Thumbnail Image
PADEP Alleges Correlation Between Development and Seismic Event

On February 17, 2017, the Pennsylvania Department of Environmental Protection held a press conference to announce its finding that Utica shale hydraulic fracturing activities conducted on April 25, 2016 correlated to microseismic, or unfelt seismic events. According to PADEP, hydraulic fracturing activities conducted in Lawrence County correlated to seismic events of 1.8-2.3 magnitude on the Richter Scale. Natural seismic activity has occurred since at least the 1700s in the northwest and southeast corners of the Commonwealth. Lawrence County is at the southwest corner of the seismic activity zone in the northwest part of Pennsylvania.

PADEP noted in its press conference that Lawrence County has several contributing factors that makes induced seismicity more likely during the stimulation of the Utica shale, including brittle rock fracture, increase or change in pressure regimes proximal to active faults, fault plane orientation, and minimal separation of basement rock and the area of concern. PADEP stated that during the seismic event, real-time data was provided by the Commonwealth’s seismic monitoring network to PADEP’s oil and gas department. PADEP notified the operator of the proximity of the seismic events, and the operator voluntarily ceased stimulation activities and demobilized from the well pad within hours.

PADEP has recommended that the operator undertake the following actions:

  1. Continued operation of the operator’s own seismic network within the monitoring area.
  2. If a potentially induced seismic event occurs within the monitoring area, the operator must submit the seismic data received from its network electronically via e-mail to PADEP within 10 minutes.
  3. If a potentially induced seismic event occurs within the monitoring area, the operator must call PADEP within one hour of the event.
  4. Upon occurrence of an event:
    1. The operator will safely shut down stimulation operations on the well;
    2. The operator may flow back the well to reduce pressure
    3. The operator may resume operations if it demonstrates that the event was not correlated to development activities; and
    4. The operator may resume operations if it demonstrates that modifications to operations allow for the safe resumption of stimulation activities.
  5. The operator will cease zipper fracturing activities.

PADEP has stated that it will incorporate these conditions into future well permits near areas of concern and may institute the conditions as field rules in some areas of the Commonwealth.