Hydraulic Fracturing: what it is, and why we’re talking about it

If you Google ‘hydraulic fracturing,’ you get 3,730,000 results in less than a second. That’s the result I got on January 5, 2012 – you may get a number that varies from that impressive figure if you try it, but the point is, you get a lot of results. I studied geology in college, so I should have had some basic knowledge of this idea of hydraulic fracturing of shale for natural gas… but I really didn’t. I called a friend of mine – a classmate of mine – who is currently a Professional Geologist in the state of North Carolina to ask him what ‘fracking’ is.

– It’s this new technique that’s not really that new in which we drill down to a specific formation [geologists’ language for a specific rock type in its natural extent] and blast a slurry of water and salts and sand to fracture the rock, which lets the fluids trapped in the rock escape more easily. What makes it unique is that it’s done by drilling vertically down to the desired layer, and then the well bore turns to drill directionally along that formation, and that is where the fracturing is done.

A little more elaboration: hydrocarbons are stored in the pores between grains in the rock, and the traditional form of extraction involves identifying where these hydrocarbons have pooled in the subsurface and tapping directly into that. But different rocks have different porosity – the effectiveness with which fluids can migrate through the rock. Fracturing the bottom of conventional oil wells began in the 1940’s to help open those routes for the hydrocarbons and therefore get more production from that well. When industry representatives report that ‘fracking’ has been done for 60-plus years, they are referring to this practice employed in traditional oil and gas wells. Knowing that vast stretches of geological formations, for the most part shale, in the country contained hydrocarbons that conventional oil drilling did not access, the US Department of Energy funded research in the 1980’s to discover ways in which shale gas may be extracted (nice piece in the Washington Post recognizing that history). The technology to drill directionally along the plane of a gas-rich bed of shale and be able to fracture that bed was the key to releasing the hydrocarbons. The practice has been used in this combination of directional drilling and hydrofracturing in Texas since the 1990’s, but is still unconventional: according to Dr. Anthony Ingraffea who helped develop the technique, the technology in its current use was first practiced in 2003.

To better illustrate how hydrofracturing is done, I’ve copied and pasted a nice graphic of hydraulic fracturing from the ProPublica website on the topic.

As stated on the opening post, the injection of fluids into the substrate and directional drilling are both prohibited under current North Carolina law, but since the General Assembly has charged our regulatory agency to review the regulatory framework to permit fracking, I believe that it is very likely that the technique will be permitted in the near future. In a nutshell, that is why we are talking about it. But there are so many wrinkles associated with drilling for hydrocarbons which this state is not accustomed to, and to study the issue thoroughly in the short time frame provided is a challenge.

Perhaps as telling as the research itself is the number of other states that are wrestling with permitting fracking in their state, or have very recently permitted the practice. West Virginia and Colorado have recently permitted it, Ohio, Michigan, and New York are considering it – Ohio is already accepting the spent water from fracking operations in Pennsylvania by injecting the fluids deep into the substrate, a practice that has caused earthquakes measuring as high as 4 on the Richter scale. Remember, injecting fluids into the substrate is prohibited in North Carolina, and in fact, the Safe Drinking Water Act protects underground water resources. So here’s another reason we’re talking about this now: hydraulic fracturing for the extraction of natural gas is exempt from the Safe Drinking Water Act as established in the Energy Policy Act of 2005. There is a good description of the exemption fracking has from both the SDWA and the Clean Water Act (the exemption here is from stormwater controls) has on the StateImpact website. Gas developers do not have to disclose the materials pumped into the substrate, unless they use diesel.

Clearly, this raises questions about the safety of our water supply from the industrial processes used in fracking, the disposal of that frack fluid that returns to the surface, and whatever minerals that migrate from the shale with the natural gas. Much more on this topic is to come on this blog, but it is here that I must turn attention to an episode of This American Life on the subject: ‘Game Changer.

From this episode of This American Life, I discovered two speeches recorded on YouTube that have been very helpful in understanding the issues related to Fracking. The first I include here is a lengthy talk from Dr. Anthony Ingraffea of Cornell University, but it is extremely informative.

Below that is the somewhat alarmist tone from Dr. Conrad Volz, but he raises the excellent point that there is an immediate threat from the process and the need to treat the wastewater produced in the fracking. The threat of contamination from fracking chemicals migrating from the rock formation into the drinking water aquifer may or may not exist, we don’t know yet, but the management of water on the surface is vital.



One thought on “Hydraulic Fracturing: what it is, and why we’re talking about it

  1. Pingback: Water, part one. | NC Triassic Basins water & shale gas

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