The connections among CO2, carbon capture and storage technology, and fracking are at once tantalizing and contradictory. Researchers at Kyoto University, Japan, say they have found a way to enhance shale fracturing by replacing conventional, water-intensive hydraulic fracturing with liquid or supercritical CO. Using CO2 instead of water gets more gas to flow, they say.
The Japanese work complements other chemistry-based research being conducted at West Virginia University on the technical and economic viability of using CO to remove methane from shale.
These studies suggest that the use of CO2 in place of water may – may - allow for the extraction of more gas and could extend the productive life of even depleted gas reservoirs. But much more scientific, engineering, and financial/economic work clearly needs to be done before that is proven, much less adopted by industry.
Both sets of researchers point out a potentially huge additional benefit of using CO2 for fracking – it would reduce global warming pollution outright and create an economic driver for carbon capture and storage technology. That is doubly huge because deploying CCS with natural-gas-fired generation offers the potential of near-zero carbon emissions from electricity production.
But here is the rub.
While the U.S. may have 500 years’ worth of geologic storage capacity for carbon emissions, shale that is often the impermeable seal which would prevent stored CO2 from escaping its underground storage.
The CO2-fracking-CCS connection – or conundrum – bears continuing, close scrutiny.