From Westlaw Journal Environmental: Chris Faulkner of Breitling Energy, and author of the book “The Fracking Truth,” discusses the connection between the underground disposal of contaminated fracking fluids and earthquakes, and makes recommendations on how to address the ongoing disposal problem.
For a long time, experts believed the act of retrieving oil and gas from shale formations through the method of hydraulic fracturing, more commonly known as fracking, was causing minor earthquakes nearby. The earthquakes were few and far between, and when they did occur, were very minor in nature.
The concern over this, however, and the related media attention, prompted several studies — many of which are still ongoing — by scientists, universities and independent geologists to see if fracking is indeed the cause of the tremors.
While these studies are not all complete, the early results suggest hydraulic fracturing, by itself, does not cause earthquakes.
There is a puzzling caveat, though. After fracking stopped and drillers were disposing their used fracking fluids back into underground injection wells, more earthquakes began to occur, especially in regions where they had rarely, if ever, happened before. So, was it fracking that was causing the tremors, the disposal of spentfluids, or was it just a natural coincidence that this was all happening at the same time?
The most newsworthy events (in terms of media attention, not necessarily severity) took place in major shale oil-producing regions, such as Oklahoma, Arkansas, Kansas, Pennsylvania and Ohio. As a result of these tremors, and the subsequent media coverage, the United States Geological Survey conducted a study that showed the disposal of fracking fluids via underground injection can, indeed, trigger earthquakes. Most of these were minor, below 3.0 on the Richter scale.
Conventional wisdom among geologists is that an earthquake has to be above 4.0 to cause damage other than rattling shelves, anxious pets and, occasionally, shattered nerves.
As an indirect result of the USGS determination, several lawsuits have been filed, including one in Arkansas in February 2014 by two families claiming “swarms and mini-clusters” of quakes in 2010 and 2011 hurt the value of their property. The suit names Chesapeake Operating Inc. and BHP Billiton Petroleum as defendants. The damage from the earthquakes in this particular suit has been negligible and, to date, no injuries have been reported.
Nevertheless, lawsuits continue to be filed not only in Arkansas, but in surrounding states as well. Also continuing is the disposal of contaminated frack fluids via underground injection.
Oklahoma is not only seeing an increase in the number of earthquakes, but also in the number of lawsuits, not necessarily from damage. Though there have been ahandful of cracked foundations and broken household items, most lawsuits surround the potential decrease in property value.
SOONERS BECOME SHAKERS
Seismic activity is not the norm for Oklahoma. Between 1972 and 2008, the USGS recorded a handful of earthquakes each year in the Sooner State. In 2008, there were more than a dozen; four dozen happened in 2009. In 2010, the number ballooned to over 1,000 tremors.
That number continued to swell in 2011 and included the largest quake ever recorded in Oklahoma: a 5.6 magnitude in November near Prague. A subsequent report on the Prague quake discussed the fact that the quake occurred along a “seismically risky” area known as the Wilzetta Fault. They did not rule out groundwater injection as a contributing factor, but they did not place any blame either.
Because these earthquake “swarms” are occurring in places where the ground is not supposed to move, scientists are investigating these irregularities. Many have come to the conclusion that the quakes are indeed linked to the injection of wastewater from fracking operations.
The reason the fracking procedure itself does not commonly produce earthquakes is because of pore pressure, or the measure of how much stress the fluids exert into the“pores” of the rock surrounding the area being fractured. The intention of fracking is to quickly increase the pore pressure just enough to slice fissures into sediment and free the trapped natural gas. This is done so quickly the pore pressure equalizes almos immediately, eliminating any underground stress so there is no effect above ground.
This is the reason no lawsuits have come to court regarding the act of fracking directly causing an earthquake. There are, however, lawsuits in many courts, in many states, regarding earthquakes caused by wastewater injection, and even a few based on the potential for groundwater contamination. Both the USGS and the U.S. Environmental Protection Agency have said they have seen no evidence of groundwater contamination due to fracking.
THE POTENTIAL CULPRIT: WASTEWATER INJECTION
When fracking begins, the fracking fluids are pumped into the well at very high pressures. Ultimately, the fluid returns to the surface.
This is called “flowback.” The flowback, in addition to being mostly liquid, also contains large quantities of natural gas, which is then extracted.
