Confirmation that horizontal drilling and hydraulic fracturing (fracking) caused three central Alberta earthquakes since 2014 has resulted in tightened safety controls on industry operations.
In December the Alberta Energy Regulator (AER) adopted a policing regime known as the “mandatory traffic light protocol” for fracking in the Red Deer region between Calgary and Edmonton.
The rules specify industry “must implement seismic monitoring and response procedures to manage the hazard of induced seismicity before, during, and after any hydraulic fracturing activity,” said the AER.
The regulatory signal light stays green if the ground stays calm. Magnitude one to three tremors turn the light yellow, must be reported and trigger hazard mitigation. Stronger shaking turns the light red, halting wells until the AER is satisfied with safety measures.
The new central Alberta safety policing also prohibits fracking in the prime shale and tight gas target, the Duvernay formation, within 5 kilometers (3 miles) of the flood control Dickson Dam north of Calgary.
Adoption of the fracking safety regime in central Alberta followed completion of a regional field incident review by the AER’s earth-sciences arm, the Alberta Geological Survey (AGS). The fracking traffic-light policing regime was originally devised in response to earthquakes north of Edmonton.
The AGS review identified fracking as the culprit behind Red Deer region earthquakes of magnitude 2.59 in 2014, 3.13 in 2018 and 4.18 in 2019. Area residents felt the 2018 tremor and complained of damage, but no injuries, after the 2019 shaking.
The AGS continues to work on refining methods of identifying underground conditions that make fracking sites high earthquake risks. Industry is contributing information from tremor detection required by AER regulations.
The scientific detective work is a geological version of finding needles in haystacks. An earth sciences review has found that earthquakes could be blamed on fracking at only 39, or 0.3%, of 12,289 wells where the shale gas technique has been used in the Western Canada Sedimentary Basin.