More injection wells proposed for Pa. sites
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By Kent Jackson (Staff Writer)
Published: January 17, 2012
Pennsylvania has only six injection wells like the one thought to have triggered earthquakes in Youngstown, Ohio, which is why gas companies from Pennsylvania sent drilling liquid to the Youngstown well for disposal.
Citizens respond to speakers during a community forum to discuss recent seismic activity related to deep wastewater injection wells, in Youngstown, Ohio, on Jan. 11. In Ohio, injection wells have been blamed for an increased in seismic activity. Pennsylvania has six such wells with two more proposed for Warren County.
Ohio has more than 175 injection wells. Two more wells are proposed in Pennsylvania’s Warren County, said Kevin Sunday, a spokesman for the state Department of Environmental Protection.
Injection wells are used to store waste deep underground, well below water tables, and generally have a good track record around the nation. Some states, including oil producers Texas and Oklahoma, have hundreds of them. In Pennsylvania, the site of history’s first oil well, injection wells never gained popularity, partly because one malfunctioned. Paper mill waste pumped into an injection well in Erie County in the 1970s returned to the surface.
Now earthquakes are the unintended occurrence at one of Ohio’s wells. Since the well was drilled on Dec. 23, 2010, near Youngstown, 11 earthquakes have occurred in the vicinity. After studying readings from seismic monitors placed near the well in November, Columbia University professor John Armbruster said the most recent earthquake on Dec. 31 occurred at the same depth as the well. Armbruster said the well probably caused that quake, the largest so far, which registered magnitude 4.
Afterward, Ohio Gov. John Kasich halted injection drilling near the well.
In March 2011, Arkansas stopped developing new injection wells in a small area of the state after a series of earthquakes, the largest of which reached magnitude 4.7.
Well operators plugged four wells due to the order, whereas more than 700 wells remain in use in the state, Lawrence Bengal, director of the Arkansas Oil and Gas Commission, said in an email.
Since the moratorium, some seismic activity has continued in Arkansas, but the number and magnitude of the events has decreased, Bengal said.
In Ohio, the earthquakes have not been powerful enough to damage property.
Moreover, nothing indicates that drilling natural gas wells in Pennsylvania has triggered earthquakes.
Gas wells generally are shallower than injection wells and receive lower volumes of liquid. The liquid pumped into gas wells flows back to the surface, whereas it remains underground in injection wells.
In Pennsylvania, companies drilling gas wells seek to reduce the amount of flowback water that they have to put in injection wells or other disposal sites.
Right now, companies recycle more than 70 percent of the fluid flowing back to the surface after drilling and hydraulically fracturing wells for natural gas, said Travis Windle, a spokesman for the Marcellus Shale Coalition.
“Many operators are near a 100 percent recycle rate,” Windle said.
Recycling is better for the environment and for the budgets of gas companies. By reusing water, companies save on disposal costs and reduce the number of trucks hauling water to wells and carting away waste liquid.
The waste contains water that collects salt and from underground sources, plus sand and chemicals used in the fracturing or fracking process.
Even as technology improvements allow gas companies to recycle a higher percentage of the fluid, some fraction of the liquid still remains as waste to discard.
DEP rules forbid gas companies from treating wastewater and disposing it in streams or rivers, which means injection wells will continue to fill a need.
Lack of planning for wastewater disposal and seismic activity at injection wells in Ohio and Arkansas was the first reason that watershed and wilderness groups cited when recommending revisions to New York’s draft statement on the environmental impact of gas drilling.
The U.S. Environmental Protection Agency regulates injection wells, but has no rules against locating wells near faults.
“Other than using common sense when siting these wells, I am not sure that additional regulation would help,” Terry Engelder, professor of geosciences at Penn State University, said in an email.
Engelder said the earthquakes in Youngstown are so small that the faults involved might be invisible to seismic imaging equipment used to examine underground formations.
Before gas companies drill a gas well, Windle said, technicians bounce transmissions of underground rocks to understand the rock’s depth, thickness and potential for holding natural gas.
Fault lines would discourage drillers because earthquakes could damage wells and pipelines.
“It’s not in the company’s interest to produce in a high-risk area near fault lines,” Windle said.
Engelder said fracking a well in the Marcellus Shale touches off thousands of tiny tremors.
“None are felt because they are very, very small,” he said.
Human activity, however, caused more substantial earthquakes, for example, in the 1960s at South African gold mines. The U.S. Army stopped using an injection well at the Rocky Mountain Arsenal in Commerce City, Colo., in 1966 because of worries that the well caused earthquakes.
Drillers seeking to tap sources of geothermal energy also have caused earthquakes in Basel, Switzerland and Landau, Germany, Philadelphia author Reese Palley writes in “The Answer: Why Only Mini Nuclear Power Plants Can Save the World.”
kjackson@standardspeaker.com, 570-455-3636