Fracking for Oil & Gas Leads to Damaging Earthquakes — Part 2

Change Canadian Fracking or Expect More Damaging Earthquakes

From an Article by Andrew Nikiforuk, The Tyee News Service, May 26, 2021

This new warning comes from a former senior scientist with the BC province’s oil and gas commission, Allan Chapman.

Effects of repeated injects build up: study

Cumulative injection has played a dramatic role in triggering many tremors in the Montney region, said Allan Chapman.

In November 2018, for example, CNRL set off three tremors by injecting nearly 15,000 cubic metres of water in two hydraulically fracked wells that resulted in three quakes, including a magnitude 4.6 tremor that rattled the Site C dam and shut down construction operations for a day. “However, this seems to be the proverbial straw that broke the camel’s back,” noted Chapman in his recent report.

Prior to the three headline-making tremors, four operators within a five kilometre radius of the seismic events had injected 1.72 million cubic metres of water into 109 fracked wells over a period of three years. “As many as 29 per cent of the Montney earthquakes are associated with hydraulic fracturing conducted by multiple operators over antecedent time periods of one year and longer, in some cases as many as four operators,” noted the report.

Various studies by both U.S. and Canadian researchers have demonstrated that stresses from frack operations can migrate distances of over 10 kilometres through natural fractures in the rock and destabilize rock pressure for long periods of time, making it impossible for industry or regulators to predict when earthquakes might occur from fracking.

Research commissioned by the BC Oil and Gas Commission acknowledges that “only small fluid pressure increases are sufficient to cause specific sets of fractures and faults to become critically stressed,” in the southern Montney.

“Once you have primed an area and started the triggering of earthquakes, it doesn’t take much more injection to keep the seismicity going,” said Gail Atkinson, one of Canada’s top seismic hazard researchers.The scientist described Chapman’s study as “excellent work” and an important contribution to the research.

Atkinson, who held an Industrial Research Chair in Induced Seismicity at Ontario’s Western University until her retirement in 2020, added that Chapman’s findings are consistent with what she’s found in her own studies on fracking and earthquakes in Western Canada’s oil and gas fields. “Some areas, once you get them going seismically are much harder to turn off than on.”

Drilling by Petronas in 2015 provides an example of the importance of cumulative impacts in Chapman’s study. In August of that year, the company’s fracking generated a magnitude 4.6 earthquake in the north Montney. “For this event, Petronas was the sole operator, injecting 67,625 cubic metres of frack fluid into three wells in the week before the earthquake,” noted the science paper. But over a two-year period prior to the event, Petronas had injected a total of 275,000 cubic metres of frack fluid into the ground.

‘Traffic light protocol’ won’t brake a big quake: experts

In 2015, the BC Oil and Gas Commission introduced the traffic light protocol in an attempt to control damaging earthquakes. According to the protocol, if a company causes an earthquake of magnitude 4 or greater within three kilometres of its fracked well, it must shut down its operations — a red light event.

The protocol in the southern Montney uses magnitude 3 as its red light for stopping fracking. (In contrast, the United Kingdom set magnitude 0.5 as its red light.)

Many researchers including Atkinson have questioned the efficacy of the protocol, because many induced earthquakes don’t produce smaller “yellow light” warning events. Fracking can also cause large earthquakes months or even years after a well has been fracked. And local ground-shaking motions can be severe at much smaller magnitudes.

Many magnitude 3 earthquakes in B.C. have been triggered by wells nearly six kilometres from the epicentre. “Only 26 per cent of the trigger wells are within three kilometres of the earthquake,” reported Chapman. However, some of the larger observed triggering distances may be a result of significant uncertainty in earthquake locations.

B.C.’s traffic light protocol has been inconsistently enforced and is “ineffective,” Chapman said.

Calls for ‘no-frack zones’ near key infrastructure

Chapman calls for a more stringent traffic light system and legislation that requires companies to make their own seismic monitoring public as a condition of operation. Currently, much seismic information in the oil patch is considered proprietary and may not be made public for a year after a quake.

He’s also advocating for an enhanced earth monitoring system that collects more real-time data with a much larger network of seismographs than currently exists. “Let’s say we get a 5.5 magnitude quake and there are deaths and damages and the Peace River Bridge is underwater,” said Chapman in an interview. “And four companies are found to be fracking in the same area at the same time. Having clear and transparent information on these events will help with accountability.”

These changes need to be made now, because the completion of the Coastal GasLink pipeline and LNG Canada by 2025 will drive increased activity in the region with an additional 10,000 fracked wells. That means injecting into underground seams 230 million cubic metres of water, enough to fill 100,000 Olympic-sized swimming pools. Which would be almost six times more frack fluid than was injected during the 2012 to 2019 period of fracking the Montney basin.

Chapman has little doubt that will destabilize parts of the Montney resulting in more or larger earthquakes. “The implications are quite profound,” he said.

The hydrologist also thinks that First Nations, community groups and engineers of bridges and dams in the region need to be engaged in transparent public discussions about the growing earthquake risks posed by fracking. “Other agencies like ministries of highways and transportation need to be involved and engaged because bridges once thought to be risk-free are no longer risk-free with fracking.”

Atkinson supports Chapman’s call for no-frack zones near critical infrastructure, calling the idea a “no-brainer.”

Given science’s inability to predict large induced quakes, “the best approach — the only one shown to work — is basically have a no-go zone around critical infrastructure. It is a puzzle to me why it is such a hard sell given the abundance of oil and gas resources in the region.”

Alberta researchers and Ryan Schultz at Stanford University have questioned whether B.C. and Alberta are doing enough to monitor and prohibit fracking tied to tremors. Traffic light protocols, as currently designed, wrote Schultz, increase “the chances that runaway earthquakes could cause unacceptable damage.”

###