With the introduction of new risk controls, the British government has cleared the way for hydraulic fracturing (fracking) to resume in the country where the shale gas reserve could be 4.2 Tcf, according to one estimate.
Last year the government halted exploratory fracking at a site in northwestern England due to small tremors thought to be associated with the fracking. Cuadrilla Resources Ltd. was drilling on its field near Blackpool, in Lancashire, England. The company has claimed that there may be 200 Tcf of gas in place in the Bowland Basin. Estimates for UK shale gas potential are about 4.2 Tcf (see Shale Daily, Sept. 26, 2011).
"The analysis carried out by Cuadrilla's advisers, and confirmed by our independent panel of experts, has however concluded that the most likely cause of the tremors is the movement of the frack fluid into and along a fault which was already under stress," said Energy and Climate Change Secretary Edward Davey. "The additional pressure of the fluid allowed the fault to move, releasing the energy stored in the fault and resulting in the perceived tremors at the surface."
To move exploration and fracking forward, Britain has instituted controls to mitigate the risk of seismic activity. They include:
The fracking plan should be progressive, starting with the injection of small volumes of fluid and analyzing the resulting data carefully before the full stage, Davey said. "Each stage of the frack will be carefully designed to use just enough fluid to create a fracture sufficient to enable gas to flow, he said. "A flowback period will be required immediately after each stage to rebalance the pressures. Real-time recording of earthquakes during and for 24 hours after each stage of the frack will be analyzed to look for abnormal induced events amidst the normal background seismicity."
Britain has also created the Office of Unconventional Gas and Oil, led by the DECC and will also be tackling the issue of shale gas development and its possible impact on greenhouse gas emissions and climate change, Davey said.
"We are still in the very early stages of shale gas exploration in the UK and it is likely to develop slowly," Davey said. "It is essential that its development should not come at the expense of local communities or the environment. Fracking must be safe and the public must be confident that it is safe. We are strengthening the stringent regime already in place with new controls around seismic risks. And as the industry develops we will remain vigilant to all emerging evidence to ensure fracking is safe and the local environment is protected."
The group Shale Gas Europe welcomed the news that fracking may proceed.
"While there continues to be intense speculation around risks, there is now substantial scientific evidence to support the UK Government's decision, said Shale Gas Europe spokesperson Monica Cristina. "In June 2012 the Royal Society and the Royal Academy of Engineering concluded that the health, safety and environmental risks associated with the [fracking] technique can be effectively managed. There are significant potential opportunities, as the British Geological Survey estimates UK shale gas resources maybe 50% larger than conventional gas resources."