From The New York Times – June 6, 2011

by David Jolly

PARIS — A British company said Wednesday that it would temporarily halt
the use of a controversial gas exploration technology after indications
that it might have set off two small earthquakes near a test well in
Lancashire, England.

The company, Cuadrilla Resources,
which is exploring for gas in shale formations deep underground, said
it would postpone hydraulic fracturing, or fracking, operations at the
Preese Hall site near Weeton.

“We take our responsibilities very seriously,” Mark Miller, the chief
executive of Cuadrilla, said in a statement, “and that is why we have
stopped fracking operations, to share information and consult with the
relevant authorities and other experts.”

Fracking is a procedure in which water, chemicals and sand are injected deep underground to free oil or gas trapped in dense shale formations.

The technology is widely used in the United States, where it has contributed to a boom in natural gas
production. It has been criticized because the fracking chemicals are
believed to have the potential to contaminate groundwater.

“We have discussed this with Cuadrilla and agreed that a pause in
operations is appropriate so that a better understanding can be gained
of the cause of the seismic events,” the British Department of Energy and Climate Change said in a statement.

Experts from the British Geological Survey, the government and Keele University are examining the data, “and we will need to consider the findings into the cause of the event,” the department said.

The halt was called after the British Geological Survey recorded an earthquake early on May 27 at a depth of about 1.25 miles, with a magnitude of 1.5.

“Any process that injects pressurized water into rocks at depth will
cause the rock to fracture and possibly produce earthquakes,” the survey
said on its Web site.

Brian Baptie, the top seismology official for the organization, said in a
statement that measuring instruments had been installed close to the
drill site after a magnitude 2.3 earthquake occurred on April 1.

“The recorded waveforms are very similar to those from the magnitude 2.3
event,” Mr. Baptie said, “which suggests that the two events share a
similar location and mechanism.”

The two quakes were barely perceptible to humans.

Industry officials say Europe is a decade or more behind the United
States in its effort to recover “unconventional” hydrocarbons like the
oil and gas in shale. Governments and energy companies have viewed
technologies like fracking as a means to reduce European Union
dependence on imported oil and gas, but there can be no certainty that
exploitable deposits exist without further testing.

Cuadrilla’s announcement came as the French Senate on Wednesday began a debate on a proposed fracking ban.

The lower house of Parliament on May 11 passed its own bill,
which would prohibit fracking in the exploration and recovery of oil
and gas, and would revoke existing exploration contracts that relied on
the procedure. The Senate, though, is considering a measure that would
leave open the door to fracking for research.

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