Drilling down on fracking in Indiana
Editor's note: This story from The Bloomington Herald-Times is being published here as a courtesy for readers of IU in the News.
By Lauren Slavin
Fracking is nothing new in Indiana. Frequent earthquakes would be.
Geologists and environmental activists have been raising concerns for years about increased hydraulic fracturing — called “fracking” for short — and other unconventional oil production methods in the United States. Hydraulic fracturing is the drilling and injection of fluid into the ground to create cracks in rock formations and release natural gas, oil and other energy-producing resources.
Fracking proponents say the practice lessens the U.S. reliance on foreign oil, creates jobs and leads to energy savings in American households. Those who oppose U.S. drilling and using fossil fuels point to accidents at oil wells with detrimental environmental effects, such as a January pipeline leak in North Dakota that spilled 3 million gallons of brine and contaminated two creeks.
And a recently documented natural phenomenon near wastewater injection sites — a byproduct of fracking — has provided environmentalists with another argument against unconventional drilling.
“It turns out that many things that we do that affect the subsurface of the Earth are also capable of triggering earthquakes,” said Michael Hamburger, a professor of geological sciences at Indiana University. “This is one of the unexpected side effects of oil and gas exploration. There are places in Kansas or Texas that have never experienced an earthquake that have now experienced an earthquake and have no idea what to do about them.”
The risk of earthquakes and other seismic activity correlates with wastewater injection, not fracking, though one cannot exist without the other. After a “frack job,” the water and chemical mixtures used to make a well productive must be disposed of in a manner approved by the Environmental Protection Agency. Some of this fluid is cleaned at water treatment plants, but much more is injected back into the Earth.
“The easiest and arguably the safest way to dispose of these is to pump them back into the subsurface in so-called wastewater injection wells,” Hamburger said.
When injected into the ground at high pressures, wastewater acts as a lubricant, reducing the strength of the connections holding faults in the Earth together. Scientists found that fracking in Pennsylvania did not result in increased seismic activity in that state. In neighboring Ohio, however, wastewater injection from Pennsylvania fracking induced more than 100 small earthquakes from 2011 to 2012.
“It’s not that the wastewater injection itself is producing the earthquake. It’s triggering an earthquake that might have happened anyway, and in some cases that could be a very large earthquake,” Hamburger said. “There are tens of thousands of wastewater injection wells in the country, and only a few are producing earthquakes. Unfortunately, we often only know that after they produce earthquakes.”
In an effort to mitigate that risk in Indiana, IU’s department of geological sciences, the Indiana Geological Survey and the state division of oil and gas are working together to create a comprehensive database of all the state’s injection wells and earthquake activity.
“We do have the ingredients for induced seismicity here. We have natural seismic activity; we have pre-existing faults that are under stress; we have injection of wastewater,” Hamburger said. “I don’t have much doubt that as the process continues, there’s increasing potential for this kind of thing here and in our neighboring states, so it’s something we want to be prepared for.”
Indiana is home to more than 77,000 wells, though not all are active. The majority of active wells are located in southwestern Indiana.
“To our knowledge, we haven’t seen any induced seismic activity that could be associated with oil and gas operations, but we want to be prepared,” said Herschel McDivitt, director of the Indiana Division of Oil and Gas. “We want to learn as much as we can about the connection with underground disposal wells and induced seismic activity.”
A typical vertical hydraulic fracturing operation in Indiana results in an average of 10,000 gallons of wastewater, according to McDivitt. Horizontal drilling uses more water, as does hydraulic fracturing in the deepest wells. A vertical well in Gibson County that was once considered unproductive due to its depth was fracked with 300,000 gallons of water.
“Every oil and gas producing state, including Indiana, has limitations on what you can do with that fluid,” McDivitt said. “You can’t just haul it down the road and dump it into a ditch or a stream. We have suitable geology, deep formations that have a lot of capacity to accept fluid and can be done safely and in a manner that’s protective of groundwater and the environment.”
In areas experiencing earthquakes for the first time, damage protections might not be in place for homes and other buildings. An Oklahoma Supreme Court case is currently determining if oil companies are liable for injuries and damages to a woman and her home after an earthquake that seismologists linked to four of the state’s wastewater wells.
In Indiana, the division of oil and gas regulates the oil industry, and earthquake damage is not part of the division’s responsibilities.
“It involves some things that may fall between the cracks in a regulatory system,” Hamburger said.