- Announcement

Hydraulic fracturing at Preston New Road: update

Hydraulic fracturing at Preston New Road: update

A number of minor seismic events have been detected near the Preston New Road site, which have exceeded our magnitude 0.5 traffic light system threshold. The most recent event, with a magnitude of 1.03, happened at 16:23 on 22 August.

Cuadrilla’s operations have now resumed, following a pause required by the traffic light system.  The OGA will continue to monitor Cuadrilla’s operations to ensure they remain in accordance with the agreed Hydraulic Fracture Plan (HFP). Following any further events exceeding the precautionary threshold, Cuadrilla is required to suspend injection activities for a minimum of 18 hours, reduce well pressure and monitor seismicity for any further events

During these pauses, the OGA compares the location, magnitude and ground motion of these minor seismic events against the operator’s agreed HFP. To date the OGA has been satisfied that these events have been in line with the HFP and that the risk of induced seismicity is being appropriately managed. Operations have now resumed.

OGA Director of Regulation, Tom Wheeler, said: “We know that low level seismic events deep underground can occur during fracturing operations.  This is what happened when the first Preston New Road well was fractured last year and, as expected, we are seeing that again here.  Minor seismic events like these happen naturally in the UK several thousand times every year, and are comparable to vibrations caused by other industries like quarrying or construction.

“As with the first well we are taking a cautious approach and have the same strict controls in place so that even this low level seismic activity results in a pause in operations to allow us to review the event and ensure that the operator’s agreed plan is still valid.”


Notes to editors

  • A graphic/image describing the traffic light system can be found here.
  • For more information on HFPs and the OGA’s traffic light system for monitoring operations, click here.
  • A Hydraulic Fracture Plan (HFP) sets out the steps that the operator will take to minimise seismic risks and the ways in which the operator will monitor and control the hydraulic fracturing process. The HFP must be approved independently both by the OGA and by the Environment Agency (EA), with the Health and Safety Executive (HSE) having had the opportunity to comment.
  • The OGA requires detailed geological studies to be undertaken by an operator to assess the risk of seismic activity, and to prevent any hydraulic fracturing operations taking place near identified geological faults. The OGA must also be satisfied that controls are in place to minimise the risk of a seismic event or any disturbance to those living and working nearby.
  • To date, three seismic events have exceeded the magnitude 0.5ML threshold during Preston New Road Well 2 operations.
  • In total six seismic events exceeded the magnitude 0.5ML threshold during Preston New Road well 1Z operations in late 2018.



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