The remaining liquid (wastewater) is pumped into the disposal wells, which are regulated by the EPA and can be up to three miles underground. These disposal wells are encased in layers of concrete and can accommodate millions of gallons of wastewater from many different fracked wells.
Hydraulically fractured wells are designed to tolerate the high pore pressures. Unfortunately, wastewater disposal wells are not. The disposal wells are sometimes created out of permeable rock formations. These areas are very absorbent, and the water that is injected can spread over vast areas underground. Sometimes when the pore pressure rises in these disposal wells, rocks move.
By nature, an earthquake is a movement or shift in a tectonic plate beneath the surface of the earth. The tremors occurring due to injection of frack fluids are not necessarily earthquakes but more small collapses of the ground, much like sinkholes far beneath the surface, which radiate out like a pebble in a small pond.
As of June 2014, none of the larger lawsuits have come to trial, including the Arkansas suit and other suits resulting from the Prague, Okla., quake. Both sides involved in the cases are still trying to gather information to determine several factors, including who is at fault and, therefore, liable to pay for any damages or injuries which may occur as result of these ground shifts.
Before hydraulic fracturing became popular again due to the discovery of large pockets of oil and gas in shale plays, tremors had been noted in many major oil-producing regions that utilized the traditional drilling approach (with the possible exception of Oklahoma). Tremors do occur in non-oil-producing regions, but not as regularly as those where injection wells from fracking have been used.
THEREIN LIES THE PROBLEM
Hydraulic fracturing is, indeed, a double-edged sword. The resurgence of fracking and the development of major shale plays in the regions mentioned above have given the U.S. a chance to be energy independent within the next two decades. There have been oil and gas booms before, but the context of this one is different.Because of hydraulic fracturing, untold amounts of oil and gas are being found and extracted from previously unreachable areas. The result of this is enough oil and gas tokeep the U.S. running for the next two and a half centuries, with supplies abundant enough to export globally. That means more jobs, a trickle-down effect on other industries that service oil and gas, and an enhanced national security, since reliance on foreign oil will no longer be an economic vulnerability.
Energy independence is a noble thought, and one that most Americans look forward to until the dishes come crashing off the kitchen shelves. There lies the dilemma.
HOW DO WE FIX THE PROBLEM?
Fracking is not going away any time soon. The answer may be as simple as finding another way to dispose of wastewater safely and cost-effectively. It may not be easy, but there are several new ideas already being tested, used and studied.
Perhaps the most interesting new development is that some drilling operators have chosen to reuse a portion of the wastewater to supplement fresh water in creating new frack fluids for future wells, or even re-fracturing the same well. Of course, recycling shale gas wastewater is, at least in part, dependent on the levels of pollutants in the wastewater and the nearness of other sites to re-use it.
Transportation costs also come into play, as does the ability to treat the water and safely remove pollutants. The reuse of fracking fluids is a relatively new practice that has the potential to reduce underground injection of wastewater and conserve water resources in the process.
Cliff Frolich, associate director of and senior research scientist at the Institute of Geophysics at the University of Texas at Austin, and an expert on man-made earthquakes, recently presented a few suggestions for mitigating potential seismic tremors.
“We need to find new ways to dispose of drilling-related wastewater,” he said. “If disposal is causing earthquakes, you can find a different way to dispose of it. You can dispose of the stuff in a different well, or you can even take it to a fluid treatment plant.
While both are valid ideas, his first suggestion seems the most plausible. In order for this to happen, disposal wells need to be placed further apart, lessening the chances of unwanted seismic activity. They can be placed in areas that are unpopulated, and will more than likely never be populated.
At a Texas House Committee on Energy Resources hearing in 2012, state officials heard recommendations from several industry experts on what can be done to mitigate the risk of man-made earthquakes. One of the experts to give testimony was Melinda Taylor, director of the center for global energy, international arbitration and environmental law at the University of Texas at Austin. Taylor testified that some states have more safeguards in place against unwanted earthquakes than others.
“In Ohio, well operators must do a fairly detailed analysis of the geological conditions before the state’s regulatory agency issues a permit to authorize a new disposal well,” Taylor said. ”This advance research allows them to determine whether or not it’s likely to cause problems.”
Other states have similar protections, so it is safe to say that the problem is being addressed on many different fronts.
With a common sense, economical and environmentally responsible approach to disposing of, or reusing, fracking wastewater, the U.S. can more successfully continue on the road to energy independence.
Written By: Chris Faulkner, CEO of Breitlng Energy