About 25, 000 wells a year are being fracked, a process in which water, chemicals and sand are injected at high pressure underground to release trapped natural gas.
The process involves pumping water containing small percentages of other materials into the porous shale under pressure to hydraulically fracture it and release the trapped oil and gas.
Having achieved his run landmark in only his 60th Test, Pietersen gave a catch to extra cover off Shakib's slow left-arm and the pressure increased in the next over when Paul Collingwood was trapped lbw on the crease by Hossain.