NETL Researchers Find Tiny Earthquakes Help Marcellus Production

Broadband seismometer used for surface seismic monitoring

We hesitated to use the headline that we did, given the way virulent anti-drillers bastardize the issue of fracking and earthquakes. But we used it to make a point. Quick history: The headline-grabbing “fracking causes swarms of earthquakes” in places like Oklahoma is about frack wastewater that is injected in special saltwater injection wells, deep below the surface. There are, literally, hundreds of thousands of such wells across the country. Unfortunately, when such a well is located directly over or very close to an underground fault (large crack), the fluid getting injected acts like grease, allowing rock layers to slip and slide–in some cases causing low level earthquakes–typically earthquakes under 2.0 on the Richter scale (can’t be felt on the surface). Is fracking itself ever the cause? Statistically, no. But it has been documented to happen in a handful of cases–under 10 times in the entire world, out of millions of fracked wells. And again, it only happened because of fracking directly over an underground fault. However, any time you explode charges underground, which is what fracking is, if you have equipment sensitive enough, you can detect it. Is that an “earthquake”? We’d say no. Perhaps it is considered an “earthquake” according to a technical definition, but those extremely low vibrations are brief–typically 30-60 seconds–and they never cause any kind of harm on the surface. In fact, the vibrations can’t be felt at the surface. So our headline referring to “tiny earthquakes” is somewhat tongue-in-cheek, a way to tweak antis. Researchers at the National Energy Technology Laboratory (NETL) have discovered that those vibrations from fracking–what they call “low frequency tremors”–can be measured and used to figure out how to get more production out of Marcellus Shale wells in PA and WV…

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