Much more study needs to be done about relationship between oil and gas activities and earthquakes
Recent Canadian experience may be instructive for American states worried about earthquakes caused by hydraulic fracturing and waste water disposal wells, as reported in a new study from the Geological Survey.
Both Alberta, home of the Canadian oil and gas industry, and its western neighbouring province British Columbia have been tracking seismic events related to drilling and production for some years now. Studies have demonstrated a strong correlation between fracturing and swarms of small earthquakes, usually ranging from 1.8 to 3.4 on the Richter scale.
But a recent 4.4 quake in Alberta caught the attention of the Alberta Geological Survey and the provincial energy regulator. The event happened not far from the small town of Fox Creek in northern Alberta and it was noticeable on the surface, though no buildings were damaged and no injuries were reported.
As a precaution, the Alberta Energy Regulator enacted a new subsurface order for fracturing crews working in the Fox Creek region. Operators are now required to monitor seismic activity and be able to detect a magnitude 2.0 or greater earthquake within five miles of any well. They must also have a plan on-site on how to respond to a seismic event.
The AER now requires operators to follow a “traffic light” process. Seismic activity greater than 2.0 requires the operator to immediately notify the regulator and implement its response plan. The operator must cease fracturing if the quake is greater than 4.0. The Fox Creek earthquake was the first quake suspected of being caused by fracturing to exceed 4.0.
Industry supported the new regulations.
“We welcome this move by the regulator. Companies operating in the Duvernay supported the regulator in their investigation,” said Brad Herald, CAPP vice-president of Western Canada and Natural Gas Markets. “The new seismic monitoring and reporting requirements ensure our industry operates with the highest regard for public safety.”
This example is instructive because of a study released today by the US Geological Survey that shows earthquakes linked to hydraulic fracturing and waste water injections wells in eight states – Alabama, Arkansas, Colorado, Kansas, New Mexico, Ohio, Oklahoma and Texas.
Oklahoma, in particular, has been hit hard in the past four or five years, even registering a magnitude-5.6 in 2011. The Oklahoma Geological Survey says it is certain the quakes are caused by disposals wells.
The question now is what to do?
For starters, let’s not panic. Buildings aren’t crumbling and people aren’t dying just yet.
But a sensible approach going forward can be gleaned from a 2012 report published by the BC Oil and Gas Commission, which found 272 minor seismic events were caused by fracturing between the 2009 and 2011. Scientists included seven recommendations, most of which involved more research, such as geological and seismic assessments to identify pre-existing faulting, studying the relationship between hydraulic fracturing parameters and seismicity, and establishing induced seismicity monitoring and reporting Procedures and Requirements.
In order words, understand the problem better before rushing to conclusions or actions not justified by data.
Texas has already started this process according to Ryan Sitton, commissioner of the Texas Railroad Commission, who says that since November, 2013 certain areas of Texas have experienced elevated levels of seismic activity, and residents are concerned that this may be caused by oil and gas related activities.
“Since that time, the Commission has held hearings in Azle and Austin, hired an in-house seismologist and adopted disposal well rule amendments that are designed to address disposal well operations in areas of historical or potential seismic activity,” said Sitton in a statement.
“I want the public to know that the Commission is constantly monitoring the situation, and will consider any evidence and data that suggests possible causation between oil and gas activities and seismic events, so that we can take appropriate action if necessary.”
That’s a very good start: More research, more data, and smarter regulation if the data suggests action is required – an approach that has already worked well for British Columbia and Alberta.
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