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Fallout from fracking Debate rumbles on over links between hydraulic fracturing and earthquakes Gary Park for Petroleum News
Just as the pace of exploration is accelerating in British Columbia’s Montney region, which holds the key to success in Canadian LNG exports, the use of hydraulic fracturing to open up the gas formation has stirred a fresh round of debate.
A new study, by Alan Chapman, an independent researcher and formerly senior scientist with the B.C. Oil and Gas Commission, suggests more damaging earthquakes are likely to be triggered by fracking activities, based on a “fairly strong relationship between the cumulative underground water loading” which is tied to the injection of high-pressure fluids to fracture rocks and release oil and gas.
Chapman said his research suggests homes and infrastructure could be at risk from earthquakes triggered by fracking activities, partly stemming from inadequate safeguards.
Fracking has increasingly been associated with 436 earthquakes up to a magnitude of 4.6 in the Montney region over the 2013-19 period.
Earlier research has linked the pressure under which fluids are injected to earth movement.
Chapman’s studies examined the total water volumes injected into wells within three miles of an earthquake epicenter and included the water build ups - sometimes from several different companies - with quake magnitudes of at least 3.0 which are sufficient to be felt on the surface.
One section of the Montney generated about 20 earthquakes when 1 million cubic meters of fluids were pumped underground and registered more than 160 events when injection grew to 3.5 million cubic meters.
Chapman, noting that many Montney sites have only four wells that could reach 30 wells as development moves to a peak.
Commission critical The B.C. Oil and Gas Commission was critical of Chapman’s peer-reviewed work which the agency’s geological and engineering experts concluded was based on a “number of unproven assumptions or incomplete consideration of the factors cited.”
The commission said the study failed to account for variation of rock strata, fault types and local stresses, calling the conclusions “speculation.”
Regulations in British Columbia and Alberta are managing risk by requiring companies to reduce pumping pressure and volumes once light earthquakes are felt, but Chapman said four of the five biggest recent earthquakes in the Montney were not preceded by any warnings.
Researchers at the University of Calgary have concluded that fracturing fluids can cause slow slips on a fault line, leading to a sudden slip where conditions are unstable, triggering an earthquake.
That finding invalidated claims that earthquakes should not be possible given the type of rock stimulated by fracking.
In February 2020, the Fraser Institute, a public policy Canadian think-tank, challenged the risk claims.
“Seismic activity - which is typically very minor, causing no damage - related to fracking is not due to the practice per se, but rather to wastewater disposal methods which pumps water back into the ground. Research suggests that altering the depth and flow rate of the water injection can minimize the risk of seismic activity,” the Fraser Institute said.
It also said there is no evidence that methane emissions from fracking are greater than what is emitted from conventional wells and that by making natural gas more abundant the process is cutting down on the amount of coal burned in electric power plants.
From beginnings in the early 1950s which went largely unobserved and unreported, the use of hydraulic fracturing in Canada is now a key contributor to oil and natural gas production in the four western provinces.
Changes in fracking A report by the Petroleum Services Association of Canada, said “the science and technology of fracking have evolved over the past 60 years, becoming more productive, sophisticated and safer,” turning into a “game changer” for the industry.
“Advances in the implementation of fracking have come from the collaboration among governments, industry, academics and others to share practices and learning gained from experience and research.”
PSAC said the learning gained from experience and research has contributed to big advances, covering: public disclosure of frac fluids and access to data on the industry’s use of water; more opportunity for public and Indigenous consultation and engagement; and the use of clean technology to reduce the use of water and energy, while generating less waste and decrease the environmental footprint.
Against this backdrop, the industry players doubt there will be any hasty moves by regulators or governments to ban the use of fracking.
- GARY PARK
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