Possible link between fracking and earthquakes
In my book Toxic Capitalism I made a lot of reservations about fracking, causing side-effects such as earthquakes and contamination of water wells. I was wondering how this further evolved, in view of the massive increase in fracking, especially in the USA.
In Alberta, Canada, a direct link between fracking and earthquakes came up. It was researched as explained in detail in the New York Times article dated 17 November by Henry Fountain:
See the full article here: http://www.nytimes.com/2016/11/18/science/fracking-earthquakes-alberta-canada.html
Some excerpts on fracking and earthquakes
In the debate over fracking of oil and gas wells, opponents often cite the risk that the process can set off nearby earthquakes. But scientists say that in the United States, fracking-induced earthquakes are not common.
In Canada, however, a spate of earthquakes in Alberta within the last five years has been attributed to fracking, or hydraulic fracturing, in which water, chemicals and sand are injected at high pressure into a well drilled in a shale formation to break up the rock and release oil and gas.
Now, scientists at the University of Calgary who studied those earthquakes, near Fox Creek in the central part of the province, say the quakes were induced in two ways: by increases in pressure as the fracking occurred, and, for a time after the process was completed, by pressure changes brought on by the lingering presence of fracking fluid.
“The key message is that the primary cause of injection-induced seismicity in Western Canada is different from the central United States,” said David W. Eaton, a professor of geophysics at the University of Calgary and co-author of a paper in the journal Science describing the research. The findings could help regulators take steps to avoid such induced earthquakes, he said.
Scientists say most of the recent earthquakes in Oklahoma and other parts of the United States have been caused by the burial of wastewater from all kinds of oil and gas wells rather than by the fracking process itself. Wastewater is injected under pressure into disposal wells drilled into a sandstone or other permeable formation, and flows into the rock. That can cause pressure changes in the formation that can upset the equilibrium around a fault zone, causing an earthquake as the fault slips.
In the Fox Creek area in Alberta, where oil and gas companies have been drilling in recent years into a formation called the Duvernay shale, earlier research had seen links between the earthquakes — all of which were minor and caused little damage — and fracking, rather than wastewater injection.
They found two patterns to the seismicity. To the east in the fault zone, most of the earthquakes occurred during the fracking process itself, which lasted up to a month. To the west, there were few immediate quakes; they occurred intermittently over several months after the fracking ended.
Dr. Eaton said he and others were conducting more research to understand why Alberta responds differently to fracking than Oklahoma and other parts of the United States. “It’s a different situation,” he said, “and understanding the origin of the differences is important.”
In my book I agreed one cannot stop technology, but that extreme care was needed to avoid the undesired side-effects.
With the deep economic impact of fracturing in the USA the world economics on oil have changed and it has brought sizeable benefits to the U.S.
On the other hand as the article explains, more careful studies are needed to lower the risks. Yes, that might make it more expensive but it is no excuse for damaging the environment.