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| Fig. 1: Diagram of Hydraulic Fracking. (Source: Wikimedia Commons) |
Fracking, also known as hydraulic fracturing (displayed in Fig. 1), is the technique used to extract natural gas, oil, and geothermal energy. These resources are found underground and trapped beneath low permeability rocks, which would not be made available without fracking, which was first discovered in 1949. To break up these rocks high pressure fluids, made up of chemicals that have high levels of toxicity, are used to create a path for the natural gas, oil, or geothermal energy to escape and reach the surface. [1] The main issue with fracking used for the recovery of natural gas is due to the release of methane into the atmosphere. Methane is a more potent greenhouse gas than carbon dioxide and contributes more to global warming (given the same amount of methane and carbon dioxide). [2] Another issue with fracking is that the chemical fluid used to fracture the rocks are difficult and costly to recover. These key issues have been a concern as fracking is becoming more abundant and is leaving a growing environmental footprint.
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| Fig. 2: Polymer fiber under microscope. (Source: Wikimedia Commons). |
A new fracturing fluid has been developed by researchers, led by Professor Kenneth C. Carroll, at the University of New Mexico. This new liquid addresses some of the issues of hydraulic fracturing. This new fluid is water based along with 1 percent polyallylamine (a carbon based polymer displayed in Fig. 2), which expands with the addition of carbon dioxide. The fluid turns into a hydrogel expanding, up to 250% in volume, within the cracks of rocks and fractures them. [3,4] The great thing about this process as opposed to that of hydraulic fracturing is that it is much more environmentally friendly. It uses much less water and does not rely on harsh chemicals, while at the same time being more cost effective. Another key improvement is that this new fluid is able fracture bedrock that was previously thought to be impenetrable.
This new fracturing fluid impacts the geothermal, oil, and natural gas industry. This new polymer based fracturing fluid addresses and improves upon the many challenges of hydraulic fracturing. There are still a number tests remaining, including field tests, before it can replace hydraulic fracturing. Unfortunately, the key environmental issue of methane seepage is left unresolved. The process however is much more environmental friendly with the reduction of water and chemical usage.
© Rosco Allen. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
[1] M. K. Hubbert, D. G. Willis, "Mechanics of Hydraulic Fracturing," in Waste Management and Environmental Implications, ed. by T. D. Cook (Am. Association of Petroleum Geologists, 1972), p. 239.
[2] N. Oreskes, "The Centerpiece of Obama's Energy Policy Will Actually Make Climate Change Worse," The Nation, 28 Jul 14.
[3] H. Shao et al., "Environmentally Friendly, Rheoreversible, Hydraulic-Fracturing Fluids For Enhanced Geothermal Systems," Geothermics 58, 22 (2015).
[4] H. B. Jung et al., "Stimuli-Responsive/Rheoreversible Hydraulic Fracturing Fluids as a Greener Alternative to Support Geothermal and Fossil Energy Production," Green Chem. 17, 2799 (2015).
