B.C. commission finds seismic events linked to fracking

The B.C. Oil and Gas Commission has penned several recommendations in response to its finding that anomalous seismicity in isolated areas of northeast British Columbia was the result of hydraulic fracturing.

“The investigation has concluded that the events observed within remote and isolated areas of the Horn River Basin between 2009 and 2011 were caused by fluid injection during hydraulic fracturing in proximity to pre-existing faults,” notes the commission’s report.

Fracking involves injecting water and other fluids at high pressure thousands of metres below the earth’s surface to crack shale rocks and release natural gas. The process has increasingly come under fire because of concerns over the possibility of water contamination and low-magnitude earthquakes, and fuelled discussions over the need for insurance coverage.

The B.C. commission became aware of the anomalous, low-level seismic events, only one of which was ‘felt’ at the earth’s surface, after they were recorded by Natural Resources Canada (NRCan) near areas of oil and gas development. “None of the NRCan-reported events caused any injury, property damage or posed any risk to public safety or the environment,” the commission states.

The report discusses the 38 NRCan-reported events, and 216 and 18 events, respectively, recorded by dense arrays deployed at Etsho and Kiwigana.

The commission’s recommendations include the following:

• submission of microseismic reports;
• establishment of a notification and consultation procedure;
• study of the relationship of hydraulic fracturing parameters on seismicity; and
• upgrading and improving B.C.’s seismograph grid and monitoring procedures.

Grid network upgrades have already begun, the report notes. “The upgraded grid will provide improved monitoring for induced seismicity and will form the basis for the monitoring, detection, notification and consultation procedure.”

Natural gas producers have voiced their support of the recommendations. The Canadian Association of Petroleum Producers is “in the process of finalizing operator guidelines and increasing financial support for more seismic monitoring in the region,” president Dave Collyer says in a statement.