Lorries transport the gas to market.
Energy companies drill holes around 1.5 miles deep.Conductors send electrical currents into theMarcellus shale.
They remove the fracturing fluid, and sand keepsthe fissures open.
The electricity causes the shale to fracture.
Machines inject fracturing fluid into the bore hole.
The natural gas flows to the surface and containerscollect it.
The fracturing fluid makes the fissures expand.