SAN DIEGO -- Here are the facts: "Fracking" does not cause big earthquakes. The underground injection of industrial wastewater can, and sometimes does.
Bill Ellsworth is frustrated at how difficult it is getting people to understand this.
The senior U.S. Geological Survey geophysicist is on the cutting edge of new research linking earthquakes to the injection of oil and gas drilling waste (EnergyWire, March 29). But at last week's earthquake conference here, he seemed to spend as much time trying to resolve the "fracking" confusion as he did explaining his findings.
Earlier this month, he even found himself arguing with a cable news host about what his own research conclusions were.
"I was greatly surprised to see how words were being used in the press in ways that were inappropriate," Ellsworth said as the annual meeting of the Seismological Society of America wrapped up. "We don't see any connection between fracking and earthquakes of any concern to society."
Ellsworth has stumbled upon a key fault line in the nation's debate about its onshore oil and gas boom.
On one side are oil and gas companies, which use the term "fracking," or "hydraulic fracturing," to describe just one part of the whole production process. Fracturing involves blasting chemical-laced water and sand deep underground to break apart rock and release gas.
Critics, often environmentalists, apply the "fracking" moniker to all aspects of shale drilling -- from the first truck that shows up at the well pad all the way through to waste disposal and plugging.
Because of this divide, the drilling industry's critics and boosters argue a lot, but they often refuse to talk about the same thing.
In the middle are people with a passing interest, like CNBC host Brian Sullivan, who interviewed Ellsworth on April 9 about drilling and earthquakes. He got frustrated when the scientist said fracking did not cause big earthquakes.
"Bill Ellsworth, [I'm] looking at a very reputable site on the Web, not going to say by name because we all make mistakes: 'His executive summary point is geologists have made direct links between fracking and recent earthquakes,'" Sullivan said, challenging Ellsworth's description of his own research with the description of his research by an unnamed news site. "That sounds like you're saying that's a completely incorrect statement."
"It is incorrect," Ellsworth responded. "What we've found is there's a link between disposal of wastewater and earthquakes."
Ellsworth and his fellow USGS researchers brought their evidence of that link to last week's meeting of the country's leading earthquake researchers (EnergyWire, April 19).
He told his fellow seismologists, who are researchers from universities and government agencies, that they have an obligation to set the record straight on fracking, deep wastewater injection and earthquakes.
"As scientists we have an obligation to try to give people the benefit of scientific understanding," Ellsworth said. "The public has legitimate concerns for which it needs good information."
Quakes raise red flags
Ellsworth and University of Oklahoma professor Katie Keranen and others explained the links they found between oil and gas waste injection and two significant earthquakes last year, a magnitude-5.3 one in southern Colorado in August and a magnitude-5.6 quake east of Oklahoma City in November. The Colorado quake caused only minor damage, but the Oklahoma quake injured two people and destroyed 14 homes.
They were part of a 600 percent spike in earthquakes greater than magnitude 3.0 -- roughly the level considered strong enough to be felt at the surface -- during the last 10 years in the middle of the country.
"Something is going on out of the ordinary," Ellsworth said. "The largest preponderance of evidence," he said, points to the Oklahoma and Colorado quakes and the rise in the number of midcontinent earthquakes being caused by injection of wastewater from oil and gas drilling.
Geologists for the states of Oklahoma and Colorado have deemed such conclusions "premature," saying more research and analysis need to be done (EnergyWire, April 16).
But state regulators in Ohio recognized a link between drilling waste injection and a series of earthquakes in Youngstown that culminated in a magnitude-4.0 quake on New Year's Day (EnergyWire, March 9). And Arkansas officials last year implemented a ban on injection in a part of their state that appears to have dissipated a "swarm" of earthquakes there.
In Arkansas, Ohio and many other states, there is a lot more wastewater to inject deep underground because a surge in oil and gas drilling in shale formations has created a lot more wastewater to inject.
Here's where "fracking" comes in. Production from the shale formations is dependent on hydraulic fracturing and in particular a specific method of it that requires blasting millions of gallons of fluid into horizontal wellbores. A lot of that fluid comes back up, even more toxic than it went down. Some can be reused, but eventually most is injected underground.
It has been scientifically established for decades that such injection of industrial wastewater can lubricate faults and unleash earthquakes (Greenwire, Jan. 5). The question is whether injection did cause the recent rash of quakes in the central states.
There's another complicating factor -- hydraulic fracturing itself does appear to have caused some very small earthquakes.
British officials announced last week they would allow Cuadrilla Resources Ltd. to resume fracture treatments despite the company's admission that fracturing caused two small earthquakes near an English village last year (EnergyWire, April 18).
And in San Diego last week, Austin Holland of the Oklahoma Geological Survey described his findings that a series of small earthquakes near Elmore City, Okla., in January 2011 could have possibly been triggered by the fracking of a nearby well (E&ENews PM, Nov. 2, 2011).
But fracking-induced quakes appear to be even less common than injection-triggered quakes, and the earthquakes are much smaller. Holland said the strongest earthquake in the sequence was magnitude 2.9. That is barely strong enough to be felt at the surface. That might be one reason why only one person reported feeling it.
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