Liquid nitrogen waterless fracking for the environmental protection of arid areas during unconventional resource extraction

March 04, 2020

Hong Yan(1,2), Lipeng Tian(1), Ruimin Feng(3), Hani Mitri(2), Junzhi Chen(1), Kang He(1), Yuan Zhang(1), Shunchao Yang(1), Zhijun Xu(1)
Science of the Total Environment, 721, March 2020. DOI: 10.1016/j.scitotenv.2020.137719


Arid and semi-arid regions, Liquid nitrogen (LN2), Unconventional resources extraction, 3D micro CT, Fracturing effect


Many arid and semi-arid regions are rich in shale gas or coalbed methane. However, hydraulic-fracturing, commonly used for reservoir stimulation, has serious environmental impacts such as the consumption of large quantities of water, damage of residual organic compounds and the disposal of process water. This paper presents liquid nitrogen (LN2) as an environmentally friendly, waterless fracking technology, which could potentially replace hydraulic fracturing. Laboratory experiments on LN2 fracturing were conducted on coal samples, and high-resolution micro X-ray computed tomography was used for 3D visualization and evaluation of fracture evolution characteristics, including liquid nitrogen cyclic quenching, effect of initial fracture size (IFS) and coal saturation. The findings of this study testify to the effectiveness of fracturing by LN2 quenching on coalbed methane reservoirs. This technique would help protect water resources and alleviate other environmental concerns in arid districts during unconventional resource recovery.

How Our Software Was Used

Dragonfly was used for 3D visualization and analysis of coal samples.

Author Affiliation

(1) Key Laboratory of Deep Coal Resource Mining, Ministry of Education of China, School of Mines, China University of Mining & Technology, Xuzhou 221116, China.
(2) Department of Mining and Materials Engineering, McGill University, Montreal H3A 0E8, Canada.
(3) Department of Chemical and Petroleum Engineering, University of Calgary, Calgary T2N 1N4, Canada.