Written by Chloe Marie – Research Fellow
In this article, we will provide an update on induced seismicity regulatory developments in the United States. Our last article relating to this topic addressed induced seismicity in Pennsylvania back in May 2016.
On March 1, 2017, the U.S. Geological Surveys (USGS) released its 2017 One-Year Seismic-Hazard Forecast for the Central and Eastern United States from Induced and Natural Earthquakes. This annual forecast is part of the USGS National Seismic Hazard Model Project (NSHMP), whose main objectives are to promote earthquake-resilient building construction, help implement insurance coverage for human-induced earthquakes in property insurance policies, and provide information to the regulatory authorities for the purpose of creating a regulatory framework to manage and prevent the risk of induced seismicity.
In this 2017 forecast, the USGS “acknowledge[s] that human-induced earthquakes can cause damage,” notably as a result of deep wastewater disposal, and thus stresses the important of such short-term forecasting model to better assess the seismic hazard in the United States. The USGS identified five areas of focus prone to induced seismic activity in 2016, including Oklahoma-Kansas, the Raton basin at the Colorado/New Mexico border, northern Texas, northern Arkansas, and the New Madrid Seismic Zone (NMSZ) located on the eastern side of the Rocky Mountains.
According to the USGS forecast, the Oklahoma-Kansas, the Raton basin and the NMSZ focus areas reported human-induced and natural earthquakes with intensity higher than M2.7 throughout 2016, with the exception of the areas of northern Texas and northern Arkansas. More precisely, the Oklahoma-Kansas focus area experienced about 2500 ≥2.7 earthquakes split into 162 independent events and 21 ≥4 earthquakes. As for the Raton basin focus area, it experienced 6 ≥2.7 earthquakes divided into 5 independent events and 2 ≥4 earthquakes. Finally, 24 ≥2.7 earthquakes also happened in 2016 in the NMSZ focus area. The USGS indicated that “only Oklahoma recorded earthquakes with ≥4.7, including the ones that occurred in Fairview on February 13, 2016, Pawnee on September 3, 2016, and Cushing on November 7, 2016.
Interestingly, the USGS found that the 2016 seismicity rates in the five focus areas are somewhat lower than the ones in 2015 but draws attention to the fact that there is a “continuing high hazard in the Oklahoma-Kansas, Raton basin, and NMSZ focus areas.” According to the USGS “about 3 million people live with continuing increased potential for damaging shaking from induced seismicity, and the chance of damage in the next year from induced earthquakes is still similar to that of natural earthquakes in high-hazard areas of California.” The USGS declared that seismicity should be “stationary” over the year of 2017.
In addition, the state of Oklahoma also recently implemented new regulatory and monitoring measures in an effort to reduce and better understand the impacts of induced seismicity.
On December 20, 2016, the Oklahoma Corporation Commission (OCC), together with the Oklahoma Geological Survey (OGS), released seismicity guidelines for operators located in the South Central Oklahoma Oil Province (SCOOP) and the Sooner Trend Anadarko Basin Canadian and Kingfisher counties (STACK) to use during well completion activities. OGS Director Jeremy Boak declared that such guidelines are intended to anticipate and prevent induced seismicity in the SCOOP and STACK regions. Indeed, he mentioned that “while the data indicates that seismicity related to the SCOOP and STACK would be far less frequent and much lower in magnitude than the activity we are addressing in the main earthquake region of the state that has been linked to wastewater disposal, we have enough information to develop a plan aimed at reducing the risk of these smaller events as operations commence.”
Later, on February 24, 2017, the OCC also issued a new directive for the Earthquake Area of Interest (AOI) entitled “Looking Ahead, New Earthquake Directive Takes Aim at Future Disposal Rates.” This directive applies to 654 Arbuckle disposal wells in the Area of Interest and is intended to “keep future [disposal] volume increases in check.” Oklahoma Oil and Gas Conservation Division (OGCD) Director Tim Baker declared that “the continued drop in earthquakes, as well as new data and input from the Oklahoma Geological Survey have caused a change in our orientation from focusing on current disposal volumes within the AOI to looking ahead to try and ensure there isn’t a sudden, surprise jump in those disposal volumes.”
Finally, a study report from Oklahoma’s Water for 2060 Produced Water Working Group (PWWG) was released on April 26, 2017, which is part of the implementation of the 2012 Oklahoma Comprehensive Water Plan (OCWP). Governor Mary Fallin commissioned this study report in December 2015 with the purpose of reviewing the management alternatives of produced water disposal from oil and gas operations. The report concludes that “produced water re-use by the oil and gas industry is the most viable cost-effective alternative due to minimal water treatment needs and thus low treatment costs.”
For further information on hydraulic fracturing and induced seismicity, please view a webinar from the Penn State Extension webinar series that was recorded on April 13, 2017. In that webinar, David W. Eaton, PhD, Professor of Geosciences at the University of Calgary, and the NSERC/Chevron Industrial Research Chair in Microseismic System Dynamics provides a presentation on recent studies on the topic.