For most people, the topic of hydraulic fracturing (fracking) most likely induces one of two very different responses. If you are in the oil and gas business you will probably be thinking enhanced production, unconventional resources and/or microseismic monitoring. If you are not in the business and you have been reading the papers lately then you will be thinking about excessive water use, induced earthquake activity and groundwater contamination
Once again I am writing this article well in advance of the publication date of November but there are three items I would like to draw your attention to. The first is our own Microseismic Users Group (MUG). MUG has monthly meetings and the September meeting featured Dan Walker, who presented, “Frac Induced Seismicity in the Horn River Basin”.
Directly related to his talk is a document that was recently published by the British Columbia government (http://www.bcogc.ca/document.aspx?documentID=1270). The B.C. Oil and Gas Commission launched its probe after a “number of anomalous, low-level seismic events” were detected in the Horn River Basin, the gas-rich shale formation that’s attracted some of the industry’s biggest players.
The agency said, “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 preexisting faults”.
Separate studies have also linked fracking to earthquakes around shale formations in England and Oklahoma.
The 38 events detected by Natural Resources Canada ranged between magnitudes of 2.2 and 3.8 on the Richter scale. A quake of between 4.0 and 4.9 is considered “light” and may cause a noticeable shaking of indoor items and rattling noises.
Only one of the quakes was felt at the surface by “workers in the bush” on May 19, 2011 and there have been no reports of injury or property damage.
Most evidence suggests that it is the sustained injection over periods of months and years that will induce seismicity. For example, the continuous injection of fluids at the Rocky Mountain Arsenal in Colorado is blamed for reactivating the long dormant Golden Fault.
The report stated that, “In undertaking the investigation, the commission notes that more than 8,000 high-volume hydraulic fracturing completions have been performed in northeast British Columbia with no associated anomalous seismicity”.
The report said no quakes were recorded in the area prior to April 2009. It said all of the events began after fracking took place. The quakes happened within five kilometres of fracking operations and within 300 metres of the depth at which the rock was being fractured.
Among other things, the report recommends improvements in seismic detection in the area, further study to identify preexisting fault lines and stronger monitoring and reporting procedures.
It also calls for an examination of the relationship between hydraulic fracturing parameters and seismic activity. For instance, lower pump rates or injection volumes may be considered.
The report stated that, “It is essential to take pre-emptive steps to ensure future events are detected and the regulatory framework adequately provides for the monitoring, reporting and mitigation of all seismicity related to hydraulic fracturing, thereby ensuring the continued safe and environmentally responsible development of shale gas within British Columbia”.
The Canadian Association of Petroleum Producers welcomed the report’s recommendations, acknowledging that seismic activity associated with oil and gas extraction is of concern to the public.
Dave Collyer, president of the energy industry group, said natural gas companies provided the commission with data for its study and support its conclusions. The industry is finalizing guidelines for operators and is financially supporting more seismic monitoring in the region.
“Continuing our record of no harm to people or structures is paramount, as is supporting geoscience that can assure landowners and the public hydraulic fracturing can and will continue safely.”
As an industry we have the greatest ability to monitor the side effects of fracking. We can monitor fracs in a downhole environment, on the surface and with time. Clearly this is an opportunity for our industry to properly monitor this induced seismic activity and proceed accordingly.
The third item is the 2012 Gussow Conference in Banff Nov. 6-8. The theme of the conference is very topical given recent efforts by governments and regulators to address the fracking issue. The aspiration of this theme is to bring clarity to the scientific aspects of hydraulic fracturing within the context of the energy requirements of society. Also, discussions on the tangible environmental impacts of this industry activity will be addressed. The talks will focus on the most current information on the process based on observation and therefore the program will strive to be multidisciplinary with a strong science-based approach. The goal of the conference precludes providing an opinion or proposals regarding fracking, rather to provide factual information on both the process and impacts of hydraulic stimulation as a common ground to address industry standards, societal needs and environmental concerns.