Facts on Seismicity
MYTH V. FACT ON SEISMIC ACTIVITY IN OKLAHOMA
MYTH: Hydraulic fracturing is causing most of the earthquakes in Oklahoma.
FACT: As noted at www.earthquakes.ok.gov, the focus of recent heightened seismic activity in Oklahoma has been surrounding the use of disposal wells, NOT hydraulic fracturing. The state has taken rigorous action, in collaboration with the scientific community and with cooperation from industry, to cap disposal volumes. Since June 2015, the frequency of seismic events has rapidly declined by more than two-thirds according to data from the Oklahoma Geological Survey.
When it comes to hydraulic fracturing, the state announced in December 2016 new seismicity guidelines to address anomalous seismic activity that has occurred near completion operations. In the announcement, the Oklahoma Geological Survey (OGS) Director Dr. Jeremy Boak said, “Unlike the strong earthquake activity in areas of the AOI linked to disposal activity, response to seismic activity that might be related to hydraulic fracturing can be more precisely defined and rapidly implemented.” Dr. Boak has called these quakes “small and manageable,” and said there have been few – if any – confirmed above a magnitude 3.0.
The U.S. Geological Survey (USGS) says that “fracking causes extremely small earthquakes, but they are almost always too small to be a safety concern.” Some in the scientific community have called these “microearthquakes,” indicating that they are too small to be felt and have not been linked to inducing large, destructive earthquakes.
MYTH: The oil and natural gas industry has been uncooperative with helping to address seismicity.
FACT: The oil and natural gas industry in Oklahoma has been and continues to take active steps to provide transparent and real-time data with researchers as well as state regulators. This data is made possible by new, innovative technology that large, active drillers, many of which are members of OKOGA, are investing in and using to self-regulate and to better understand induced seismicity.
Industry has also provided researchers and regulators millions of dollars of proprietary research to update fault maps. The oil and gas industry also supported state legislation that passed in 2016 and supported regulatory changes that further strengthen the Commission’s authority to take action on events that have potentially critical environmental or public safety impact.
It’s equally important to note the FracFocus program in which industry fully discloses to the public the location of all its hydraulic fracturing operations and the chemicals being used. Industry is committed to continued transparency.
MYTH: Hydraulic fracturing and wastewater disposal wells are one in the same when it comes to seismicity.
FACT: Hydraulic fracturing and disposal wells are two separate processes that are governed by different regulations because their purposes are quite different.
Disposal Wells: As defined by the U.S. EPA, companies use disposal wells to place produced water into deep geologic formations as a means of preventing groundwater contamination. The federal standards regulating disposal wells are codified under the Safe Drinking Water Act and the method continues to be viewed by the U.S. EPA as the safest method of dealing with produced water.
Although the general public is most familiar with disposal activities related to oil and gas, disposal wells are also used by a number of industries to store carbon dioxide and dispose of hazardous industrial byproducts.
As OCC and OGS continue to research the state’s recent seismic activity, OKOGA has been on the record saying that our members have supported and will continue to support OCC’s efforts when based on sound science.
Hydraulic Fracturing: According to the U.S. EPA, hydraulic fracturing is a technical process to produce fractures in the rock formation that stimulate the flow of natural gas or oil, increasing the volumes that can be recovered. Fractures are created by pumping fluids at high pressure down a wellbore and into the target rock formation containing oil or natural gas. Some of this fluid returns to the surface – known as “flowback” – within the first few days during and after fracking occurs, although much of it remains in the target formation.
Flowback is often treated and can even be reused in additional completion operations. The formation also typically contains saltwater, or brine, which is produced alongside the oil and natural gas. This is what’s known as “produced water,” which industry is seeing minuscule amounts of in the SCOOP and STACK plays (learn more here).
Click here to view a video of a hydraulic fracturing process.
MYTH: Companies only use disposal wells in Oklahoma to get rid of wastewater from fracking.
FACT: Disposal wells are used primarily to dispose of oilfield brine, which is produced from all oil and gas wells, whether fracking was used or not or whether from horizontal or vertical wells.
As noted on www.earthquakes.ok.gov:
In many locations, wastewater has little or nothing to do with hydraulic fracturing. In Oklahoma, less than 10% of the water injected into wastewater disposal wells is used hydraulic fracturing fluid. Most of the wastewater in Oklahoma is saltwater that comes up along with oil during the extraction process.
Although the general public is most familiar with disposal activities related to oil and gas, disposal wells are also used by a number of industries to store carbon dioxide and dispose of hazardous industrial byproducts to prevent groundwater contamination.
MYTH: Earthquakes continue to be on the rise in Oklahoma, with the state registering three historic events in 2016.
FACT: Since June 2015, the frequency of seismic events in Oklahoma has rapidly declined by more than two-thirds according to data from the Oklahoma Geological Survey. Dr. Jeremy Boak of OGS has said that by controlling the frequency of seismic events, it lowers the probability for larger events, and calls the reduction in frequency overall good news for Oklahoma.
This downward trend was most recently highlighted by the Oklahoman when it reported that fewer 3.0 and higher magnitude earthquakes took place in Oklahoma in January than the previous time period last year. The paper reported that, “Within the last 30 days, only 18 quakes with a magnitude of 3.0 or higher were recorded. In January 2016, 102 earthquakes with a 3.0 or higher magnitude were recorded.”
As geological research advances, so too do the opportunities to reduce seismic activity. As reported in Science Daily on Nov. 11, 2016, Stanford geophysicists have compiled the most detailed maps yet of the geologic forces controlling the locations, types and magnitudes of earthquakes in Texas and Oklahoma. These new maps of the geologic forces contributing to earthquakes in Texas and Oklahoma “could help reduce the likelihood of human-made temblors.”
The Oklahoma Energy Resource Board released the following educational video to review what the state of Oklahoma has learned to date about seismicity:
Last updated: Wed., February 15, 2017