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Observations of the release of non-methane hydrocarbons from fractured shale.

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journal contribution
posted on 02.08.2017, 10:44 by Roberto Sommariva, Robert S. Blake, Robert J. Cuss, Rebecca L. Cordell, Jon F. Harrington, Iain R. White, Paul S. Monks
The organic content of shale has become of commercial interest as a source of hydrocarbons, owing to the development of hydraulic fracturing ("fracking"). While the main focus is on the extraction of methane, shale also contains significant amounts of non-methane hydrocarbons (NMHCs). We describe the first real-time observations of the release of NMHCs from a fractured shale. Samples from the Bowland-Hodder formation (England) were analyzed under different conditions using mass spectrometry, with the objective of understanding the dynamic process of gas release upon fracturing of the shale. A wide range of NMHCs (alkanes, cycloalkanes, aromatics, and bicyclic hydrocarbons) are released at parts per million or parts per billion level with temperature- and humidity-dependent release rates, which can be rationalized in terms of the physicochemical characteristics of different hydrocarbon classes. Our results indicate that higher energy inputs (i.e., temperatures) significantly increase the amount of NMHCs released from shale, while humidity tends to suppress it; additionally, a large fraction of the gas is released within the first hour after the shale has been fractured. These findings suggest that other hydrocarbons of commercial interest may be extracted from shale and open the possibility to optimize the "fracking" process, improving gas yields and reducing environmental impacts.

History

Citation

Environmental Science and Technology, 2014, 48 (15), pp. 8891-8896

Author affiliation

/Organisation/COLLEGE OF SCIENCE AND ENGINEERING

Version

AM (Accepted Manuscript)

Published in

Environmental Science and Technology

Publisher

American Chemical Society

issn

0013-936X

eissn

1520-5851

Copyright date

2014

Available date

02/08/2017

Publisher version

http://pubs.acs.org/doi/abs/10.1021/es502508w

Language

en