Why Fracking Works

by Emil Morhardt

We hear a great deal about the economic benefits of hydraulic fracturing, and even more about its potential liabilities, but seldom very much about exactly how fracking works. A fascinating new paper just published by the American Society of Mechanical Engineers (Bazant et al. 2014) combines an extremely clear explanation of the process in non-technical language with a detailed mathematical analysis of the mechanics involved (a combination uncommon in engineering papers). The question at hand is why, with pipes just three-inches in diameter, spaced half a kilometer apart, it is possible to get so much gas out of shale beds. The first thing to know is that even this technology gets only about
5–15% of the gas embedded in the shale, so it’s likely they’ll be going back for more as the technology improves. They know about this percentage because of how much gas they can extract from the rock samples they get out of the well cores. Continue reading