Is the growth of the gas business in WV shaking up more than the economy? A new Concord University geological initiative could help scientists recognize the potential for man-made earthquakes caused by natural gas drilling. But does the drilling leave the ground more susceptible to earthquakes?
According to the West Virginia Geological survey there have been about 20 measurable earthquakes in the state in the past five years, more than half of those were in Braxton County where Chesapeake Energy was disposing fluid via deep well injection.
Chesapeake voluntarily lowered the pressure of its injections in Braxton County at the request of the West Virginia Division of Environmental Protection in 2010, although they denied the wells had anything to do with the earthquakes.
Dr. Joe Allen is a geology professor and the chair of the Division of Science, Math and Health at Concord University. He hopes to understand rock fracturing and earthquakes better by studying West Virginia’s geology from Greenland. A grant from the Higher Education Policy Commission is helping to launch the first steps. His trip this fall is to study fossilized fractures in rock, not to be confused with the process of fracking- which we’ll get to a little later. Allen says research in Greenland can benefit West Virginians and their understanding of local basement rock.
“Southern West Virginia actually is the most seismically active in West Virginia,” Allen says. “So again those are deep, we don’t have a good seismic array to tell the depth or distribution of seismicity here or even what rock types they’re fracturing in and so that’s kinda why we have started this other research.”
Basically, the rocks that Allen needs to look at in order to complete his study are easier to access in Greenland. This same layer of rock is buried under ten-thousand feet of sedimentary in the state, under West Virginia’s coal, oil and gas reserves.
The idea behind Allen’s research is to understand how preexisting patterns in Greenland rock texture, might influence the direction and shape of fractures.
So, it’s kinda like splitting wood. Sometimes wood will split around a knot while at other times it will go through it. Understanding how these cracks form, where they start and stop, how fast they form and how much stress is involved are all part of the study.
A recent study published in Science Magazine called “Injection-Induced Earthquakes”, makes a connection between fracking, waste-water disposal, and human -induced earthquakes.
Fracking is an industry-invented term that refers to the process of injecting water into rock in order to release oil and gas for collection. The process of fracking takes advantage of existing fractures in the rock to reach gas. Some of that injected water will then be pulled back out of the rock creating what’s called “flow-back” or waste water. That water is often then injected into a separate deep well for disposal.
The Science Magazine article reports that the actual process of fracking has a low risk of inducing an earthquake. However, the wastewater disposal or injection into deep wells presents a higher risk for creating stronger, human-induced, earthquakes.
“There’s been a series of earthquakes in the mid-continent of the US in Youngstown, Ohio," Allen said. "There’s some in Oklahoma and there’s been some recent studies that show a correlation between some of those there in the order magnitude of four to five earthquakes but they are directly related to hydraulic fracturing."
"So they were basically man induced earthquakes.”
The Science Magazine article noted that the 2011 Oklahoma quake destroyed 14 homes and injured two people and a fault, weakened by increased fluid pressure, appears to be the cause. Since 2000 the number of midcontinent earthquakes of magnitude three or stronger has increased from an average of 21 per year to a peak of 188 in 2011 and human induced earthquakes are suspected to be partially responsible.
While West Virginia isn't known for generating strong earthquakes, Allen says he believes the potential for damage still exists. For example, a strong earthquake along Pacific fault lines could trigger a local quake since the energy produced from a distant quake travels around the world.
Allen says pre-existing faults already weakened by hydraulic injection, waste water disposal, or gas and oil extraction may be more susceptible to movement.
So far, federal studies and much of the research surrounding fracking has focused on the chemicals used in the process and the possibility of ground water contamination. The article in Science Magazine says that it seems the more water, pressure or use of both, the more likely there will be a man-made earthquake. Allen’s research might help to determine just how vulnerable West Virginia is to man-made earthquakes, because of fractures that already exist deep underground.
Dr. Allen’s grant is one of four recently awarded to Concord University’s Division of Science, Mathematics, and Health. Other professors will use the money to research biomedical chemistry, and enhance classroom experience.
