Cuadrilla Resources, the British company exploring natural shale gas in the Bowland Basin in Lancashire, has today released the findings of a report that was commissioned following unusual seismic activity near Poulton-le-Fylde in April and May 2011. Cuadrilla´s press release summarizes the report´s main conclusions:

• It is highly probable that the hydraulic fracturing of Cuadrilla’s Preese Hall-1 well did trigger a number of minor seismic events.
• None of the events recorded, including one in April of 2.3 and one in May of 1.5 on the Richter scale, had any structural impact on the surface above.
• The seismic events were due to an unusual combination of geology at the well site coupled with the pressure exerted by water injection as part of operations.
  This combination of geological factors was extremely rare and would be unlikely to occur together again at future well sites.
• If these factors were to combine again in the future local geology limits seismic events to around magnitude 3 on the Richter scale as a “worst-case scenario”.

Cuadrilla’s water injection operations take place very far below the earth’s surface. This significantly reduces the likelihood of a seismic event of less than 3 on the Richter scale having any impact whatsoever on the surface.

Download the full report. See Cuadrilla´s Press release (from 2/11/2011).