The OGA is aware of a number of minor seismic events recorded in the Preston New Road area, including one of magnitude 0.76 yesterday and another of magnitude 0.78 that happened today shortly after injection operations had completed. Both are at an approximate depth of 2 km.

Hydraulic fracturing is known to cause minor seismic events of this magnitude. While the operations at the Preston New Road site have been designed to minimise any disturbance, minor events like these were expected.  The OGA’s traffic light system and the operator’s Hydraulic Fracture Plan (HFP) require a pause in operations following even these minor seismic events, to allow time for the OGA and the Operator to confirm if the event is in line with the HFP.

The OGA is continuously monitoring operations to ensure they remain in accordance with the operator’s HFP, this includes:

  • Suspension of pumping/injection activities for 18 hours
  • Reducing well pressure
  • Continue monitoring seismicity during the pause in injection operations

Provided that the event is in line with the agreed HFP and the risk of induced seismicity continues to be appropriately managed, then operations may resume on Monday. For more information on HFPs and the OGA’s traffic light system for monitoring operations, click here