W.Va. Provisionally Ready for Injection-Induced Earthquakes
The State Journal
4 January 2012
By Pam Kasey
A debate over the link between earthquakes and wastewater injected
underground resurfaced over the holidays as dual Christmas Eve and
New Year's Eve quakes capped off an extraordinary 11 tremors for
the year near an injection well in northeast Ohio.
The Ohio Department of Natural Resources suspended activity at an
active injection well at the center of the seismic activity
northwest of Youngstown as well as at four nearby inactive wells,
pending an investigation into a possible connection to the quakes.
At magnitudes ranging from 2.1 to 2.7, most of the tremors were
too small to cause damage. Only the last, at 4.0, was strong
enough to cause structural damage.
So how important is it for a state to respond to such a situation?
"We know from earlier studies, not necessarily in this area but
out west, that man has produced earthquakes that are over 5.0
because of fluid injection," said Marshall University geologist
Ronald Martino. "You're getting into a range where homes,
highways, bridges, even dams can be damaged."
Is West Virginia ready for a similar situation?
Geologists: Injection Can Cause Quakes
Underground injection wells have been used for many decades to
dispose of waste fluids. In Ohio, as in West Virginia, they are
regulated by the state.
Injection wells have been connected with seismic activity in
several isolated instances in the past: near Denver in the 1960s,
in some other western states and, around the turn of the century,
near Ashtabula in northeast Ohio.
The use of injection wells has intensified in some locations over
the past decade with the growing need to dispose of hydraulic
fracturing flowback from horizontally drilled natural gas wells.
A series of hundreds of tremors in central Arkansas in 2010-11,
culminating in a 4.7-magnitude quake in February 2011, led the
Arkansas Oil and Gas Commission to close a fracturing fluid
disposal well and to ban new wells in a 1,000-square mile radius.
Youngstown doesn't usually have earthquakes. The 11 quakes there
dominated the list of 18 quakes over 2.0 originating in Ohio in
2011, according to the Ohio Seismic Network's database, while none
of the 70 earthquakes listed for 2000-2010 occurred near
Youngstown.
"Injection-induced seismicity, there's no question about that,"
said West Virginia University geologist Tom Wilson, a view
affirmed by all of the geologists The State Journal contacted.
"Swarms" of earthquakes like the Youngstown incident can happen
naturally, according to WVGES Director Michael Hohn.
But the contextual factors — the history of seismicity, the
history of injection, the timeline, the depths — would help
determine the likelihood of causation, Hohn said.
After Ohio DNR suspended activity at the wells near Youngstown,
the Ohio Oil and Gas Association issued a statement Jan. 1
supporting the suspension for the "safety and peace of mind" for
residents.
"We believe the situation in Youngstown is a rare and isolated
event that should not cast doubt about the effectiveness or usage
of … injection wells, which have been used safely and reliably as
a disposal method for wastewater from oil and gas operations in
the U.S. since the 1930s," said OOGA executive vice president
Thomas Stewart in a media release.
One Ohio lawmaker said the response was not enough.
State Rep. Robert Hagan, D-Youngstown, told the Youngstown
Vindicator that the state did not act quickly enough for public
safety, and that he would renew his call for hearings on a bill he
co-sponsored for a moratorium on injection wells.
W.Va.'s Approach
The West Virginia Department of Environmental Protection
establishes a pressure permit limit for each injection well using
an Environmental Protection Agency–approved method, according to
DEP spokeswoman Kathy Cosco.
West Virginia has no formal plan for dealing with a situation
similar to Ohio's, Cosco said.
However, it would first pursue a response that succeeded in 2010
following a series of eight quakes in Braxton County near a
Chesapeake Appalachia
injection well, she said.
In that instance, Chesapeake had been permitted to inject at a
pressure of 2,100 pounds per square inch, she said, and agreed to
cut back. As the quakes subsided, the company, in cooperation with
DEP, gradually ramped back up to the permitted injection pressure,
without negative result.
"Do we know whether that was a direct correlation? We don't,"
Cosco said.
Better Instrumentation?
If an earthquake swarm were to start again near a West Virginia
injection well, Hohn said, the well operator might have and be
willing to share proprietary subsurface "ultrasound" data to help
understand what's going on.
Also, "you could surround the area with instruments that could
measure more accurately the location and depth," he said. "That
will tell you if there's a single location and how close to the
injection it is. We've looked into doing that for our state if
something like this occurs."
Martino would like to see more permanent instrumentation.
"You need at least three to four stations surrounding the area,"
he said.
"Clarksburg, Sutton, Charleston, maybe Parkersburg, would be
helpful. We could use better data, and that's something the state
or federal government could do with a few tens of thousands of
dollars."
Short of that, the Braxton County approach was an appropriate
response, according to WVU geologist Tim Carr.
"It happens, and it's manageable," Carr said. "You either shut the
well down or you reduce the injection rate."
It may indeed come up again in West Virginia.
The western part of the state has a larger number of deeper faults
that may make it susceptible to this kind of activity, according
to Wilson.
And Carr pointed out that, because Pennsylvania has a very low
number of injection wells, those just outside its borders — that
would include the Youngstown-area wells and, of the 13 commercial
injection wells on West Virginia DEP's database, a couple in
Monongalia County — draw business from a large area.