Cuadrilla Pauses Fracking After Tremor
UK shale gas explorer Cuadrilla has triggered the biggest tremor since it resumed fracking in mid-October. British Geological Survey recorded that a 1.5 magnitude tremor occurred at December 11 at 11.21am, preceded by ten micro-tremors (none greater than 0.1 magnitude) on December 10-11 all in the Blackpool, northwest England area. It noted that the largest tremor was “felt in Blackpool.”
This is the largest tremor since Cuadrilla’s first fracking nearby in 2011, which triggered tremors of 1.5 and 2.3 magnitudes and which put a seven-year break in the company's attempt to produce gas from the prolific Bowland shale play. The most powerful tremor at Cuadrilla's site of 2018 was a 1.1 magnitude one on October 29 following fracking.
Cuadrilla said: “A series of micro seismic events in Blackpool have been recorded on the British Geological Survey website this morning following hydraulic fracturing at our shale gas exploration site in Preston New Road, Lancashire. “The largest recorded was 1.5ML (local magnitude) at about 11.20am. This occurred after hydraulic fracturing had finished for the day.” It added: “Cuadrilla will pause and continue to monitor micro seismicity for at least the next 18 hours, in line with the traffic light system regulations. Well integrity has been checked and verified."
UK upstream regulator the Oil and Gas Authority's director of regulation Tom Wheeler, said: “Our regulatory regime is deliberately cautious with strict controls in place to manage and monitor seismicity. This pause in operations allows us to review the event to ensure it is in line with the geological understanding set out in the Hydraulic Fracture Plan (HFP) and that the risk of induced seismicity is being appropriately managed by the operator. This is the largest seismic event triggered by the Preston New Road operations to date and it may have been felt by some people close to the site. The vibrations of an event like this are similar to the vibrations caused by a lorry or a coach passing on a nearby road. The event would have needed to be more than 30 times greater for there to be even the possibility of superficial damage to property.”
The 1.5M event on December 11 was the 47th tremor near the Cuadrilla site since the company began its 2018 fracking programme October 15 – the first having been on October 18 – although most have been very minor.
Most recent UK earthquakes up to Dec.11 - for full list going prior to Nov.22 use this link (Credit: British Geological Survey)
Graphic below shows the UK 'traffic light' system, which obliges shale explorers to pause fracking if a 0.5M or greater quake occurs (Credit: OGA)
