Hydraulic fracturing at Preston New Road: update
Hydraulic fracturing operations at the Preston New Road site are currently paused following a minor seismic event.
A number of minor seismic events were recorded in the Preston New Road area, including one of magnitude 1.5 at 11:21 today (11 December). As this event exceeded the magnitude 0.5 limit set for caution in the “traffic light system”, the operator has suspended pumping/injection activities for a minimum of 18 hours, reduced well pressure and is continuing to monitor seismicity during this pause.
During pauses, the OGA compares the location, magnitude and ground motion of these minor seismic events to the operator’s approved Hydraulic Fracture Plan (HFP).
OGA 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 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.”
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.
- University of Liverpool’s report "Seismic Context Measurements for Induced Seismicity" can be found here.
- To date, five seismic events at Preston New Road have exceeded the magnitude 0.5ML limit for caution.