Abstract

We have examined the experiences and learnings acquired through the implementation of the Alberta Energy Regulator’s (AER) subsurface order no. 2 (sub or no. 2) traffic light protocol (TLP). On 22 January 2015, a 4.4 ML seismic event occurred near a hydraulic fracturing operation in west-central Alberta and was felt by residents of the town of Fox Creek. On 19 February 2015, the AER issued sub or no. 2 to help manage induced seismicity, as related to hydraulic fracturing of the Duvernay zone in a prescribed area around Fox Creek. Sub or no. 2 requires operators affected by the order to conduct a seismic hazard assessment; prepare a monitoring, mitigation, and response plan; conduct seismic monitoring; and adhere to a TLP. Since sub or no. 2 was issued, two “red light” events (i.e., ML4.0) have occurred in the area. Review and analysis of data and information collected under sub or no. 2 facilitate an improved understanding of the key geologic and operational controls on induced seismicity and allow for an assessment of the efficacy of industry practices and regulatory requirements. We still support the use of local magnitude ML for our TLP based on the purpose and outcomes provided by sub or no. 2. Conversations with operators have suggested that Shmax orientation should inform the wells’ trajectory with respect to critically stressed faults. The requirement of a response plan was part of the learning process developed under sub or no. 2. Through this exercise, the AER has developed a better understanding of the goals of the response plans, which were better defined through conversations with operators. Sub or no. 2 is consistent with the current state of the evolving science of induced seismicity and has the capacity to change as new information is obtained.

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