pretty much.
Samson said:Generally the stimulation technique is used on older wells, which comprise most plays in the USA, including Pennsylvania where a couple of producers have been shut down because of groundwater contamination issues, real or imagined.
There are environmentally friendly alternatives...ClO2 comes to mind, but it is not as easy to apply as dumping a bunch of HF down hole.
Stimulation is used on brand new wells, part of the primary completion. They use it in all sorts of low permeability rock, which are the unconventional resources like the shales of the Bakken (oil) and Barnett (gas). It is quite possible for a wells construction to be compromised in some way, leading to all sorts of bad secondary effects. However, state well design requirements require freshwater protection as a matter of course, if something bad happens, the companies are required (and are well equipped) to handle it.