Greens, rejoice! A new, more environmentally-friendly hydraulic fracturing fluid is on its way. Scientists at the Pacific Northwest National Laboratory, which the Department of Energy runs, have been working on an alternative to the chemical-laden slurry that’s currently pumped into horizontal wells in order to fracture shale rock and release oil and gas. The new fluid could save water, reduce the hazards entailed by fracking wastewater, and potentially cut costs for drillers. Scientific American reports:
The [new fracking fluid], developed by Carlos Fernandez of Pacific Northwest National Laboratory and coworkers, expands by up to 2.5 times its original volume in response to carbon dioxide. It is made from poly(allylamine) and could reduce the volume of water required for fracking, as well as being non-toxic, a biocide, and a corrosion inhibitor, circumventing the addition of extra chemicals.
On stimulation with carbon dioxide, Fernandez’s fluid transitions from an aqueous solution to a hydrogel, exerting pressure and stress in the rock as it swells, which initiates fractures. This reduces the requirement for external pressure, and since the transition is reversible via carbon dioxide depressurisation or addition of acid, the fluid can be removed from the rock and recycled, further limiting its environmental impact.
Critics of fracking have long pointed to wastewater problems as one of the key reasons to ban or severely limit fracking. Addressing that problem could thus pave the way for wider acceptance of the controversial process. The fact that it could also lower costs for producers is just the icing on the cake.